Truma heating issue

[S m w]

Can anybody help I’m away on site at present came back from walk to find Error code E746 H and no heating tried various resets without success and no corresponding code in truma handbook and tried help lines
Any ideas
Thanks
Steve

 

[irnbru]

Are you on EL2 by any chance? What Truma system is it?

Have a look here.

www.slideshare.net/tmcleisure/truma-combi-fault-codes-2018-tmc-leisure

 

[S m w]

Yeah I’m using el2

 

[irnbru]

Is it a Truma CP? How long was the heating on? I think you will find the RCD has tripped.

 

[David and Sally]

Fault No.: 0746
Flashing code: ls llls lsls
Fault description: Fault in the electronics
1. Action: Ensure 12 V voltage under load at appliance input and check for AC
voltage components that can be generated by the power supply unit
or solar system.
2. Action: Replace the electronics, enter heater serial number on the new
electronics using the Diagnose Tool


No sure I understand that!!!

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[two]

Not familiar with the error codes.
I assume that the gas supply is sound? It may be 'poor' if it's very cold or you're near empty and have a Butane mix in the LPG.
I assume that the 12V supply is sound? I think it may not respond well if the battery is very low.
Or are you just using EHU for power?

 

[irnbru]

Fault No.: 0746
Flashing code: ls llls lsls
Fault description: Fault in the electronics
1. Action: Ensure 12 V voltage under load at appliance input and check for AC
voltage components that can be generated by the power supply unit
or solar system.
2. Action: Replace the electronics, enter heater serial number on the new
electronics using the Diagnose Tool


No sure I understand that!!!

No idea what Truma system they are for, nor what the OP has but came across them .

Not familiar with the error codes.
I assume that the gas supply is sound? It may be 'poor' if it's very cold or you're near empty and have a Butane mix in the LPG.
I assume that the 12V supply is sound? I think it may not respond well if the battery is very low.
Or are you just using EHU for power?

The OP is using electric.

 

[S m w]

Thanks for all your replies looking at a complete shutdown at moment
Not been able to change to gas supply either
But managed to gain a temporary heater
Will look at problem and help lines again tomorrow
Regards
Steve

 

[irnbru]

Have you checked the RCD trip switch?

 

[S m w]

All mcbs and fuses seem good

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[two]

No idea what Truma system they are for, nor what the OP has but came across them .




The OP is using electric.

Ah! that's the EL2 reference (I only use gas).

So - Does it work on Gas?

 

[S m w]

No luck with complete shutdown
Rcd is ok
But can’t get boiler going on gas either so no hot water either
May have to wait till when various help lines are again open for business
Tried 12v as well no luck
Oh well perhaps these faults happen sometimes
And My van is only 4 months old ?

 

[S m w]

Monday ?

 

[David and Sally]

Oh well perhaps these faults happen sometimes
And My van is only 4 months old ?

Ours packed up after only 2 month's use. Turned out to be the room temp sensor but I am still concerned about the number of Truma systems reported faulty on this forum.

I'm not sure Trumas are as good as they should be.

 

[SteveRallye]

Hi had similar thing 2weeks ago ran out of gas and same code could not find anything on internet. Luckily a great guy (Brian) onsite suggested reseting boiler. So what I did I tripped out the main van electrics, then reset. Went into boiler cupboard and found the obscure little reset button on the top r/h front (the opposite end to the online manual) there was a small cover to prise off, Held it in for 20secs and bingo it relit. Hope this helps.

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[S m w]

Hi steve
Thanks for your comments
I’ve not seen a reset button on my boiler so I will look for that reset button tomorrow morning
Much appreciated
Will let you know ?
Steve

 

[dipsie]

Had a problem last winter. My wife kept complaining she was cold, not unusual, in chilly weather in the camper. I kept increasing the temperature on the control panel, several times.
Later lying in bed I got so hot that I started turning the heating down, several times !
Ah, it dawned on me what was causing the heating to keep cooling down. Where my wife likes to sit if reading or watching TV the temperature sensor is immediately, 5 - 6 inches above her head so the next day I got her to sit elsewhere away from the sensor. I set the temperature at 21 degs and it maintained it.
I know she can be a bit “ hot headed “ at times , try explaining about the heating systems, forget it !
A while later at home I took the panels out of the bottom of the overhead lockers, wife’s side and pushed out the sensor, unplugged and lengthened to wiring, drilled another hole approximately one metre away from the original hole, reconnected the wiring, fitted all the panels back and covered the old hole.
Did it solve the problem ? Yes, we have not had any grumbles about the heating since.
I was going to e.mail Auto Trail and advise them of my mod but though twice about that as they might use that to reject any possible future warrantee issues with the heating.
In our V Line camper the best position to sit with one’s feet up is with a cushion/pillow against the rear doors, heater sensor immediately above your head and also the heater unit and rear most vent under yer bum.
This is probably another case of the designer never using their brains.

BernieT

 

[irnbru]

Ours packed up after only 2 month's use. Turned out to be the room temp sensor but I am still concerned about the number of Truma systems reported faulty on this forum.

I'm not sure Trumas are as good as they should be.

I agree. We are waiting on a new RCD for our van, quite a few I've also heard of having faulty units.


S m w Are you sure you have water in your boiler?

 

[two]

If gas and mains are failing to do anything, it would appear to be a Truma problem.
Is everything else 12V behaving? Just trying to eliminate the 12V supply possibility.
When new things fail, it's usually (at the most inconvenient time and) in the earlier days of use. Hopefully, Truma will be swift in providing a resolution.
If you have EHU, i'd get a fan heater (they're not expensive) to tide you by. Hot water will have to be from the (gas) kettle (reminds me of my early caravanning days, before today's mod cons).

 

[Mark and Mindy]

We had a fault with our Truma boiler at Christmas and it was EHU power related.

I tried to use the truma control panel screen to reset the error many many times but to no avail. I also tried removing all electrical power from the van including 12 volts by switching off at the main relay box.

Eventually I managed to clear the fault by following the Truma boiler reset procedure.

To reset our truma boiler I removed the control panel cover and underneath and on the right hand side there was a red flashing light. The red flashing light actually flashes in a sequence which gives the fault code but at the time I couldn't diagnose the fault code as it was not in the physical copy of the user manual and we were in such a remote area that there was no internet access.

Also underneath the control panel cover on the left-hand side and towards the center there is a small round hole. I pushed the rear end of a plastic BIC pen into the hole. It was quite a tight fit and would only just fit inside the hole which was at an old angle and was a centimetre or so deep. I would not recommend using a metal item because they may be electronic components and it might cause a short circuit or something. I think I felt a click but I'm not sure and if there was a click then it only clicked once which means that the fault had caused something to pop out internally and the reset was to push it back in. On the second attempt this seemed to clear the fault and the red flashing light changed to a steady green light and then the boiler started working.

It was Christmas day at the Great Langdale campsite in the Lake District and do it was a big relief to get it working.

I hope that this explanation helps someone.

Mark

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[Lenny HB]

I am still concerned about the number of Truma systems reported faulty on this forum.

Considering the number of Combi's fitted the number is very small. They have been fitted to probably 80-90 % of all Motorhomes for over 20 years.