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joatmon

Thermador Simmer burner: bad solenoid or potentiometer

10 posts in this topic

I have a Thermador duel fuel 6 burner range & stove (PRDS366US).

One of the Star Simmer burns wasn't working at all. It sparked but there was no click of the gas solenoid and no gas hissing.

I took it apart and it magically started working so I just cleaned things up and put it back together.

Then after a while it started working intermittently.

I.e., sometimes the solenoid clicks on, the gas hisses, it sparks and it lights but sometimes it just sparks without the solenoid clicking open or the gas hissing.

On the XLO simmer setting, I can see that the time delay still works before it starts sparking, so I would think that means the potentiometer is working (since presumably that controls the delay and triggers the spark after a given delay) but that the solenoid is broken. I.e., I am guessing that the potentiometer controls a timing circuit that triggers the solenoid to open/close and the spark ignitor to trigger after a variable amount of time. And since the sparking is still responding to the variable timing, I am assuming that part of the circuitry is OK.

- Am I understanding the working of the electronics properly?

- If so am I correct in thinking that the fuel solenoid is the most likely culprit?

- Given that the problem is *intermittent* is it likely that the solenoid is broken (needing replacement) or is it more likely a bad/corroded connection?

- Any suggestions on how to troubleshoot?

Thanks

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Need appliance parts? Call 877-803-7957 now!

One more clarification. The other simmer unit works just fine...

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Well no replies but I am now pretty convinced that it is the solenoid valve. As a test, I switched the wires which resulted in the symptoms switching to the other knob - meaning that the potentiometer and other parts of the simmer control unit work and thus in my mind conclusively isolating the problem to the solenoid valve. I have ordered a new valve which should arrive tomorrow.

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Nice shootin'! Those solenoid valves are common troublemakers. An easy way to check them is to measure the resistance of the coil at the terminals. With your meter on the Rx10 K scale you should get about 1760 ohms.

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Yes - I forgot to mention that I also put my digital multimeter on it and found an open circuit across the presumably broken solenoid and I got a similar reading to the normal one you quote on the working solenoid valve

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Meter on the Rx10K scale?

Edited by Samurai Appliance Repair Man
Rx10K scale, not Rx10!

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digital multimeter

on the 2k (2000) OHM scale

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I used the 2K scale and it was about 1.7Kohm

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- Any suggestions on how to troubleshoot?

For manuals and lots of other goodies,

become an Apprentice==> http://appliantology.org/apprentice/

was about 1.7Kohm

that's correct

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Sounds like you done nailed it, Hoss. :smokin:

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