# Truma Combi boiler - removal



## Carl_n_Flo (May 10, 2005)

Hi all,
Well, it had to happen!!! Full-timing sure puts extra strain on the systems of yer 'van. :roll: :roll: 

Our Truma Combi (gas/240v) water boiler has decided to throw a wobbly and only work on gas. Now, this happened a couple of weeks ago and I managed to get it going again on leccy - but I dont know how :? :? .

I thought that, maybe, the small glass fuse on the circuit board attached to the unit might have blown - but no....all is good here. But in my attempts to get at said fuse, I had to move other wires and covers - and so may have 'made' a dodgy connection, and hey presto, it was working again. No other fuses are blown.

SO - methinks I will have to remove the unit for a closer inspection.......BUT it is situated at the bottom of the wardrobe (below a false floor) behind the TRuma heater. Awkward or what!!!

Has anyone here actually removed one of these puppies???? What should I watch for? I am pretty handy with the tools, and feel that if I remove it myself, it may be cheaper to take the unit to a specialist to fix than to have them remove it and so lose the 'van for a while - remember, this is our home!!!!

Look forward to any advice before I get stuck in!!!!

Cheers
Carl


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## rayc (Jun 3, 2008)

The Truma Ultra-store has a self setting reset, if the heater has been switched on wthout water on 240v, then it will trip, isolate from mains, leave 5-10 mins, fill with water and retry.


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## Carl_n_Flo (May 10, 2005)

AAAHHHH - got me there..........don't know the model number at present (am at work in the office...) but it is an Ultrastore........ series 3???

There were no red 'reset' buttons that I could see - and the documentation didn't mention such an animal......

C


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## rayc (Jun 3, 2008)

Carl_n_Flo said:


> AAAHHHH - got me there..........don't know the model number at present (am at work in the office...) but it is an Ultrastore........ series 3???
> 
> There were no red 'reset' buttons that I could see - and the documentation didn't mention such an animal......
> 
> C


See the edit to my post.


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## Carl_n_Flo (May 10, 2005)

Now THAT is what we pay our subs for!!!!  

Cheers Ray - If that works it will save me a whole heap of trouble.............

Will try that one when I get 'home' this evening and update a little later....

Fingers crossed!!!!! :wink: :wink: 

Carl


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## clive1821 (Mar 27, 2010)

If you need some advice I have the c6000 series and had it out and replaced it... its an interesting job..... :roll:


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## Rapide561 (Oct 1, 2005)

*Truma*

Carl

I have had a lot of trouble with my Truma, more so on electric than gas.

On one occasion, it would work on 900 watt setting but not 1800 - the element had gone.

Same problem on another occasion.

Last problem - no electric at all - the glass fuse had gone.

Also, had some other 12v and fan problems.

Mine is a Combi 6E

Russell


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## AutoMax (Sep 23, 2008)

Hi, its not a 5 min job to remove, but quite straightforward. First shut of gas at regulator and at manifold under your sink. Then switch off 240v to van. Outside, remove exhaust vent and release 4 screws holding cover on, remove cover. Release 4 screws holding flue to body work. Next disconnect 240 supply from unit and also 12volt supply that runs from circuit board to control switch. Unscrew the gas pipe connection and then release the two water fittings. Finally it should be held down by 3 srews to the floor. Then pull firmly away from the bodywork towards the interior of the van and that should release the unit. 
You may need to remove the Truna ultraheat fan unit from the rear of the gas fire in order to have some room to lift it out.
I removed mine a week after I got the van new and its sitting in my shed, I should really get round to selling it, so if yours is u/s pm me with a reasonable offer.
Bob


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## Pudsey_Bear (Sep 25, 2008)

AutoMax said:


> I removed mine a week after I got the van new and its sitting in my shed, I should really get round to selling it, so if yours is u/s pm me with a reasonable offer.
> Bob


You knew someone would ask, so WHY? remove it are you a cold freak :lol: :lol:


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## Carl_n_Flo (May 10, 2005)

Kev_n_Liz said:


> AutoMax said:
> 
> 
> > I removed mine a week after I got the van new and its sitting in my shed, I should really get round to selling it, so if yours is u/s pm me with a reasonable offer.
> ...


#

He He He He - that made me chuckle!!!!!

I DID wonder why it would be removed - if there was nothing wrong with it......

Well - I have had the power to the unit turned off for 15 minutes so lets see if the self-reset works as Ray predicts......

If not - Bob - I will be in touch..........and thanks for the 'instruction manual' on getting the thing out!!!!

Carl


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## rayc (Jun 3, 2008)

Carl_n_Flo said:


> Well - I have had the power to the unit turned off for 15 minutes so lets see if the self-reset works as Ray predicts......
> 
> Carl


Come on Carl it has been an hour now. I won £10 on the lottery this week so I'm hoping my touch is returning. If all else fails come on down from Gillingham to Wimborne and get those guys at Autovan Services to sort it out.


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## AutoMax (Sep 23, 2008)

No, I dont love the cold that much. Just that I had a Webasto dual top fitted and it was unable to be integrated with the system. Seemed like a bit of a weight to lug round for the sake of it and removing it I gained a large storage space underneath the wardrobe. 
Good luck on getting it to work
Bob


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## Carl_n_Flo (May 10, 2005)

Sorry for the delay in replying - I have been brushing up on my French language skills..............by watching 'MESRINE' on DVD (Parts 1 & 2) - absolutely mesmerising!!!!!!

Anyroad.............

The top prize..........and Gold Star..........goes to.............

*RAY* ......for his insight, knowledge and expertise........

It WAS the trip!!!

Left the mains turned off for over half an hour - made sure the tank was full - and lo: the good Lord said 'let their be hot water' - and there WAS!!!

Boy, am I a happy bunny............

Thank you Ray - you save me a whole heap of work there!!!

And thank you too to Bob and the others for the advice and suggestions......all filed away in the old grey matter....

I remember now that the fresh water tank had run dry the other day just before we left for work and I didnt fill it back up until the evening. Of course, with the main switch being hidden at the back of the wardrobe, I didnt think to turn it off...........I will in future!!!

Once again - thank you all....

Carl


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## Pudsey_Bear (Sep 25, 2008)

Glad you're all sorted again Carl


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## rayc (Jun 3, 2008)

Carl_n_Flo said:


> I remember now that the fresh water tank had run dry the other day just before we left for work and I didnt fill it back up until the evening. Of course, with the main switch being hidden at the back of the wardrobe, I didnt think to turn it off...........I will in future!!!
> 
> Once again - thank you all....
> 
> Carl


Carl, Can you confirm that everything was working fine and then the fresh water supply run out whilst the boiler was switched on. This has apparently cause the overheat trip to operate?

If so it houldn't of as there should be a non return valve in the boiler cold water supply thus ensuring it has water in it unless it is drained down.

Ray


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## Carl_n_Flo (May 10, 2005)

Hmmm..... Interesting...

We definitely were out of water in the fresh tank that day, and the power was left on. Didnt know about the non-return valve though.

Could it be possible that the valve isnt working? But then - the boiler could not be emptied via the water pump as that only pumps cold water. To get hot water, the pump pushes cold water into the tank to displace the hot......therefore if the fresh tank pumps dry, there is no more cold water to push out the hot....therefore there should always be water in the tank..............Ray, what you say makes sense..... If the n/r valve is faulty, where would the boiler water drain back to? it can only drain into the feed pipe as far as the pump, and that is higher than the boiler so it cannot go far. And the dump valve isnt leaking as I would have noticed that.

The mystery deepens..............................

Still working at the moment though..
Carl


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## rayc (Jun 3, 2008)

Carl_n_Flo said:


> Hmmm..... Interesting...
> 
> We definitely were out of water in the fresh tank that day, and the power was left on. Didnt know about the non-return valve though.
> 
> ...


Carl, "Still working at the moment though" and that's what matters.

The movement of water is strange and if I had to guess I would say that the cold feed to the boiler and the feed to the cold taps is common. In the final seconds before the freshwater tank run dry then the pump pushed water to the cold taps and in the process pulled water back from the boiler. That is why there should be a non return valve in the boiler input.
That could all be a load of rubbish of course and we will never know. If the water tank runs dry again could you check, when you have refilled it, that the boiler has lost water or not by opening a hot tap and seeing if you get air or water. If water straight away then it didn't drain.
There is a non return valve on the ultra store, items 46 or 47 on the attached schematic and appears to be close to the drain valve in, I presume, the boiler cold feed hose before the drain down valve [ i.e. in the feed from the fresh water tank before the drain valve].
http://www.campingrus.co.uk/Truma-Ultrastore-Spare-Parts-Schematic

Ray


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## Carl_n_Flo (May 10, 2005)

Thanks for the insights Ray - usually when the fresh tank runs dry, we do get a lot of air and spurting from the hot side of the taps when we open them up again after re-filling the fresh tank. Same with the cold side of the tap. That is why I assumed that the boiler had also been emptied.

I seem to remember somewhere something about ensuring that the lines to the taps being primed after re-filling an empty fresh tank, to prevent the pump from constantly running - and to turn the taps to 'hot' and run them to purge air from the pipes (and I assume the boiler) to prevent damage to the boiler. I will check the 'van handbook now in a minute to see where this was written.

Back soon...........
C


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