Truma water heater red light on

[Camper634]

My van is fitted with a truma hot water boiler which can be run on either gas or electric.We are away for the weekend and everytime I try to run it on gas you can hear the solonoid lifting but not the ignition clicking and after about 10 seconds the red light comes on and it shuts down.
I have plenty of gas
The batteries are fully charged
Im off grid so can’t use electric.
I have removed the outside cover
Has anyone had a similar experience please,and if so what was it?
Im thinking ignition problems and wondered if this is a part that’s easy to get at and replace?
Hoping it’s not a PCB problem because I think they are really expensive.
Any suggestions would be appreciated as I am in desperate need of a shower,according to my wife.

 

[Camper634]

Just an update.Fitted a replacement gas regulator but the problem persists unfortunately.Having had a better look once we got home,this is what I have determined.
The gas burner does actually light more or less with the first spark.The sparking still continues until the boiler locks out,about 10 seconds in total.I’m thinking now more of a problem with the flame failure device or the dreaded PCB.Occasionally it has stayed on for 5 minutes or a little more before shutting down.I have no idea how to gain access to the burner without taking the whole boiler apart.Can’t continue with cold showers though in this weather.

 

[Phill D]

i had the same problem some months ago, went through all the tests and it ended up being the pcb. which in my case was not difficult to change as it can be done through the bottom vent. £150 for the part and around an hour with lots of pictures on the phone to remember the wiring placings..

 

[pappajohn]

Ignore.....just seen post #31..

 

[sonar]

Just an update.Fitted a replacement gas regulator but the problem persists unfortunately.Having had a better look once we got home,this is what I have determined.
The gas burner does actually light more or less with the first spark.The sparking still continues until the boiler locks out,about 10 seconds in total.I’m thinking now more of a problem with the flame failure device or the dreaded PCB.Occasionally it has stayed on for 5 minutes or a little more before shutting down.I have no idea how to gain access to the burner without taking the whole boiler apart.Can’t continue with cold showers though in this weather.

Yes I I have been following the wrong post.
I have the same problem. But it seems one of the options is to clean the burner and other bits.

well as I have had to fix a few leaks it had to come out anyway.

it works on 240 volts but would not stay alight more than a few seconds.

I have removed it all the cover off and then went further just to clean it up.
the last image shows the burner .
the single wire prong is the thermocouple. The two wires just apart are the ignighters.

all cleaned up now .

when I put it all back together again next week hope fully it will work.

it. Is a lot of messing about removing the whole unit and then stripping it down .

when it is fitted again it will be loose so as it can be tested .
if it then still does not work. I will have to see if the board shows any damage.

if not it has to the thermocouple.

afterbthat I have no idea YET what to do .

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[sonar]

I can’t see any burnt out or discoloured components.

even the fuse is good and looks like No dry solder joints .
so now we’re back to the gas burner .

I not going to know for a while yet .

 

[Ingwe]

If it's a Truma regulator more likely its that.

That’s what my money’s on!

 

[sonar]

Gas comes out of the pipe.
tested It by turning the gas on . The pipe hisssses.
the gas works on the fire and the hob and now the water heater.

 

[Camper634]

I had all the same symptoms and got most of the same replies.Swapped the regulator and it made absolutely no difference.Swapped what looked like a perfectly good PCB and it’s now working perfectly.

 

[sonar]

BOOM it’s now working just needed a good clean fired up first go.

so cleaned the gas ring and removed the thermocouple cleaned it cleaned the two wire for the ignition .
found a not so good connection wire from the thermocouple that connects to the underside of the pcb .

put it in rough position connected gas and wires and held my breath click it went on
never went off dash to the back of the van and I can feel the hot exhaust .
run back in turned it off..

but I thought I was going to have price up the thermocouple and a pcb board and a gas valve.
already priced most of it and it would Have cost not far short of a new one.
most likely would have gone for a new one with the warranty for two years.
well pleased I saved a packet.

back on with the plumbing bits when they arrive and then put it all back again.
they started leaking the second I touched them seems there all really tight pipes and fittings no wiggle room.

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[AndrewS]

Have you checked the flash code on the PCB that will tell you what the fault can be?

https://www.dometicrvcentre.com.au/documentmanager/item/139

What a brilliant piece of advice! Our Truma wasn’t working on either gas or electric, I thought the PCB was just flashing red erratically, I didn’t realise it was talking to me. Short, S,S, Long, SLSL, a fault with room thermostat. Soon found a mouse chewed wire tucked right down at the back. Probably saved me £100’s. Thanks so much.

 

[solitaire]

I'm having the same problems with my Truma - its an old one and have been told that parts are not possible to get etc etc - its discontinued but the same thing it works intermittently when you turn the dial to heat the water. The green light and orange light comes on the dial - then you hear a double click and the red light comes on and nothing happens .......