Truma Combi boiler/heater fault

Agreed👍🏻, preprogrammed kit can develop a fault that can then be solved or helped by a software update. A lot of software updates in tech are for increased efficiency not primarily to update. The hardware needs physical intervention, software-not so much.

Hi guys, found this thread and wondered if the combined years of caravanning might help.

On site, on EHU and found water wasn't hot. Checked and found the main caravan control panel off and Truma panel also off. When I went to check the fuses I noted the fridge (on 240v) was off. Battery charger working. Very confusing?

Back to main control panel and pressed the 'on' button and it came back on. Also noted the fridge had come on?

Still hadn't solved the 'why no hot water'. Had hot water set at set at 40deg previously so set temperature to 60deg. A little while later, water still cool. Had a look at the Truma 'combi boiler 4E', Nothing visually untoward so removed the half cover to expose the 12 v wires. Found all wires correct but no flashing warning lights on the PCB to show it was malfunctioning. Checked 10 amp fuse on the board which showed 12v to the board. Looked at the truma control panel that had the normal display and thought resetting might cure the fault. Reset and when init (alising) found the panel could not see the boiler. I was now shown a clock and a spanner! It then gave the fault code W255H. Phoned Truma who, as soon as I said no lights on the PCB, that the board was broken!

Sent board for repair and was told it had a faulty voltage controller. Repaired and returned and now fitted. Sadly but positively. The board is still as dead as a dodo but I now don't get a fault code!

Waiting now to hear from the repairer.

Anyone on here have the answer to the conundrum?

I also put the post on here out of frustration, because, quite frankly, for the amount of time this has been used, always on EHU, never on gas and the heater used infrequently. The van is only 3 1/2 years old. I think the quality of the unit and the cost to repair it is extraordinarily expensive for what is a pretty ordinary piece of kit. And I see they now offer a smart controller? Perhaps a little more spent on producing something reliable might make people happier?

We have the same boiler and have had the E 89 H code appear three times during the year. On each occasion it was me that turned the heating on and each time I forgot to turn the control panel to the correct setting (EL2 for us) first. 

Once we have returned home we have set caravan up on drive and never had the fault code reappear. I therefore assumed it was due to user error (me!)? Or perhaps even specific site electrics?

I've Googled the code and found numerous threads discussing motor board errors and software updates and basically concluded that this could be an intermittent fault on these boilers.

I for one shall be paying close attention to this discussion and am pleased it has been revived!

Exactly what Club Together is for. IMHO.

We occasionally get E255H errors, usually  because I had not powered the unit down properly before disconnecting the EHU cable.

Personally I always carry a spare convector heater just in case. But we shouldnt really have to. Should we ?

Perhaps if Truma had more competition in the Market their quality control would be better ?

 

One issue with the Combi 4e, is the electric elements fail, particularly the one used on the 4 amp setting. Ours did - no hot water.

Setting the controls to 8 amps brings in the second element (the working one) result is hot water

Perhaps try this

Another E 89 H fault here in our motorhome.  I disconnected the EHU, disconnected the leisure battery, removed the Truma control panel and unplugged its cables, pushed the reset button on the boiler, all to no avail.  After resetting the system via the control panel, the INIT.. phase left behind only two icons, the clock and spanner. We had to borrow a fan heater to stay warm.

After another hour of head scratching and internet trawling, my wife found that "fuse 12 might be implicated" and "there is a fuse 12 protecting one of the headlights". To put this theory to bed, I started the motorhome engine... both headlights were fine.  However,  five minutes later I noticed the control panel came back to life with a full array of icons and the fault vanished.  Heating was back working! 

I have no idea whether the engine restart made any difference, but I suspect not, and this won't help caravanners who don't have that option.

My gut feeling is the system needed an hour or two to reset itself, possibly while the water tank cooled down below a certain temperature perhaps? 

Intermittent faults are always the hardest to find.

So, none the wiser, but a little older and greyer...

 ...the moral for me is to carry an emergency fan heater now.

 Thanks Truma - so reliable that I have to carry two of you!

We've been carrying a small fan heater for years. Not only is it an emergency standby but it also blows cold for those hot weather days.

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Note the Truma panel does sometimes default to Gas and its important to check before putting the heating on.

Is that perhaps an option in settings. Our gas is on all the time, except when in the storage compound. If left set on electric 1 or 2 when last switched off, it has never yet defaulted to gas. It didn't even do it when I forgot to switch on the EHU, it just threw up an error code for no electric.

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