Truma boiler red light coming on

[theapples]

Good evening all, I have a possible problem with my Truma Combi 4 boiler/heater. After it has been on for a while (Blown air heating) a red light on the control knob starts flashing and continues to flash. The Instructions say this is due to low voltage <10.5v. However in last two weeks I had a habitation check/service and the batteries were good with no problem. When flashing the battery indicator on the van control panel reads 12.4v. This first happened a few weeks ago and I put it down to low voltage since we had not been on EHU for a week and had only driven short distances. (I do not have solar but have 2 x 85amp hab batteries). This time the van had been on EHU at home, we then drove 85 miles to Exmouth and fault started next morning. Even though red light is flashing heater still works. Any ideas please.

 

[monzer]

I could be wrong but this sounds very similar to the problem Northernraider had. Seemed to be some kind of voltage drop before the power hit the heater.

 

[Northernraider]

Yeah that's the same as mine was doing

I temporarily fixed mine by wiring straight to the battery.
But I have it wired back through the system at the minute and it seems to be fine now so I cant actually tell you what was wrong with it.

 

[Wagoneer]

Could possibly be low gas pressure or a partially gummed up gas regulator.

 

[TerryL]

May be something as simple as poor electrical connections - how easy is it to check on your installation, some of them can be a b----r!

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[jezport]

12.4v at the panel, but what at the boiler?
Read the blink code at the boiler, it will tell you why it went to fault.

 

[theapples]

Thanks for all ideas so far. I don't think it is a gas problem. I had regulator changed two weeks ago since it was 9 years old and the fault was showing before this. I'll get the volt meter out when I get home next week and get in the garage to check the fault code and check the power supply. (That should be fun)

 

[john prince]

I currently have a similar problem, red light comes on after small fan heard to spool up. when asking for Hot water or heating,(Elect. or Gas) Is there a `Blink Code? if so, where can I get the info? (Due to nature of installation, unit is facing away from me on a shelf in the Motorhome's garage.-hence unable to get to potential fuse(s) etc.) Motorhome booked into dealer for look at (under warranty)!

 

[Bessy765]

A fixed red light is a gas problem, a flashing one is low voltage. Given how some makers use thin wire to save cost then users suffer a voltage drop. If the light is a bit sensitive it will flas earlier than others?

 

[Landy Andy]

I currently have a similar problem, red light comes on after small fan heard to spool up. when asking for Hot water or heating,(Elect. or Gas) Is there a `Blink Code? if so, where can I get the info? (Due to nature of installation, unit is facing away from me on a shelf in the Motorhome's garage.-hence unable to get to potential fuse(s) etc.) Motorhome booked into dealer for look at (under warranty)!

If a solid red light check your gas. Are other gas things working? If yes, it may still be gas issues and often gummed up regulator that doesn’t allow enough gas through for boiler.

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[dunnah01]

Sometimes just resetting the main control panel works. A dumb question but is the gas turned on at the internal valve?

 

[Pausim]

However in last two weeks I had a habitation check/service and the batteries were good with no problem.

A hab check might cover the voltage at the time but I doubt they did a slow load test to see whether they can sustain a load in prolonged use. How old are the batteries? When batteries sulphate with age they will still charge up to a normal voltage but lose capacity i.e. what started off as a pair of 85Ah batteries might now only be capable of holding half that amount. The batteries may recover a little when the load is removed by the boiler shutting down, before recharging them try turning on lots of lights and the water pump to see if your 12.4V drops off quickly.