[paul alan]

Today I will be installing an immersion heater into my tank.

I am putting a 16a mcb in the consumer and from that I am going into a 16a timer that will go on the wall next to the consumer unit then drilling through the wall to send a 2.5mm 3core cable(for outdoor use) to run down the wall which will connect to a 16a socket in my box I use for ro and booster pump.

I then have a 16a extension cord that will go through to the van and connect to the 3kw element that I hope still works or else I have a real pia on my hands taking it out and replacing as its near the bottom of a 650ltr wydale upright tank.

All going well I will have a nice hot tank of water in the morning.

Should I schedule some time breaks whilst on overnight ?  maybe 2 hours on 30 minutes off? or is this unnecessary as I'm using a full 16a setup?

I think I will order a temp sensor that I can drop into the tank as I have plumbers mate'd the lid shut to stop leaks from happening, so wont be able to take temp readings that way .

Can I expect leaky connectors etc now its all going hot?

[֍Winp®oClean֍]

Congrats on going about this the correct and safe way. Your set up is the same as mine.
No need for time breaks, I would start with 8 hours and see how you get on.
If the element is fitted to the tank via a mechanical flange (looks like a big brass nut which slightly bells out to a flat surface to meet the tank wall) then replacing the element is a doddle- simple as draining the tank, unscrew the old and screw a new one in.

[nathankaye]

Sounds good buddy, but yes you may find that all the connections may become loose. I definitely had to tighten and indeed change some connections.
Infact from my pump to the reel ive used a car radiator pipe as my reinforced plastic one, sprung a leak. I also have it fitted direct to my swivel connector and all other connections ive had to tighten, ie the filter before the pump has to be tightened many a times

[AuRavelling79]

As Peavey said. But ...

As it's a new install I would put it on and watch like a hawk for a couple of hours. If all is cool (as in joints and switches not getting over warm) then great!

Oh ... and make sure the water in the tank covers the element ... EVERY TIME. 

[Seymour Sunshine]

From your description, it certainly looks like you know what you're doing. Personally, I would put it on a timer. The temperature calculations are impossible to do as there are too many unknown factors, but a 3kW heater for 8 hours will consume 24 kWh.

You don't really want to be heating the water to very warm temperatures. There are rules about legionella regarding heating tanks of water. You are going to be spraying this water on several customers' properties every day. I'd be very wary of getting hot water in this way .. it's a serious disease.

This is taken from HSE: http://www.hse.gov.uk/healthservices/legionella.htm

What is legionella?
Legionella bacteria is commonly found in water. The bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C.

My advice would be to just warm the water a little and keep the temperature well below the 20°C limit. Whatever you do, don't warm to water regularly to between the 20 and 45 limits. Hence use a timer.

[paul alan]

From your description, it certainly looks like you know what you're doing. Personally, I would put it on a timer. The temperature calculations are impossible to do as there are too many unknown factors, but a 3kW heater for 8 hours will consume 24 kWh.

You don't really want to be heating the water to high temperatures. There are rules about legionella regarding heating large quantities of water. You are going to be spraying this water on customers' properties. I'd be very wary of getting hot water in this way .. it's a serious disease.

This is taken from HSE: http://www.hse.gov.uk/healthservices/legionella.htm

What is legionella?
Legionella bacteria is commonly found in water. The bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C.

My advice would be to just warm the water a little and keep the temperature well below the 20°C limit. Whatever you do, don't warm to water regularly to between the 20 and 45 limits. Hence use a timer.

I think water has to sit a certain temp for around 5 days before the bacteria can grow?

will be checking this out but thanks for the heads up!

[Seymour Sunshine]

Where a very serious disease like this is concerned, I would be very careful. The simple solution is to keep the temperature low, hence use a timer.

I had this idea and discussed this with my son who's a plumber. He jumped out of his seat and almost yelled at me not to do it for this very reason. There's a reason that window cleaners use an "on demand" system for hot water, and this is it.

It's an excellent way of keeping the water at a good operating temperature, but not for heating. Hence my suggestion of using a timer to limit the temperature rises. I guess that 15 minutes on and 2 hours off should be about right.

[Tony dunmall]

This a Main reason why I’ve NOT ventured down the line of an immersion as there is a small risk-unless you take precautions,emptying the tanks or part filling with cold to safety temperature then  flushing through the hoses then starting process again in morning of heating,as often I don’t use a whole tank

But correct me if I’m wrong, after reading much about the hot water threads recently. It seems that some companies have a return to the tank which will heat the water in the tank and I’m not talking about the froststat setting for during the early hours to prevent freszzing of Hoses and pumps

If this is the case and water is automatically recirculated to tank keeping heaters working constantly to maintain good health of heater

and some say by middle morning there tanks water are very Hot

This is no difference in my opinion than using an Electric element

So if this is the case then it’s scarmongering to keep people buying the more expensive heaters which companies are fitting

Just my thoughts

As I’m looking at fittings out the vans for Hot and it’s a high expense at minimum I’ve two vans maybe three that’s nearly 10K just for hot few months a year

[Susan Dean (1stclean)]

Where a very serious disease like this is concerned, I would be very careful. The simple solution is to keep the temperature low.

I had this idea and discussed this with my son who's a plumber. He jumped out of his seat and almost yelled at me not to do it for this very reason. There's a reason that window cleaners use an "on demand" system for hot water, and this is it.

It's an excellent way of keeping the water at a good operating temperature, but not for heating.

or not bother at all and just leave the tank empty from friday night until sunday when you start heating the water for monday ? this way it dies with the cold on a saterday meaning you can have the water any heat you want ?

[paul alan]

Where a very serious disease like this is concerned, I would be very careful. The simple solution is to keep the temperature low.

I had this idea and discussed this with my son who's a plumber. He jumped out of his seat and almost yelled at me not to do it for this very reason. There's a reason that window cleaners use an "on demand" system for hot water, and this is it.

It's an excellent way of keeping the water at a good operating temperature, but not for heating.

or not bother at all and just leave the tank empty from friday night until sunday when you start heating the water for monday ? this way it dies with the cold on a saterday meaning you can have the water any heat you want ?

good point!

I will be heating tank night before it gets used next day.

if there is anything left in it will get neutralised when I fill up with cold again when home.

There is a young ish fella up the street from me with a van that has legionella risk assessment written on the side, ill go and knock on for a chat soon.

Granville and Nathan , what are your thought's on this??

[paul alan]

Where a very serious disease like this is concerned, I would be very careful. The simple solution is to keep the temperature low, hence use a timer.

I had this idea and discussed this with my son who's a plumber. He jumped out of his seat and almost yelled at me not to do it for this very reason. There's a reason that window cleaners use an "on demand" system for hot water, and this is it.

It's an excellent way of keeping the water at a good operating temperature, but not for heating. Hence my suggestion of using a timer to limit the temperature rises. I guess that 15 minutes on and 2 hours off should be about right.

I am also a qualified plumber and as far as I can remember the water has to sit at a certain temp for a length of time to grow the bacteria, if the water is being heated and used on a daily cycle I see no problems.
but I will go and look into it further.

[Seymour Sunshine]

Where a very serious disease like this is concerned, I would be very careful. The simple solution is to keep the temperature low.

I had this idea and discussed this with my son who's a plumber. He jumped out of his seat and almost yelled at me not to do it for this very reason. There's a reason that window cleaners use an "on demand" system for hot water, and this is it.

It's an excellent way of keeping the water at a good operating temperature, but not for heating.

or not bother at all and just leave the tank empty from friday night until sunday when you start heating the water for monday ? this way it dies with the cold on a saterday meaning you can have the water any heat you want ?

good point!

I will be heating tank night before it gets used next day.

if there is anything left in it will get neutralised when I fill up with cold again when home.

There is a young ish fella up the street from me with a van that has legionella risk assessment written on the side, ill go and knock on for a chat soon.

Granville and Nathan , what are your thought's on this??

Yes, you're absolutely right to go have a chat with someone who really knows about this. I'm looking at things from a purely theoretical point of view as I have no direct experience or education in this particular field.

Just a point to bear in mind: the little sods are dormant below 20 deg. They aren't killed.

[Dry Clean]

1. Even with the variables its very easy to work out heating times.
2. As we have little or no nutrients in our pure then the risk of Legionella is virtually non existent.

[paul alan]

Where a very serious disease like this is concerned, I would be very careful. The simple solution is to keep the temperature low.

I had this idea and discussed this with my son who's a plumber. He jumped out of his seat and almost yelled at me not to do it for this very reason. There's a reason that window cleaners use an "on demand" system for hot water, and this is it.

It's an excellent way of keeping the water at a good operating temperature, but not for heating.

or not bother at all and just leave the tank empty from friday night until sunday when you start heating the water for monday ? this way it dies with the cold on a saterday meaning you can have the water any heat you want ?

good point!

I will be heating tank night before it gets used next day.

if there is anything left in it will get neutralised when I fill up with cold again when home.

There is a young ish fella up the street from me with a van that has legionella risk assessment written on the side, ill go and knock on for a chat soon.

Granville and Nathan , what are your thought's on this??

Yes, you're absolutely right to go have a chat with someone who really knows about this. I'm looking at things from a purely theoretical point of view as I have no direct experience or education in this particular field.

Just a point to bear in mind: the little sods are dormant below 20 deg. They aren't killed.

Dormant is fine with me.

[Seymour Sunshine]

1. Even with the variables its very easy to work out heating times.
2. As we have little or no nutrients in our pure then the risk of Legionella is virtually non existent.

1 - I'd be very interested to see how you do your calculations. Heat in is no problem: Q = VIt. But how do you calculate the heat losses? It comes to a very nasty differential equation with an exponential solution. And you have to make many assumptions about conductivity and emissivity. If you can do that, you're a better mathematician than I am. ... which, of course, you might be.
2 - In that case, why do we have algae growing in our IBCs?

I'd be very wary of saying that the risk of spreading a deadly disease is virtually non-existent when you are warming and cooling large quantities of water repeatedly and then spraying it onto people's houses.

[tony day]

1. Even with the variables its very easy to work out heating times.
2. As we have little or no nutrients in our pure then the risk of Legionella is virtually non existent.

1 - I'd be very interested to see how you do your calculations. Heat in is no problem: Q = VIt. But how do you calculate the heat losses? It comes to a very nasty differential equation with an exponential solution. And you have to make many assumptions about conductivity and emissivity. If you can do that, you're a better mathematician than I am. ... which, of course, you might be.
2 - In that case, why do we have algae growing in our IBCs?

I'd be very wary of saying that the risk of spreading a deadly disease is virtually non-existent when you are warming and cooling large quantities of water repeatedly and then spraying it onto people's houses.

If a window cleaner can work out conductivity & emissivty then he shouldn't be a window cleaner!

[paul alan]

All fitted and ready to go.

All wired up according to the regs, I just hope that when I turn it on the element is still working.

Just waiting for some water to fill so I can test it.

on legionella:
A very effective chemical treatment is chlorine. For systems with marginal issues, chlorine provides effective results at 0.5 ppm[citation needed] residual in the hot water system. For systems with significant Legionella problems, temporary shock chlorination—where levels are raised to higher than 2 ppm for a period of 24 hours or more and then returned to 0.5 ppm may be effective.[citation needed] Hyperchlorination can also be used where the water system is taken out of service and the chlorine residual is raised to 50 ppm or higher at all distal points for 24 hours or more. The system is then flushed and returned to 0.5 ppm chlorine prior to being placed back into service. These high levels of chlorine penetrate biofilm, killing both the Legionella bacteria and the host organisms. Annual hyperchlorination can be an effective part of a comprehensive Legionella preventive action plan.[31

Where does the legionella bacteria occur?
The bacteria causing the disease can be found in very small quantities in the ground, and in water and tap water. The legionella bacteria becomes a problem when it is able to multiply, e.g. in water with a temperature between 25o and 55o Celsius that is stagnant for a long period of time. A strong flow can prevent the growth of the bacteria, but if this flow is not constant throughout an entire hot water system, water could become stagnant in certain spots (so-called dead corners), where further growth could occur, creating a risk.

Controlling legionella bacteria
Legionella bacteria can multiply to dangerous concentrations in five days. A simple and effective way of controlling the bacteria in hot water systems, is to increase the water temperature. This will start to kill the bacteria at around 50ºC and if the water temperature reaches 60ºC and is held at that temperature for sufficient time (usually about 10 minutes), the bacteria will be killed. Satisfactory routine control of legionella bacteria will be achieved if a temperature of 60ºC is maintained throughout the cylinder for a period of one hour each day.
Heating the water to 60ºC will kill the bacteria but there is an increased risk of skin burns (scalding). Fitting a thermostatic mixing valve (TMV) allows the water to be stored and distributed at high temperature while blending it with cold water before it reaches the tap. (Building Regulation Part G required the fitting of TMVs as standard on baths in new homes.)
Water in storage cisterns should not be allowed to exceed 20ºC.

[֍Winp®oClean֍]

Easy way to tell if the element is working is to look at your electric meter- if it's working it will be flying round!!

[Seymour Sunshine]

All fitted and ready to go.

All wired up according to the regs, I just hope that when I turn it on the element is still working.

Just waiting for some water to fill so I can test it.

on legionella:
A very effective chemical treatment is chlorine. For systems with marginal issues, chlorine provides effective results at 0.5 ppm[citation needed] residual in the hot water system. For systems with significant Legionella problems, temporary shock chlorination—where levels are raised to higher than 2 ppm for a period of 24 hours or more and then returned to 0.5 ppm may be effective.[citation needed] Hyperchlorination can also be used where the water system is taken out of service and the chlorine residual is raised to 50 ppm or higher at all distal points for 24 hours or more. The system is then flushed and returned to 0.5 ppm chlorine prior to being placed back into service. These high levels of chlorine penetrate biofilm, killing both the Legionella bacteria and the host organisms. Annual hyperchlorination can be an effective part of a comprehensive Legionella preventive action plan.[31

Where does the legionella bacteria occur?
The bacteria causing the disease can be found in very small quantities in the ground, and in water and tap water. The legionella bacteria becomes a problem when it is able to multiply, e.g. in water with a temperature between 25o and 55o Celsius that is stagnant for a long period of time. A strong flow can prevent the growth of the bacteria, but if this flow is not constant throughout an entire hot water system, water could become stagnant in certain spots (so-called dead corners), where further growth could occur, creating a risk.

Controlling legionella bacteria
Legionella bacteria can multiply to dangerous concentrations in five days. A simple and effective way of controlling the bacteria in hot water systems, is to increase the water temperature. This will start to kill the bacteria at around 50ºC and if the water temperature reaches 60ºC and is held at that temperature for sufficient time (usually about 10 minutes), the bacteria will be killed. Satisfactory routine control of legionella bacteria will be achieved if a temperature of 60ºC is maintained throughout the cylinder for a period of one hour each day.
Heating the water to 60ºC will kill the bacteria but there is an increased risk of skin burns (scalding). Fitting a thermostatic mixing valve (TMV) allows the water to be stored and distributed at high temperature while blending it with cold water before it reaches the tap. (Building Regulation Part G required the fitting of TMVs as standard on baths in new homes.)
Water in storage cisterns should not be allowed to exceed 20ºC.

Well, there you go. Just a couple of teaspoons of bleach (bleach is about 5% free Cl) in the tank and you've got no worries at all.  But please check my calculation. That's what I love about this forum: we're a group of problem-solvers.

I hope my input was useful in some way. I'm genuinely trying to be helpful and supportive. If I come across as being a nit-picker, it's because I am! But I'm a good-hearted and generous nit-picker.

[alank]

So should we all be adding bleech to our water now?

[nathankaye]

Legionnaires disease is with stagnant water as well. The water in your tank that your heating is only stagnant during the night whilst it is heating/warming. During the working day it is nothing like stagnant water.  Also I believe you need to have particles ie rust for an example in your tank for it to latch onto.
So in the case of us window cleaners using pure water heated in a tank and drove around for work.... It is a risk which is extremely unlikely to occur

[paul alan]

Its working, I can tell thanks to peavey as the lecy meter is blinking twice as fast now.

[֍Winp®oClean֍]

Its working, I can tell thanks to peavey as the lecy meter is blinking twice as fast now.

My advice is be reasonable with your expectations. You're not going to have steaming hot water hitting the glass unless you literally boil the tank- which would take a very long time. However, if you leave your van tank uninsulated it will act as a giant radiator and nothing in your van will freeze- regardless of outside temps. Also, your whole system, hoses etc will remain lovely and supple all day. For me the above is more beneficial than a "on-demand" diesel heater but.... the immersion IMO is not a realistic replacement for a proper hot water system. However, it does keep you working comfortably all winter with no freezing issues.👍

[alank]

You couldn't call my water stagnant the way I drive.

[Seymour Sunshine]

So should we all be adding bleech to our water now?

No! Not all. And nowhere does it say "all."

But if you're holding your water at above-ambient temperatures for long periods and you want to be safe rather than sorry, then it makes sense to take all possible precautions. Did you deliberately misunderstand or are you simply taking the excess water from well-meaning people's kidneys?

[dazmond]

Every year it's the same old fears about legionnaires disease.does anybody know of any window cleaner who has ever  contracted it?..... No I didn't think so.

That's because we don't store water above 20c for long periods of time.thats when it COULD breed.not when your heating water to use the very next day.

[alank]

Not at all taking the p, at this time if year heated water used and re filled daily. more bothered If water left in tank during summer when temperatures are higher anyway.would it then be beneficial to bleech?

[Dry Clean]

1. Even with the variables its very easy to work out heating times.
2. As we have little or no nutrients in our pure then the risk of Legionella is virtually non existent.

1 - I'd be very interested to see how you do your calculations. Heat in is no problem: Q = VIt. But how do you calculate the heat losses? It comes to a very nasty differential equation with an exponential solution. And you have to make many assumptions about conductivity and emissivity. If you can do that, you're a better mathematician than I am. ... which, of course, you might be.
2 - In that case, why do we have algae growing in our IBCs?

I'd be very wary of saying that the risk of spreading a deadly disease is virtually non-existent when you are warming and cooling large quantities of water repeatedly and then spraying it onto people's houses.

If a window cleaner can work out conductivity & emissivty then he shouldn't be a window cleaner!

Why is it some people aren't happy unless they're making the easiest of things as hard as possible, if you want to work out
how long it will take to heat your water there's a calculator, this will give you the maximum temp possible in the time available,
I'm sure there will also be one for heat loss but as we aren't trying to get our water to an exact temp then if you allow minus 5 to 10degrees you wont be far away.
As for Legionella, considering the amount of people who have been heating and storing hot water over the years without a single
outbreak plus all the other factors then the evidence points to it not being of any concern.

[Seymour Sunshine]

Why is it some people aren't happy unless they're making the easiest of things as hard as possible, if you want to work out
how long it will take to heat your water there's a calculator, this will give you the maximum temp possible in the time available,
I'm sure there will also be one for heat loss but as we aren't trying to get our water to an exact temp then if you allow minus 5 to 10degrees you wont be far away.
As for Legionella, considering the amount of people who have been heating and storing hot water over the years without a single
outbreak plus all the other factors then the evidence points to it not being of any concern.

My input, which has been made with no other motivation than to be helpful and useful, can be simplified (without losing anything of importance) to:

* An immersion heater is a far more energy-efficient way of keeping the water in your van tank from freezing than using a space heater.

* Heating and cooling water over long periods could lead to a buildup of potentially dangerous levels of highly toxic legionella.

What is hard about that?

[paul alan]

Why is it some people aren't happy unless they're making the easiest of things as hard as possible, if you want to work out
how long it will take to heat your water there's a calculator, this will give you the maximum temp possible in the time available,
I'm sure there will also be one for heat loss but as we aren't trying to get our water to an exact temp then if you allow minus 5 to 10degrees you wont be far away.
As for Legionella, considering the amount of people who have been heating and storing hot water over the years without a single
outbreak plus all the other factors then the evidence points to it not being of any concern.

My input, which has been made with no other motivation than to be helpful and useful, can be simplified (without losing anything of importance) to:

* An immersion heater is a far more energy-efficient way of keeping the water in your van tank from freezing than using a space heater.

* Heating and cooling water over long periods could lead to a buildup of potentially dangerous levels of highly toxic legionella.

What is hard about that?

Granted seymor, and I do appreciate your input as its best to be safe than sorry.

But I think the point is, its a different fresh tank of water each day. As long as being careful it shouldn't pose a problem.

Thanks for your input as its good to have your thinking tested by others.

[paul alan]

Its working, I can tell thanks to peavey as the lecy meter is blinking twice as fast now.

My advice is be reasonable with your expectations. You're not going to have steaming hot water hitting the glass unless you literally boil the tank- which would take a very long time. However, if you leave your van tank uninsulated it will act as a giant radiator and nothing in your van will freeze- regardless of outside temps. Also, your whole system, hoses etc will remain lovely and supple all day. For me the above is more beneficial than a "on-demand" diesel heater but.... the immersion IMO is not a realistic replacement for a proper hot water system. However, it does keep you working comfortably all winter with no freezing issues.👍

And this is the main reason I have completed this project today, frost prevention.

I would imagine if at some point I did want piping hot water at the brush head and I did install one of them water heaters it would use less fuel to get the water up to temp if the immersion has pre-heated the water.

Kind of like these new hybrid engines, dual fuel's to achieve a "hot" outcome.

[nathankaye]

 But initially i wanted hot water, for cleaning and mostly for the softer hoses. To that affect I started by using 500watt fish tank heaters submerged in my tank. I was able fo get into the 40's using them overnight. Now that was great for warming up the hose and I started to see a difference in cleaning as well and that set me off wanting hot water and deciding upon the Immersion heater route to get it.

So basically im saying, that once youve seen the benefits and advantages of using hot you may not have the main aim of only doing so to keep the frost at bay.
( I think the ones who say that after a long time using it, is because of the running costs of doing so.)

[Jonny 87]

But initially i wanted hot water, for cleaning and mostly for the softer hoses. To that affect I started by using 500watt fish tank heaters submerged in my tank. I was able fo get into the 40's using them overnight. Now that was great for warming up the hose and I started to see a difference in cleaning as well and that set me off wanting hot water and deciding upon the Immersion heater route to get it.

So basically im saying, that once youve seen the benefits and advantages of using hot you may not have the main aim of only doing so to keep the frost at bay.
( I think the ones who say that after a long time using it, is because of the running costs of doing so.)

Nathan it would take about 18 hours to heat cold water of say 10 degrees up to 40 degrees.

Just in case someone reads this and decides to waste money on a 1kw heater.

The only way you could possibly achieve that is if regularly you have half a tank of water left from the day still warm, and your start temp will Gradually start to rise if that repeats for a few days.

For the average guy like me who nearly drains their tank every day, a 2kw is needed to get anywhere near that. Even then it will
Still need about 9 hours to get there.

This is a very accurate calculator of heat/volume/time.

http://www.jimsbeerkit.co.uk/calc.html

[nathankaye]

But initially i wanted hot water, for cleaning and mostly for the softer hoses. To that affect I started by using 500watt fish tank heaters submerged in my tank. I was able fo get into the 40's using them overnight. Now that was great for warming up the hose and I started to see a difference in cleaning as well and that set me off wanting hot water and deciding upon the Immersion heater route to get it.

So basically im saying, that once youve seen the benefits and advantages of using hot you may not have the main aim of only doing so to keep the frost at bay.
( I think the ones who say that after a long time using it, is because of the running costs of doing so.)

Nathan it would take about 18 hours to heat cold water of say 10 degrees up to 40 degrees.

Just in case someone reads this and decides to waste money on a 1kw heater.

The only way you could possibly achieve that is if regularly you have half a tank of water left from the day still warm, and your start temp will Gradually start to rise if that repeats for a few days.

For the average guy like me who nearly drains their tank every day, a 2kw is needed to get anywhere near that. Even then it will
Still need about 9 hours to get there.

This is a very accurate calculator of heat/volume/time.

http://www.jimsbeerkit.co.uk/calc.html

In the reference to fish tank heaters which you quoted, i believe my sentence was "heaters" as in more than one and anybody can use the search feature on here where in the past I said i used several heaters.
Fetching it forward, i promote the use of Immersion heaters as a great and safe way of achieving hot water, along with insulating the tank.   Perhaps i and others should state the obvious in saying "do your research and do so safely" but I thought common sense would prevail.
Now for me and the size of the tank and how much water I use, along with the different starting temps that I have then my immersion works pretty well and I achieve HOT water as shown in many of my vids on my channel. Ive also in the past said the reason I use a 1kw is because I currently rent and cannot mess about with the electrics.
In addition I had a private conversation with someone about immersion heaters and recommended a 2kw. In addition the heat calculators are  not truly accurate but give a good indication, because if they were right that would mean that I would have to come home, fill up and stick the heater on straight away. It would also mean that my electric bill would be extremely high and I certainly would not be running it through the summer montbs like I have been doing.

But, if I owned my own house I would be wanting the biggest and best heater I could afford to get. For me that would be a 3kw 27" inch long  element

[Seymour Sunshine]

I absolutely promise that this will be my last contribution to this thread.

The calculator mentioned is NOT accurate as it takes no account whatsoever of heat losses. I've had a look at the source code and all it does is to calculate the energy input and then calculate the temperature rise for a given mass of water. The heat loss would be very difficult to calculate since it depends on:

* surface area of the tank
* colour and surface texture of the tank
* material and thickness of the tank
* ambient temperature

and possibly some other factors I haven't considered.

It is absolutely wrong to think that twice the power will give twice the temperature rise or the same temperature rise in half the time etc. It is not anywhere near a linear relationship.

What is true to say is that the temperature will rise until the rate of heat gain from the heater is equal to the amount of heat lost by conduction, convection and mainly radiation. Then it will remain constant. A more powerful heater will get the water hotter and more quickly than a less powerful one. But please believe me, the physics is messy (and is the basis, believe it or not, for the early development of quantum mechanics) and the maths is horrendous!

To give you a flavour of the complexity of it:

* conduction depends on the thickness and surface area of the material and the temperature differences either side of the material
* convection depends on the surface area and orientation of the sides of the tank as well as the temperature
* radiation depends on the 4th power of the temperature difference, the colour and texture of the tank and the temperature and  area of the surroundings.

TBH all this isn't really that important. The important thing is that Paul has successfully installed an immersion heater and that he is aware of all the implications. As long as he reaches his goal of protecting his equipment safely, economically and with the least amount of messing about, I think he's done brilliantly.

[Jonny 87]

But initially i wanted hot water, for cleaning and mostly for the softer hoses. To that affect I started by using 500watt fish tank heaters submerged in my tank. I was able fo get into the 40's using them overnight. Now that was great for warming up the hose and I started to see a difference in cleaning as well and that set me off wanting hot water and deciding upon the Immersion heater route to get it.

So basically im saying, that once youve seen the benefits and advantages of using hot you may not have the main aim of only doing so to keep the frost at bay.
( I think the ones who say that after a long time using it, is because of the running costs of doing so.)

Nathan it would take about 18 hours to heat cold water of say 10 degrees up to 40 degrees.

Just in case someone reads this and decides to waste money on a 1kw heater.

The only way you could possibly achieve that is if regularly you have half a tank of water left from the day still warm, and your start temp will Gradually start to rise if that repeats for a few days.

For the average guy like me who nearly drains their tank every day, a 2kw is needed to get anywhere near that. Even then it will
Still need about 9 hours to get there.

This is a very accurate calculator of heat/volume/time.

http://www.jimsbeerkit.co.uk/calc.html

In the reference to fish tank heaters which you quoted, i believe my sentence was "heaters" as in more than one and anybody can use the search feature on here where in the past I said i used several heaters.
Fetching it forward, i promote the use of Immersion heaters as a great and safe way of achieving hot water, along with insulating the tank.   Perhaps i and others should state the obvious in saying "do your research and do so safely" but I thought common sense would prevail.
Now for me and the size of the tank and how much water I use, along with the different starting temps that I have then my immersion works pretty well and I achieve HOT water as shown in many of my vids on my channel. Ive also in the past said the reason I use a 1kw is because I currently rent and cannot mess about with the electrics.
In addition I had a private conversation with someone about immersion heaters and recommended a 2kw. In addition the heat calculators are  not truly accurate but give a good indication, because if they were right that would mean that I would have to come home, fill up and stick the heater on straight away. It would also mean that my electric bill would be extremely high and I certainly would not be running it through the summer montbs like I have been doing.

But, if I owned my own house I would be wanting the biggest and best heater I could afford to get. For me that would be a 3kw 27" inch long  element

No need to get defensive mate!

I’m with you on the immersion heaters, I used one for years. I just think your figures are out, perhaps due to you regularly having half a tank of water left, and so your heating up already warm water. That’s why I mentioned it, because someone like me who regularly drains their tank nearly empty, I would never achieve the same figures.

As of February this year you said you used 2 x 500watt heaters, that’s why it stuck in my mind, and that’s why I did the figures of 1kw of power taking 18 hours to heat up. 

[Dry Clean]

The heat calculator will give you the maximum heat achievable, that said because of heat lose obviously you wont get to the calculated level.
They are a handy tool though if you get guys coming on claiming to get all sorts of heat from underpowered immersions as they
do prove what its not possible to get.

[AuRavelling79]

Further back I was asked about my thoughts on legionnaires.

Short answer - don't believe it to be a possible problem.

Long answer - as to why I believe that.

My tank heating is primarily for frost protection and supple hoses in cold weather. Rarely I want warmer water for a dirty first clean but no more than a few times a year.

So typically I will heat the water for 4 to 6 hours at some point between 6pm the night before and 8 am on the day I drive off. Typically I do not bother if the temperature outside will be above ten degrees celsius and the water in my tank above about 12 degrees.

Let's give a typical situation when I will use warm water - like last week when daytime temps were about 7 degrees and night time about 0 to 2 degrees.  So I think "bit nippy lets put in four hours of heat" into 400 litres of water.  At 10 pm the water in my tank is about 10 degrees and in the morning it's about 30 degrees.

I go to work and use, say 350 litres and at the end of the day (3/4pm) the temperature of the remaining water is 20 degrees. By 10pm it's about 12 degrees.

So I think "what's the weather from now 'til tomorrow? Milder - less or no heat - maybe an hour or two in the morning from 6 am. Colder? Give it another 4 hours. What's the water temp in my insulated main storage tanks? (usually five/ten degrees higher than ambient in the winter)

Not an exact science - but the hottest temp in my van tank will be 40 degrees in the morning, back to 20 degrees by bed time and less when I add water from my storage tanks.

So when and how long is my water at 20 to 40 degrees? 3 hours - during final heating time. (say 6 am to 9 am.)  Followed by six/seven hours dropping to the 20's when either it will be topped up with cooler water
or if not working the next day it will be below 20 degrees by bed time.

So the absolute maximum the water can be at 20 to 40 degrees is about fifteen hours. Then it will be replaced/topped up or sit at a cooler temperature.

So I don't worry.

[alank]

Thanks gold

[paul alan]

Nice warm van this morning!

[alank]

Excellent glad it's all working for you

[Seymour Sunshine]

Further back I was asked about my thoughts on legionnaires.

Short answer - don't believe it to be a possible problem.

Long answer - as to why I believe that.

My tank heating is primarily for frost protection and supple hoses in cold weather. Rarely I want warmer water for a dirty first clean but no more than a few times a year.

So typically I will heat the water for 4 to 6 hours at some point between 6pm the night before and 8 am on the day I drive off. Typically I do not bother if the temperature outside will be above ten degrees celsius and the water in my tank above about 12 degrees.

Let's give a typical situation when I will use warm water - like last week when daytime temps were about 7 degrees and night time about 0 to 2 degrees.  So I think "bit nippy lets put in four hours of heat" into 400 litres of water.  At 10 pm the water in my tank is about 10 degrees and in the morning it's about 30 degrees.

I go to work and use, say 350 litres and at the end of the day (3/4pm) the temperature of the remaining water is 20 degrees. By 10pm it's about 12 degrees.

So I think "what's the weather from now 'til tomorrow? Milder - less or no heat - maybe an hour or two in the morning from 6 am. Colder? Give it another 4 hours. What's the water temp in my insulated main storage tanks? (usually five/ten degrees higher than ambient in the winter)

Not an exact science - but the hottest temp in my van tank will be 40 degrees in the morning, back to 20 degrees by bed time and less when I add water from my storage tanks.

So when and how long is my water at 20 to 40 degrees? 3 hours - during final heating time. (say 6 am to 9 am.)  Followed by six/seven hours dropping to the 20's when either it will be topped up with cooler water
or if not working the next day it will be below 20 degrees by bed time.

So the absolute maximum the water can be at 20 to 40 degrees is about fifteen hours. Then it will be replaced/topped up or sit at a cooler temperature.

So I don't worry.

Sounds like a very intelligent way of going about things ... economical and well-considered. You've experimented and found out what works. Good for you.

[paul alan]

oh my....the warm water goes so much quicker!!!

Had to come home fro a top up, will have to turn the flow down.

[dazmond]

oh my....the warm water goes so much quicker!!!

Had to come home fro a top up, will have to turn the flow down.

how big is your tank?

[paul alan]

oh my....the warm water goes so much quicker!!!

Had to come home fro a top up, will have to turn the flow down.

how big is your tank?

650

[֍Winp®oClean֍]

You should lower the pressure cut off on the controller- it thinks it's now peak summer!

[paul alan]

Yes..... and so do the well behaved hose's.

[nathankaye]

Wow, 650 ltrs used up by 12.52pm.   What flow do you work on?
Do you usually finish all the tank by the end of the  day?
I must admit i use more water hot than I did cold, but Ive not drained the tank. Lol ive come close to doing so though. But I find if i work on a lower flow I dont keep the higher heat at the brush end.

What temp did you get the tank to in the end?

[combat1]

Combat is packing up window cleaning and joining the Foreign Legionellaires! Get it?

[paul alan]

Wow, 650 ltrs used up by 12.52pm.   What flow do you work on?
Do you usually finish all the tank by the end of the  day?
I must admit i use more water hot than I did cold, but Ive not drained the tank. Lol ive come close to doing so though. But I find if i work on a lower flow I dont keep the higher heat at the brush end.

What temp did you get the tank to in the end?

not sure as I have sealed the lid some time ago as it was leaking.

I have a digital thermometer on the way so I can drop the sensor in the tank. It was warm at best, could feel warm through the hose and in the van too.

I had the heater on from 5pm-7pm. then 1am-3am then 4am-6am then 7am-9am. in 650ltr.

Today I would normally use 450-500 ltr. by midday I could tell I had used more than normal and was close to home so I topped up just in-case. I reckon I have used 650ltr today altogether.

The first half of the day was worst, then I turned flow down to accommodate the heat and things levelled out.

I started the day with a14" with 4x2mm jets but wasn't satisfied with the flow so I switched to a tucker 12" on pencil jets but the pencils in the tucker must 1mm or something similar and the flow was way too aggressive. I switched it to the fan jets that are already installed in the tucker along side the pencils and turned the flow down a little so saved some water as I decided to rinse on and go back later to check the results(which were pretty good but not perfect).

[Jonny 87]

Wow, 650 ltrs used up by 12.52pm.   What flow do you work on?
Do you usually finish all the tank by the end of the  day?
I must admit i use more water hot than I did cold, but Ive not drained the tank. Lol ive come close to doing so though. But I find if i work on a lower flow I dont keep the higher heat at the brush end.

What temp did you get the tank to in the end?

not sure as I have sealed the lid some time ago as it was leaking.

I have a digital thermometer on the way so I can drop the sensor in the tank. It was warm at best, could feel warm through the hose and in the van too.

I had the heater on from 5pm-7pm. then 1am-3am then 4am-6am then 7am-9am. in 650ltr.

Today I would normally use 450-500 ltr. by midday I could tell I had used more than normal and was close to home so I topped up just in-case. I reckon I have used 650ltr today altogether.

The first half of the day was worst, then I turned flow down to accommodate the heat and things levelled out.

I started the day with a14" with 4x2mm jets but wasn't satisfied with the flow so I switched to a tucker 12" on pencil jets but the pencils in the tucker must 1mm or something similar and the flow was way too aggressive. I switched it to the fan jets that are already installed in the tucker along side the pencils and turned the flow down a little so saved some water as I decided to rinse on and go back later to check the results(which were pretty good but not perfect).

In my experience I found that the first month of using hot, it can actually give you a little more spotting issues. Only the first month though. I put it down to hot water cleaning that bit better, perhaps taking more dirt out of a gap in the top
Frame that cold water wasn’t touching previously, which then ran down after you left and dried leaving spotting. It’s worth taking the extra time on your first clean with hot.

[dazmond]

Wow, 650 ltrs used up by 12.52pm.   What flow do you work on?
Do you usually finish all the tank by the end of the  day?
I must admit i use more water hot than I did cold, but Ive not drained the tank. Lol ive come close to doing so though. But I find if i work on a lower flow I dont keep the higher heat at the brush end.

What temp did you get the tank to in the end?

not sure as I have sealed the lid some time ago as it was leaking.

I have a digital thermometer on the way so I can drop the sensor in the tank. It was warm at best, could feel warm through the hose and in the van too.

I had the heater on from 5pm-7pm. then 1am-3am then 4am-6am then 7am-9am. in 650ltr.

Today I would normally use 450-500 ltr. by midday I could tell I had used more than normal and was close to home so I topped up just in-case. I reckon I have used 650ltr today altogether.

The first half of the day was worst, then I turned flow down to accommodate the heat and things levelled out.

I started the day with a14" with 4x2mm jets but wasn't satisfied with the flow so I switched to a tucker 12" on pencil jets but the pencils in the tucker must 1mm or something similar and the flow was way too aggressive. I switched it to the fan jets that are already installed in the tucker along side the pencils and turned the flow down a little so saved some water as I decided to rinse on and go back later to check the results(which were pretty good but not perfect).

In my experience I found that the first month of using hot, it can actually give you a little more spotting issues. Only the first month though. I put it down to hot water cleaning that bit better, perhaps taking more dirt out of a gap in the top
Frame that cold water wasn’t touching previously, which then ran down after you left and dried leaving spotting. It’s worth taking the extra time on your first clean with hot.

also very hot water can soften top rubber seals causing more run downs.

[AuRavelling79]

I also find that warm water after a spell of cold can soften the rubber in the reel connector (banjo) and can increase the chances of a leak.