# Truma heater (hymer 544) Water problem......



## enrohtwac (Oct 7, 2009)

Anyone have any ideas, yesterday my hot and cold water worked fine. Today when i turn on the tap (either tap) there is water falling from under the van. Its not the dump valve as this is closed. The water is coming out of the expansion pipe at the top of the boiler. The boiler is off yet it is as if no water can get in to the boiler so it just comes out of the expansion pipe. a very slow trickle comes out of the tap....

is it an air lock? how can i check further? 

any suggestions welcome, we are in south of france at the moment. 

dont really know whats going on here... the boiler is brand new fitted 3 months ago. 

thanks 


james


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## davesport (Nov 12, 2006)

James do you know which model your boiler is ?

D.


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## davesport (Nov 12, 2006)

Further to my last post. There's an over-pressure valve incorporated into the HW outlet at the top of the cylinder. From photo's I took at the NEC show it looks like a grey plastic tee piece emerging from the side of the boiler. Your domestic HW comes out one side of the tee & the dump comes out of the other. The dump is normally directed down & out of the vehicle. From memory this opens to prevent the HW cylinder being exposed to pressures in excess of its design.

Hazarding a guess, if the over-pressure Vv has gone south it could give the symptoms your experiencing.

Hope you get sorted, D.


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## Pugwash (Jun 12, 2005)

Agree with Dave - sounds like the pressure valve on the outlet of the cylinder. They don't really look like a valve, more like a tee-piece that's unlikely to have anything inside. When the valve fails it gives the result you describe. I don't think you can do anything with it except buy a new one.

Pugwash.


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## enrohtwac (Oct 7, 2009)

Hi Thanks for help both of you. 

Model is c4002. I looked at the instruction manual and the problem is on the hot water connection outlet. I can see the 't' piece you are talking about. do you reckon this is a piece i can buy on its own? 

why would this affect the cold water also? 

you have been really helpfull thanks. 

james


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## Pugwash (Jun 12, 2005)

Hi James,

Yes you can buy the Tee connection separately. There are more than one type though - the connections differ. The colour depicts which one it is. (It's probably either red or grey?). Take note of this when you go to buy one. (Get the full serial number off the sticker on the unit)

The link below is a 1.3Mb file so be careful if you're paying for internet access by quantity, but it shows the heater in diagrammatic form. Page 3, drawing K, Part 42 is probably the one you're having trouble with. (This is not the "part number" as such but simply the identifier on the drawing).

http://www.truma.com/_anweisungen/Truma-Katalog/pdf_verzeichnis/30_000/34000_94900.pdf

It's probably affecting the cold water because the pump can't keep up with the amount of water that's going out of the hot water exhaust. I think once you've fixed the hot water problem the cold will be OK too.

If you can't get the part you may be able to get the cold water going again by shutting off the supply to the Truma heater. If there's no valve or tap remove the cold supply pipe and block it off (a bolt in the end with a jubilee clip round perhaps?) This should at least get the cold water going again.

Good luck - let us know how you get on.

Regards 
Pugwash


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## davesport (Nov 12, 2006)

The reason it's affecting the cold side as well, if your plumbing's anything like mine. Is that whenever you open one of the taps the pump's activated & pumps at full pressure regardless of demand. IE on or off. So when you open the cold tap the pump sends the water via the path of least resistance. In your case to the HW cylinder & straight out the allegedly defective over-pressure Vv.

So you'll have little or no pressure uintil it's fixed.

D.


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## enrohtwac (Oct 7, 2009)

Pugwash, 

that looke like the bit. Mine is red. There is a motorhome garage near where i am at the moment. ill take it today. I havent used the heating since this started, not sure is you can use the heater with no water in the tank or not. 

My boiler was installed 3 months ago in ilfrecombe, devon by woolacotte marine. I dont appear to have one of those automatic dump valves for frost protection. i only have a manual one. do you reckon the automatic one comes as part of the new boiler? if so they owe me one.

I am on my way to spain for some sun (ish) and dont fancy turning round though... 

top support, help and advice thanks 

will defo let you know how i get on. 

james.


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## enrohtwac (Oct 7, 2009)

D. 

Great thanks. It makes sense now. Yep i have one pump in the tank which is either on or off. not sure if its the orig part fitted by hymer or not. 

thanks again for your help. 

James.


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## rayc (Jun 3, 2008)

As a temporary measure clamp the clear pipe at the pressure releif valve. This will enable you to fill the boiler and use it [ plus use the cold water]. Obviously keep and eye on it in case of overpressure but if you are aware of it you can open a tap occasionally whilst it is heating if you are worried that it may overpressure.


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## Pugwash (Jun 12, 2005)

Hi James,

Yes you can use the space heating regardless of the water not being in
the tank.

If you can't get a replacement valve easily email Marc DeVito in Germany. He's the Truma tech guy and will be able to tell you the nearest place to get one.

[email protected]

Regards
Pugwash


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## enrohtwac (Oct 7, 2009)

cheers ray c.


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## enrohtwac (Oct 7, 2009)

Cheers Rayc. 

James


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## enrohtwac (Oct 7, 2009)

Thanks to everyone for their help, in particular Pugwash. 

Bought a new 't' piece today and all is well. 

top stuff, now off to spain.... heading in to barcelona and then down to mercia etc... any good sites? 

thanks again. 

James.


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## Pugwash (Jun 12, 2005)

Pleased to hear it's fixed.

Can't advise on campsites down that way - it's a bit off my patch. I believe there' a good one on the waterfront at Barcelona but we haven't been yet - hoping to get there ourselves this summer. 

Have a look in the campsite database on here, or on the Spain forum.

Have a great trip.

Regards,
Pugwash.


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