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.
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.
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.
