[Nathanael Jones]

One final (I hope!) improvement to my setup is an auxiliary pressure switch. This switches off the heater much sooner after the flow stops (The pressure only has to build up to 30 psi in the hose/reel) and allows me to use an even lower flow rate without the overheat sensor kicking in.

Previously the heater ran when the pump did,.. so when I stopped the flow at the pole the pump would continue to run for quite a long time building up 100psi in the hose and reel,.. and during this time the boiler would overheat and cut out.

Here's a new wiring diagram:

[macmac]

Nathanael

This is one excellent topic & posts, you've done a superb job with your hot set up & I for one, am very gratefull for you sharing your knowlage & experience on this subject. I sit here astonished at what a superb solution this is for hot wfp & how (reletively) simple & cheap it is.

If i were a supplier of hot systems i'd be quaking in my boots!!!!

Thanks again & please continue to keep us up to date.

Regards

Tony

[windowcleaninginessex.co.uk]

Just a thought will this affect you van insurance,
Darren

[edd]

hi NJ just caught the end of this so here i go my thermopure has a pipe from the heater straight
into the tank so it heats the tank water AND a  t piece with a tap so i can vary the amount of flow
to my pole so to speak
 so its heating the tank when on the move by adjusting the tap and when we stop we can have it
 all to the hose but we always leave it open just a fraction so some water goes back to the tank
as not to build up a back pressure hope this helps EDD sorry to but in

[Nathanael Jones]

Thanks for the comments Macmac!

Darren,.. it depends on your insurer, my insurer wasn't bothered and didn't charge me any extra, but ALWAYS check first!

Edd,.. I remember the pic you posted of your setup previously, and it looks very nice! I've also got a bypass valve fitted, but so far I've only used it to heat the tank on frosty evenings. My heater has a 20 minute safety cutout, so starting and stopping the flow every now and then (between windows etc) is essential, and it doesn't work well with the bypass valve open more than a fraction.

[Clive McDonald]

I'm quite impressed too Nathaniel, what macmac said is true. It's been quite a long thread and in places I have contradicted you, and you have proven me wrong.

However i think your solution to an easy problem is way too complicated. Anyone who wants to go hot should follow my lead and not try to modify manufacturers systems.

My system is simple. My system works.(i'm not trying to one up you, it's a bought in heater and a simple bypass, the cleveness in my system is all other peoples)

As regards the other topic(electric reel)- it's the same- keep it simple stupid, but in a way I am looking forward to what you are going to come up with.

If you remember instead of getting on with it you faffed and fannyed about with hot- and I told you to jump in-. The reels no different, not matter how you do it,   it is a massive, yes massive, advance.

[Wayne Thomas]

I've found that if I pre heat my water tank I start getting problems with the pump so I only use my water hot straight from the heater. Come the winter I think I won't bother pre heating my water tank, I'll just use a mixer valve so I can regulate the heat after the heater if it's too cold outside.

[Clive McDonald]

As mentioned my problems have been varistream related. The bypass back to tank wasn't put in to heat it, although it could do this.

Funnily enought I think it was you Wayne who told me to keep it simple stupid. And when I follow that advice my stuff works. I took the di off the van for instance and told Nathaniel about this but he still had to find out for himself.....

With on demand systems there is no need for hot water to go through the pump.

[Nathanael Jones]

A quick update:

An easier and more reliable way of controlling the heater switching on and off is an in-line flow switch. It took me ages to fins a supplier of these for a price that i'd consider reasonable (most I found cost more than the heater!). The GEMS switches are good,.. I have the 1 litre per minute one, which I find a little too sensitive, so I'd recommend the 2L per min switch,

www.radionics.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&Nr=AND(avl%3aie%2csearchDiscon_ie%3aN)&N=4294879990+4294955387&Ns=I18NPrc1_ie&Nso=0#resultArrow

[Clive McDonald]

Could you explain more fully. You have bypassed the heaters internal control and now use this one instead?

[Nathanael Jones]

Could you explain more fully. You have bypassed the heaters internal control and now use this one instead?

Exactly,.. the inbuilt flow switch requires nearly 3 litres a min to switch on. I've modified my system to use this external switch instead, and also installed a relay that switches the unit off when the pump isn't running,... a additional  fail safe feature to prevent the heater running without water flowing.