[Nathanael Jones]

I'm not sure if that's the name Alex will be giving the finished product,.. but I do like the sound of it!!!

I removed the thermostatic valve entirely today,... no need for a bypass anymore, the heater comes on using my usual flow rate now!

It was a good idea while it lasted,.. but I'd no longer recommend the thermostatic valve,... So,... HOT WFP just got even cheaper!!!

 

[NWH]

The system i`m getting has a thermostat on it,what happens now you`ve taken it off.How are you finding cleaning with hot water Nat.

[Nathanael Jones]

I can still adjust the temp using the heater controls,.. the thermostatic valve was more of a fail-safe/precaution than anything.
I'm finding hot wfp brilliant. I'm still not even half way through the first bottle of gas,.. so the running costs are incredibly low. I do find that hot water is making my hands crack a little,... time to get out the barrier cream again!

[steven ainger]

so what flow rate do you use nat,

[Nathanael Jones]

I'd be about a litre and a half a minute,... maybe a little less. I'll get out the measuring jug in the morning and check! I have the dial of the flowmaster set to 5.5 or 6 with 2X 2mm pencil jets.

[steven ainger]

i think i may have a go myself soon, is there any alternatives to your heater, to your knowledge

[Nathanael Jones]

There are a few on the market (search for "tankless" on ebay!). The majority of them are unvented,.. so there is no attachment to allow a flue connection on top,.. you just have to leave the van doors open.

There are Morco heaters designed for static caravans (I think this is what Mr Sol has) but they need a higher flow rate (Fixed with a bypass back to the main tank) and cost a bit more.

Looking at how simply made the body for my heater is, I'm sure fabricating a hood to go over the top of one of the unvented (smaller) heaters would be a simple job,.. but as always, make sure there is plenty of ventilation in the van.

I really liked this one (the minimum flow rate would keep even Jeff Brimble happy!):
http://cgi.ebay.ie/Portable-Tankless-Hot-Water-Heater-Liquid-Propane_W0QQitemZ290214786597QQihZ019QQcategoryZ42240QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
But I was kinda fixated on getting one with a vent connection, so went for the arazibo one instead.

[matt]

the venting should be a issue though

if you have a full bulkhead in your van and you fit 2 roof vents, that should keep a flow of air

[Nathanael Jones]

the venting should be a issue though

if you have a full bulkhead in your van and you fit 2 roof vents, that should keep a flow of air

If there isn't a flue direct to one of the vents, I'd recommend a 12V powered extractor fan to help expel the fumes.

All these heaters have an oxygen sensor, so if there's a build up of fumes the heater will turn off,... not something you want in the middle of a big first clean!

[Nathanael Jones]

I'd be about a litre and a half a minute,... maybe a little less. I'll get out the measuring jug in the morning and check! I have the dial of the flowmaster set to 5.5 or 6 with 2X 2mm pencil jets.

I just measured my flow rate (A bucket, stopwatch and measuring jug!) and got a bit of a shock,... almost 2 1/2 litres a minute!!!! Maybe I do still need that bypass setup after all!!
That's the flow I was using cold btw,... I just never realised it was so high!

 

[Village Gleam]

That flow rate is more realistic. a picture of the bypass required is in my earlier post. None of these heaters including the Marizboa  actually require a flue.

Murco and Rinnai heaters have a CE mark. I have a Marizboa and a Rinnai, the Rinnai has a higher power output and flow, hence the need for a bypass. The Marizboa I found to be amost perfectly balanced unaided.

[Village Gleam]

I'm looking for a ratchet Matt, I'm having one made but if they are available anywhere I'd get one, if not I might offer screw fix first dibs and make a few bob. Do you know where to find one?

[Wayne Thomas]

I'd be about a litre and a half a minute,... maybe a little less. I'll get out the measuring jug in the morning and check! I have the dial of the flowmaster set to 5.5 or 6 with 2X 2mm pencil jets.

I just measured my flow rate (A bucket, stopwatch and measuring jug!) and got a bit of a shock,... almost 2 1/2 litres a minute!!!! Maybe I do still need that bypass setup after all!!
That's the flow I was using cold btw,... I just never realised it was so high!

 

Funny how the hot water (when it's sheeting easily and thinly), looks like you are using less water. I'm not surprised at your measured results, lol.

[NWH]

Wayne how hot did you say your water gets.

[Wayne Thomas]

Wayne how hot did you say your water gets.

60 degrees at hosereel.

[Dave Turley]

hi guys.

wayne, i've just found this topic and wanted to say well done and thanks very much.

I know it's a bit sad but I just couldn't read it fast enough.

this is real exiting stuff and I think i'm gonna order a heater very soon... today maybe!

thanks again,

dave     

[Nathanael Jones]

Dave,.. I've now found a heater that would be better suited to WFP needs. It's a lower BTU rating,.. but the heater I have is on minimum heat most of the time anyway.
The main benefit is that it works at a much lower flow rate,.. the heater I have needs either a bypass valve or a flow rate of over 2 litres a minute to work reliably.
The other disadvantage of this new heater I've found is that its "Unvented",.. eg. there's nowhere to attach an exhaust flue. After seeing the Arazibo heater with the flue, I can see that it would be a very simple job to get a hood fabricated to fit over the top of the heater and connect to a flue.

http://cgi.ebay.ie/Portable-Tankless-Hot-Water-Heater-Liquid-Propane_W0QQitemZ290216716734QQihZ019QQcategoryZ42240QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Nathanael Jones]

There are 2 things that have been bugging me since I've gone hot:

1. The high flow rate or awkward bypass setup required to run the heater
2. The heater has oxygen sensors, overheat sensors, flame out sensors etc. If one decides to kick in (Normally the oxygen sensor in the back of a van) then you physically have to go all the way back to the van to reset the heater.

I think I've got this sorted though!

I took apart the heater yesterday and saw that the flow switch is a mechanical lever that releases a micro switch when the flow pushes the lever enough. I can replace that switch with a simple 12V relay that is operated from the main WFP pump. When the pump is running and there is a current, the relay will close and activate the heater, regardless of the flow rate.
Also I'll have the heater main on/off switch wired into the relay,.. so every time the pump stops, the heater will reset. No need to walk all the way back to the van!

The heater safety features will still be in place,.. the over temp sensor being the most important IMO for general use.

Here's the relay I'm going to try:
http://cgi.ebay.ie/ws/eBayISAPI.dll?ViewItem&rd=1&item=120244458312&ssPageName=STRK:MEWN:IT&ih=002

You'd prob get something similar from Maplins!

[Nathanael Jones]

Update:

The original relay works,.. but requires the flowmaster to be turned up higher than I'd like to provide enough voltage to activate it, so I've just ordered one of these:
cgi.ebay.ie/ws/eBayISAPI.dll?ViewItem&rd=1&item=260192728598&ssPageName=STRK:MEWN:IT&ih=016

It's 6 volt,.. so it should switch the heater on with a very low flow rate.

Here's a wiring diagram courtesy of Jeff on the training academy:

[Nathanael Jones]

The new relay arrived today,.. and since its raining I managed to get it installed straight away! This is the item:
h.t.t.p://cgi.ebay.ie/ws/eBayISAPI.dll?ViewItem&rd=1&item=260192728598&ssPageNam...

Its the 6 volt one, NOT the 12 volt.

Its installed and working PERFECTLY! 

The heater starts as soon as the flowmaster clicks, on a very minimal flow! It switches off as soon as the pump does,.. and even though its only 6 volt it doesn't even get warm when the pump is running at full speed (I just tested it for 10 mins constant).

I reckon this is the solution,.. the final word in heater control for WFP!