My electric /gas hot water system, wont heat up on gas. The flame starts and after about 10 seconds it turns off. I checked the connection to the flame sensor it is connected ok and there is continuity from the board to the sensor probe. I have not carried out a resistance test to see if that varies when the flame is on, that is if there is a difference. Any ideas on what could be wrong, and how to test if it is the sensor which is faulty.

If it's a Truma unit are you taking the cover off the outlet  Klaus.

No it is not a Truma.

I have had the van 6 years, the H/W unit has worked fine on the times I had to use gas, the fridge and stove work well on gas, so it appears the regulator is ok, the problem appears to be with the H/W unit. It is a pretty simple system really, gas ignites and burns, if there is no flame detected the whole lot shuts down, which is what is happening. But I am unsure if it is the flame detector, the circuit board or some other fault.   

Get a gas technician to sort it. 

I had wasp get into the water drain tube that partly flooded the burner

Cleaned tube out and fine after that

Thank you for your reply I will check that out.

Thanks PeterinSA I will investigate the regulator, thank you for the info. 

When mine went several years ago with similar symptoms, the problem was the regulator.

At the time, the gas cooker worked OK as did the gas side of the 3-way fridge.

The HWS would start & run on the pilot burner but not on the much stronger heater jet.

A Gas Fitter informed me that the regulators became blocked progressively by the stuff that is added to make the gas smelly.  Consequently, the regulators need to be cleaned if possible or replace the unit every several years or so.

Thank you to all who have replied, I will check all the equipment mentioned.

Hope you all had a great Christmas

Hi all I have an update on the problem of the gas hot water unit turning off after a few seconds.

I checked the gas sensor, it appeared to be ok, cables ok as well, I unplugged the connection plug and cleaned all of the connections on the control unit and the plug. Problem solved a tiny amount of dirt on the connection pins appears to have been the problem, I am a happy chappy now. 

Good to see an update Klaus, many just don't bother after efforts made to help. Happ to hear you are a happy Chappy now. That's like being a happy camper or even a happy little vegemite.



Keep Safe on the roads and out there.

Edit.....I had problems with a instant hot water heater from new. It didn't know what hot water was, not even warm water. No one could find the problem and they wouldn't replace it. I bit the bullet and replaced it with a Suburban and love it. I had trouble with a gas heater fitted in the aluminum tent, it started but went out about 60 seconds later. Turnes out it was an adjustment needed in the main regulator on the gas bottles. Good since. Only late last year I replaced the regulator with a new one as was 10 years old and I was doing maintenance work around the A Tent. I'm a happy little vegemite now.