Trying to understand cooktop ignitor and controller

Thread Starter

JeremyCondie

Joined Jan 5, 2015
12
Hi Guys

My 20 years old, high-end gas cooktop is misbehaving. I replaced all the ceramic igniters, cleaned all surfaces to ensure good electrical grounding, cleaned all wire terminators and replaced the pots and servos controlling the "simmer" burners.

The thing is still not working correctly (wife not happy :-/ ) and it's the electrical issues that I'm having a hard time diagnosing. I cannot find any wiring and circuit diagrams on how a cooktop's gas igniter and control unit work, so any insights are appreciated.

(I hope/think I've addressed the obvious - damp (none), electrical earths (checked and cleaned), carbon (removed & replaced)

Issues are:
- With gas off, all (brand new) ceramic igniters spark beautifully. Once one of the burners is lit, several seem much "weaker" and struggle to light gas [I am expecting all igniters to work equally. Does this suggest the igniter controller is faulty, or perhaps an earth circuit?]
- Once all burners lit and toasty hot. The igniters are all off (no clicks). I turn down one of the six burners slightly, and all the igniters click away. (This must be an earthing or sensor issue - but where?)
- A wider question - igniters stop clicking (sparking) when the gas ignited - but there is no thermal sensor in cooktop. How does the spark igniter "sense" that the gas has just lit?

Any help is appreciated.
 

oz93666

Joined Sep 7, 2010
702
The only thing I can think of is that the ignited gas on the lit burner partially shorts out the spark gap and effects all other's ...This is not too surprising a flame is plasma (ionized gas) ... But the system is designed to tolerate this so it maybe placement of the igniters , or not enough voltage from source that is the issue.
 

BR-549

Joined Sep 22, 2013
4,938
If I am understanding correctly, that is a terrible start and control strategy. You might want to verify that.

I would think that power is only supplied to the igniter, when the heat knob is in the light position.
 
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