Truma Water Heater Problems

Truma Water Heater Problems!

Motorhome life has been far from smooth recently for a number of reasons. In August my Truma Water Heater developed a leak that is still causing me problems today.

Truma Water Heater Problems

I first noticed the problem when the carpet near the boiler door seemed to be wet. On taking a closer look I noticed that water was dripping from the hot water outlet connection. The small plastic part is I believe referred to as a pressure relief value. A call to Truma UK revealed that the part had changed in the late 90’s and I would need to give them the boiler serial number. Naturally, mine was the older boiler and the part number I needed was 34000-55600 which had been phased out. The newer part number for the newer boiler was 34150-01.

I asked Truma what I was supposed to do as it seemed totally unfair to have to buy a new boiler costing hundreds of pounds just because a small piece of plastic had failed! The advice given was pathetic, apparently I should visit a plumbers merchants and get them to try and make something up. Shocked at the poor customer service offered by Truma UK I decided to email Truma Germany but their reply, whilst apologetic was equally unhelpful.

Taking the old part to a plumbers merchant they tried to replicate the fittings in metal and whilst it did fit, neither they or I truly understood the significance of the thinner pipe that points up which I now know to be the breather tube. If you blow into this Truma Water Heater part you will discover that most air rushes down the larger pipe and the thinner pipe has some valve built inside that only opens in the event that pressure builds up too much inside the boiler, a safety feature.  The plumbers merchant did not know this and failed to replicate this valve meaning that when I activated a tap water would simply head up and out of the overflow through the pipe that exited the vehicle underneath.

Truma Water Heater

After this initial failure I decided to buy the newer part to see up close how they differed. Whilst the older part is a screw type the newer is considered to be a push type. However if you discard some of the parts from the new part you effectively have something that looks quite similar to the old part. At least the thread that connects to the boiler is the same and the existing hoses would also fit the hot water and overflow pipes. With the new part fitted however the pipes barely cleared the boiler casing so I could not connect hot water outlet or overflow pipes. A further trip to a plumbers merchant and after buying a 1/2 inch BSP male to female extender and applying some plumbers paste and tape the new part was fitted. As luck would have it once it was screwed tight the pipes lined up perfectly.

This repair seemed to have worked but some weeks later water began to leak again. This time I purchased two parts for the Truma water heater and set about trying again. Until now it seemed to have worked but today again it began leaking. I could try and fit the final spare part I ordered in the hope I will get a few more months from it but I think I will speak to a relative who is a plumber to see if there is any other solution. I certainly don’t see why I should buy a new Truma water heater when the actual boiler works fine. Shame on you Truma for not supporting your water heaters for longer!


  1. Having just read your unfortunate experiences with your Truma water heater, I am currently filled with unbridled joy (I don’t think).Whilst on holiday mt water heater also began to leak from the same place, as yet I haven’t looked at it to assess repair. If I have any revalations while repairing I will write here as to anything that might be useful to pass on

  2. Hi Bert,

    Sorry to hear about your problems. If you have the same type of boiler as me (the older type) you will find that plastic part impossible to find and Truma will not be very helpful. Since the boiler itself was working fine I did not want to spend money on a new one and have since managed to fix the issue. The newer part can actually be adapated to fit. I have a relative who is a plumber and he gave me some parts that allowed me to use the newer part. It’s some extra cabling and might not look as attractive but it does the job perfectly and does not leak and that’s all I’m concerned about. It was also a cheap fix which you cannot complain about in the current economic climate.

    If you want to know more let me know. I could photograph the boiler and tell you what parts he gave me to adapt it.


  3. I tried to fill my truma water container after not having used it for a while and the water is just running straight out. Can anyone help?

  4. Hi Tony,

    Did you manage to sort out the problem? When you say ‘running straight out’ do you mean out of the overflow and under the vehicle? It’s hard to say without seeing your vehicle but if you have the same boiler as me it might be the part I had to replace.

    Good luck

  5. If Tonys is the same Truma water heater that you (Gary) appear to be talking about, then its possible that the ‘Frost’ safety valve has operated (this can happen either thru a drop in temperature, through driving over particularly rough terrain, or because the power to it has been disconnected – there is a switch adjacent to the safety valve which removes power to it when working on it). This valve empties the heater through a drain pipe through the van floor. It can be reset by a push button next to the valve, providing there is power to the valve. On a different point Gary, my experience with Truma was similar to yours. I demounted the system and took it to a Truma agent for repair which he managed o do after sometime, but it came back saying they couldnt guarantee the repair and further repairs would not be possible due to lack of spares. Working it out for usage ( I am not a fulltimer and this is a 1995 van which I have owned since 2000) , and taking into account the fact that often I will boil a kettle rather than wait for the full boiler to heat up when requiring water, and will augment the space heating element of the boiler when hooked upto mains power, the boiler has probably only been used for 432 hours or 18 full days since new! Trumas Customer Loyalty sucks! On a further note I fixed the 5th gear problem for £350 – I left a comment.

  6. I broke the elbow from the top outlet of my C3400 boiler. No parts available, of course but I found this thread and was inspired to know that the later hot water elbow could be contrived, one way or another, to fit the older C3400 boiler.
    I purchased a 34150-01, and found one in grey with the connections at 180 degrees. Most seem to be red with connections at 90 degrees.
    I kept the new elbow intact without dissassembly and made up a 1/2″ BSP to 10mm pipe reducer. The new 3415-01 elbow then clamped straight onto the 10mm pipe. Cost of brasswork about £5 and 15 mins work. Image available if required.

  7. Hi Andy,

    Thanks for the comment. I’ve had lots of people contact me about these outlets for boilers. It seems Truma don’t care when the part fails but the newer style part can often be adapted to work with the older boilers. If you want to submit a photo please do as it might help others with a similar system to yours.

    Thanks for the comment
    The Motorhome Vagabond

  8. Have just used my 2009 Arapoho since the Winter break. Refilled the water system and found that the Truma water heater will now not heat up on the electric function, only by using it on gas will give me hot water. No fuses are blown so am puzzled what the fault could be??

  9. I’ll leave your comment in case someone can assist but my boiler was gas only so can’t really help myself. Hope you find the problem.

    All the best
    The Motorhome Vagabond

  10. Water is dripping out of the breather hose in my Winnabago from a Truma boiler

  11. Richard Pearson….I too had my 240v heater fail on me. It is a separate heating element held in place in the bottom of the boiler with 2 screws. I thought the element itself had gone as it was open circuit when measured between Live and Neutral with an ohmmeter. But I was puzzled as to how it could turn off as it is supplied with just the switched mains so having removed the electric heater I decided to chisel out all of the resin where the cable goes in. I found a thermostat and a thermal fuse and exposed the ends of the element which measured OK. I rebuilt it all with a 60 degree thermostat and 125 degree (I think) thermal fuse and refilled it all with black high temperature silicone. Voila…mains hot water again. Bit fiddly and not recommended for someone not competant but it is doable. I am comfortable with what I have done. I was seriously considering a new boiler. Shame Truma don’t just have spares. Pretty pathetic really.

  12. Just had the same problem in my Pilote. After reading your blog, I ordered the new 34150-01 fitting from leisureshopdirect. I then took both old and new bits to a small hydraulic dealer.
    he took both pieces into his back room, and came out with 1. a 1/2 inch to 1/4 inch reducing bush, and 2, a 1/4inch to 10mm push fitting, and a piece of 10mm plastic pipe. Works perfect, total cost £17.25. Images available.
    Thanks for the initial advice. Mike.

  13. Hi Mike,

    Great news that you were able to fix this so cheaply. I get asked about this all the time and it’s hard to describe verbally and as I don’t have photos or the vehicle anymore I’m not always able to assist. If you don’t object maybe people reading this post could contact you for images?


  14. Had the same trouble with my C6000 over the years. I did take a new C6002 vent valve apart and fitted the little ball float in the old unit but can’t remember how. but it worked up until Feb. 2016 now its gone again after 5 years. I have just fitted a in line windscreen wash none return valve (8mm) the wrong way round so if their is no pressure the valve stays open but when you turn on the hot tap the valve closes. seems to work. How long for I don’t know

  15. Hi,

    Yes it seems with motorhomes there are always some little jobs to do. My fix for the Truma seemed to last until I sold the motorhome. I have not purchased another motorhome since but ironically I’m currently travelling with a friend in his motorhome for two weeks in Europe.

    All the best
    The Motorhome Vagabond

  16. This valve has finally failed for me too. For about a year it has made damp patches on the road. Now every time you turn a tap on, instead of water coming out of the tap, water runs out of the Truma vent pipe. I should have fixed it a year ago!

    Mine is the later version, so 34150-01 is the right bit. The old one was straight and grey, looks like replacements are 90 degree and red, but that won’t matter. Shame they are about £10 plus £4 postage for an item weighing about ten grammes. I’ll try to find one locally.

    Looking at the failed one after taking it off, there doesn’t seem to be any sort of pressure valve or one-way valve in there at all. I guess that whatever was there has disintegrated and flushed out or perhaps I dropped it when I took the elbow off.

  17. Anyone needing help or spares for a Truma Combi 3400 0r 6002 Boiler can contact me on 07887705480. There seems to be lots of people needing help and maybe they would be grateful for the chance.

  18. We had a Truma combo in an auto trail that stopped working whilst on holiday in August, Motorhome was 4 yrs old and had done just 6000 miles. Could not get anybody interested In looking at it until the end of the season, the Truma appointed agent for my area(Sittingbourne )was voicemail only and did,nt even return my call, gave up on it in the end and part exchanged for a new Bailey autograph which has an alde system, much easier to understand than the twin control Truma but as to reliability, time will tell

  19. Yes I hear good things about the Alde system. My Truma system was basic but actually very reliable. My issue with them is that they expect you to replace the whole boiler at huge expense for a small plastic part that they don’t stock anymore. Naturally I found a way to adapt another part but customer service like this does make you think about where you spend your money in future.

    The Motorhome Vagabond

  20. I wonder if anyone could help me with a problem on a Truma 4E combi. Over the last week it seems to have decided to have a mind of its own. When we first connected we had a fault in the LCD screen saying wrong connectivity with the red light flashing, turned the power off and left it and then restarted the system and it all started up ok. Later in the holiday tried to put the heating on and the room temperature showed 30 degrees when it was only 19 degree in the van so couldn’t start he heating and the LCD panel wouldn’t allow me to raise the temp above 30 degrees. Once again turned the power off and the room temperature dropped to 19 degrees and the heating worked all ok again. then in the middle of the night with no heating working only the hot water the blown air heating came on full speed like a jet engine for no reason. Does anyone have any ideas what the problem maybe
    Many Thanks David

  21. Hi, I am currently on a European tour of 13 weeks. 3 weeks in my Truma heater is playing up. It is constantly over heating even with the temperature right down and the pump is then refilling the tank which in turn empties the water barrel. I can only assume that either the thermostat or a pressure valve or both are faulty. I don’t know where they are and where to get the spare parts from. Currently in the Dolomites’ heading to Croatia and Slovenia.
    Can any one offer some help please.

  22. Hi Brain,

    I’ve approved your comment in the hope someone will see it and be able to respond. Hope the trip is going well.

    All the best

  23. Hi, I have a 2004 Elddis caravan with Truma water heater. Took it out for first time in two years and had problems with heater. When tap is on, hot or cold. Water comes out of overflow from hot pipe out of boiler. Would replacing the connector on this hot outlet solve my problem or does fault lie elsewhere?


  25. hi all hope u can help the boiler does not work truma have tested the combustion motor & all ok I get a fault code of 89 which truma tell me it relates to 2 things the combustion motor or the DC motor but even when turned off it still clicks via the green light on the C. P. Board but when i take off the main live & earth and wait 1 min reconnect it works plerase help thanks


  26. Hi Lionel,

    I’m not a boiler specialist but leaving your comment on here in the hope someone will read it and be able to help you.

    Good luck.

    The Motorhome Vagabond

  27. Hi Gary,

    I have the same problem and if the elbow is no longer available I am going to see if I can source an inline pressure relief valve to the same pressure as the one fitted and fit this to the overflow end of the elbow. I have asked Truma technical if they have an inline pressure relief valve and at what pressure the elbow valve should fail.
    I will let you know how I get on.

  28. Hi Mark,

    Sorry for late reply. Been busy. Hope you got something sorted. It seems as users of these boilers we need to find our own solutions. There was no way I was going to spend that sort of money on a new boiler just because a simple plastic part had failed. Hopefully advances in 3D printers will help overcome this sort of problem in the future.


  29. Hi
    Going back to a problem some of you had years ago with the vent valve for the Trumatic 34000 and where people used the new part Truma Ultrastore Water Heater, Elbow Fitting, 34150-01, I now have a similar problem with the heater in my old Hymer motorhome. I was wondering if anyone still had details and images for the repairs they made using the new fitting.

  30. We are in a Sterling Elite 2004. We have a Truma water heater, on board cold water tank and an external aqua roll with pump. We’re on site, have filled the internal cold water tank and the Truma tank, but when we run the taps the water pumps from the on board tanks (we’re not sure which one) back out to the Aqua roll. We’ve tried levers in all positions, but can’t seem to resolve. Any ideas?

  31. Hi Fiona,

    I’ve approved the comment in the hope someone reads it and can give advice. Your problem is completely different to the Truma problem I had in my Hymer. Hope you get it resolved.

    All the best

  32. Thanks for the comments
    I have spent a lot of money on a Tiffian Rv and I am very upset that the warranty is only good for two years.I would say I have used the truma instant water heater a hand full of times and now it heats up once then runs out of hot water.I shut the unit off tben back on and tank gets hot then runs out.To find a certified truma water heater tech is like at least fours hours away.I have looked at all and have no idea and very upset that it is only 2 1/2 years old.Anyways if you have any idea what to check please let me know.

  33. Ensure the regulator on the gas bottle is fully open. Your heater and your hot water need more gas pressure than your oven or hobs.

Leave a Reply

Your email address will not be published. Required fields are marked *