# truma ultrasore water heater on working on 240v



## jimmyt (Jul 26, 2012)

My truma ultrastore water heater only working on 240 volt when I switch to gas you hear a click then within 10 seconds red warning indicator comes on  any ideas what problem might be.
Jimmyt


----------



## ellisboy (Jul 26, 2012)

Are you low on gas ?


----------



## jimmyt (Jul 26, 2012)

no tank almost full tried another tank to still same


----------



## Smaug (Jul 26, 2012)

You have removed the cover off the outside air vent haven't you?

If there is definitely gas & a free, unobstructed exhaust vent then your flame failure sensor is most likely the problem. Is it positioned in the flame? Try replacing it with a new one.


----------



## jimmyt (Jul 26, 2012)

yes cover is off 
is the sensor  ajob you can do yourself or has it to be a gas engineer ??


----------



## Admin (Jul 26, 2012)

silly question (but it was the way I was taught) is the gas isolator valve open?


----------



## Smaug (Jul 27, 2012)

jimmyt said:


> yes cover is off
> is the sensor  ajob you can do yourself or has it to be a gas engineer ??



Yes or no! TBH it is up to you to decide. I have changed them on my home CH boiler a couple of times over the 30 years we've lived here. I have also done them on cookers for family. It isn't hard & it doesn't even require access to the gas pipework & if you don't get it right  the heater still won't work cos the light won't stay on, but you are unlikely to die. 

I reckon the biggest problem will be access to the burner as it should be sealed & you will HAVE to make sure it is still sealed when you reassemble it - or you may die from CO fumes if it is working but the burner is dirty. OOOoohh that reminds me! My heater has a sensor on the window above the vent. *The heater cannot work if that window is open*! This is designed to stop CO fumes from a dodgy burner getting back into the van from the exhaust vent. So, do you have a window over the exhaust & was it open? The sensor is a little plastic box in the corner of the window frame with a wire leading from it! 

Gawd, these motorhome thingies are dead clever aren't they? Pity we are not quite as clever to be able to remember all the gismos!


----------



## theteapackets (Jul 27, 2012)

When something similar happened to us it was because the 12v was too low for gas boiler/heater to work.


----------



## mitzimad (Jul 27, 2012)

im not sure you can see the burner from out side on these but you need to see if its lighting and failing or not lighting at all i would try giving it a good blast out with some compressed air  as any debris is going to stop it  you can buy cans of air duster for this i doubt if there is a thermo couple on these as they have a printed circuit board  so detection will be electronic all you can do is check the probes are in place and clean


----------

