Fridge Piezo ingition (1 Viewer)

[Hilary Owen]

Our Dometic RM7401 recently renewed burner and igniter pack. Everything working fine but while away the other weekend my husband heard the piezo operating quite a few times during the night. Later I noticed the gas indicator was flickering and the piezo sounding, light came back on all good. Any suggestion of what's happening or do we need to replace the gas control valve. TIA

 

[Mike800966]

If the gas indicator ( yellow light) is flickering it means the flame has not yet established, hence the ignitor clicking to relight itself.
There are several different ways of the flame being monitored. On our 7401 its a thermocouple in the flame. was it very windy or was the gas pressure low, the fridge burner is fed by quite narrow pipe unlike the central heating or the cooker .
If it continues to happen I should make sure the ignitor is correctly positioned in the burner head or get it checked by whowever fitted it
Mike

 

[autorouter]

Later I noticed the gas indicator was flickering and the piezo sounding, light came back on all good. Any suggestion of what's happening or do we need to replace the gas control valve. TIA

Another way the flame is monitored, instead of a thermocouple, is a resistive measurement through the gas flame, which is ionised and is quite conductive compared to air. Maybe you can see if the flame is a bit weak, due to the jet being partly blocked etc. If it gradually is getting worse then maybe it needs a good clean and service. Assuming the pressure is OK and the gas is not running out, of course. As it's a new burner maybe the flame detector electrode is badly adjusted. Also it's possible that particles of rust from the inside of the old pipe could have partly blocked the jet again.

Being very pedantic, it will be an electronic spark generator, not a piezo-electric spark. Piezo ignition is the older type where you repeatedly press a button, and get a loud click, and a spark for each click.

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[rosalan]

I once had a similar experience when the cable to the injector kept shorting out on nearby metal. That was a long time ago and things should have got better now.

 

[Mike800966]

That would be the nylon coated HT wire to the ignitor, its quite a high voltage and will always take the easist path- will make you jump!
Mike