Water heater tank installation advice please....

Post by **lewd lude lover** » Thu Dec 04, 2014 12:44 pm

Hey guys, anyone with a little experience with plumbing and pipes and water heaters could seriously help me out here.

I need to know if what I have planned is feasable, safe, advisable and doable....

The mission:

Install an AC electric water heating tank into my RV for the shower.

The question:

Can I fit what is basically a house water heater that would want to run off mains water pressure into a pumped water system. The pump will be a 40psi/2.75bar 17lpm on demand marine pump with an accumulator to keep the pressure stable.
The seller is not willing to advise as its outside the normal application. He 'has some worries about the pumped water system'

As I understand it mains water pressure is normally between 2.5 and 4.5 bar and is pumped from a treatment works to your home. I cant see that there is any difference in my application than the fact its in miniature and in a lorry.

This is the tank I want It is horizontal as I want it under the floor outside to save internal space.
I have an electrical junction/fusebox in the RV and would intend to run the tank off a properly mcb/rcb protected circuit.

All pipe fittings are standard house stuff.

Can anyone see how I might blow up? Any advice appreciated.

As would links to cheaper options/advice as to what ''safety kit'' I need and ideas to achieve the same result withother methods.

I dont want a gas boiler but there is an option of 24v water heaters but i am in doubt that the are for pressurised systems.

Thanks

bennyboy · Post by **bennyboy** » Thu Dec 04, 2014 12:52 pm

This may be missing something/stating the obvious/no bloody help at all

, but could you fit a small domestic electric shower unit, that just heats the water itself?

Post by **lewd lude lover** » Thu Dec 04, 2014 1:29 pm

I could but so far the current draw is too big. they pull 8-12kwh and need serious wiring and earthing etc. I have to remember that I will either be hooked up to a 13amp plug into the RV or on my 4.5k generator. As such a water tank at 2k rather than a power shower, in line water heater, instant boiler offers a safe current draw from a normal plug.

My first idea was a MIRA but I cant find anything that looks like it'll be safe to run on 13a.

Also I can hook up the hot water tap in the sink with a tank but not a shower.

The seller included a really high quality gas boiler to install but it needs a hole cut in the roof, a gas fitter and it takes up a really big space in the van. They also produce condensation which is never good in an enclosed space. This will be getting sold to provide the cash for the water tank. He set it up so he could sit on the side of a mountain for a month. I'll never be that far form AC power and the tank under the lorry outside, suitably insulated from frost, gives back loads of space and makes it all easy..

Unless it's likely to blow the back end off the lorry one morning

Thing is all the safety valves etc would alrady vent to outside and would be covered by cowling.

I just need to know if my intuition is sound. Or if I am making a problem..

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Dec 04, 2014 1:37 pm

I think domestic water pressure is a lot lower than 2bar;

http://www.ofwat.gov.uk/consumerissues/ ... _gss08.pdf
0.7bar is the standard water pressure they must provide according to this.

Marine pumped systems run at higher pressure to counteract the lower flow rate I think (smaller pipes etc.) as well as the obvious reduced head (

obviously!

)

Have you looked at marine water heaters that are designed for pumped systems? I know the voltage would be different (12v or 24v and you want a mains system) but you could still use that, via a voltage regulator instead.

It would probably be advisable to use a Marine heater rather than a domestic one anyway, as it would also cope better with the damp/larger variation in ambient temperature and vibration that your truck will get in comparison to a domestic heater in a domestic dwelling?

You can also get marine water heaters that run directly off diesel, as another alternative, so you weren't bound by having a mains supply (though I don't know which would actually work out cheaper on running costs?) This would also get round your problem of total electrical load from the supply?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Dec 04, 2014 1:49 pm

lewd lude lover wrote:The seller included a really high quality gas boiler to install but it needs a gas fitter

Only if you're bothered about it being certificated. Nothing to stop you installing it yourself if you're confident in your abilities and follow the installation guide and relevant rules/regs.
Is it a Calor gas boiler, I take it?

I installed my home condensing boiler myself.
Technically illegal because I don't hold a bit of paper saying I'm 'gas safe' registered, but a) I'm not selling my house, b) considering I'm a qualified engineer and spent 2 1/2 years as an engineer working in a process using all sorts of gases, I'm reasonably confident I could demonstrate adequate competency if it became necessary for any other means!!!
When the gas board came round to swap the meter recently, they certainly didn't raise any concerns with it, anyway! (and it's in the same room and they had to restart the boiler after

)

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Dec 04, 2014 1:58 pm

Mudgey sells some water (and air!) heaters that might be suitable?
http://www.t7design.co.uk/index.php?mai ... d58e0646a9

Might be a worth a chat with him?

Post by **lewd lude lover** » Thu Dec 04, 2014 2:30 pm

cheers wurly thats cracking advice all round.

The .7bar is a minimun static head pressure or they get into trouble with ofwat, as I understand it. anything under 1.5 bar and showers start to be abit weak/shutdown. The current 10.6lpm 30psi pump is no where near normal tap pressure thats for sure.

Diesel heaters and calorifiers have been looked at and discarded so far as looking like a fricking nightmare to fit. They are still on the cards but no looking good due to the pipework and gubbins needed.

I agree the vibration 'might' be an issue but with proper mounting this should be taken care of, big rubber bushes etc. All the onboard marine or motorhome systems i have seen so far are piddly and wont do the job I want (missis has lots of hair on her head and needs to wash it daily

). The gas boiler is a MORCO LPG 11l boiler. The seller fitted a full LPG autogas system for the boiler and the cooker. I just want to use it for the cooker though. Seems to basically be the macdaddy of onboard boilers but it comes down to internal space and use. It is just too big and involves too much drokking about in my view, at the moment, to fit it. I can see how I can do this tank fit in a day. the gas would need a proper gas bloke to fit it. I am not confident in any way that I could do a ''proper' job on that and leaky gas in a sealed box sounds like blue lips and no soul.....

24v water heating systems that I can find dont work under pressure so I am having issue there. I would be happy with a 300w 24v tank run off the leasure batteries and charged via the solar panel but I just cant find anything thats is used with pressurised systems.

This is all at the start of the process of course, I just wanted to pick the brains of the most effective knowledge base that I have available

Post by **lewd lude lover** » Thu Dec 04, 2014 2:32 pm

This fitted into a sealed tank would bloody great but I cant find a tank to put it in. they all seem to be thin copper jobs, not Stainless and hardcore.

Post by **lewd lude lover** » Thu Dec 04, 2014 2:35 pm

oh, the seller came back with the fact that he has supplied mobile dog groomer vans that run off the customers house supply to very good effect. I think the mobile aspect should be ok.

Post by **lewd lude lover** » Thu Dec 04, 2014 2:50 pm

http://www.ebay.co.uk/itm/MORCO-D61E-Ga ... 2343fbd489

this is the same boiler that I have here but I just cant see it fitting in the space as i want it.