Thermador Range RDFS30QB Burner Won't Light

[Dswinty1]

When I turn this bad burner on there is gas but no spark.  This is not one of the XLO burners.  When I turn on one of the good burners the ignitor on the bad one does spark.  I am wondering which part might be bad?  Spark module, spark ignition switch or something else.

 

I appreciate any help

[Budget Appliance Repair]

Sounds like it's going to be the ignitor switch on the gas valve that doesn't spark when you turn it on.

[Guest]

On 3/2/2024 at 5:13 AM, Budget Appliance Repair said:

Sounds like it's going to be the ignitor switch on the gas valve that doesn't spark when you turn it on.

Not to argue your solution; just to discuss because I don't personally know.  

They said the bad burner will run gas but no spark but turning on a good burner will cause the bad burner ignitor to spark.  

If the ignitor on the bad burner turns out to not bed bad would this more likely be an issue with the wiring that goes from the bad burner knob to the ignitor? I've noticed on our fairly new gas stove all ignitors spark when only one burner knob is turned to te ignitor position.

 

[Budget Appliance Repair]

@Dr. Horshenschwartz As far as I know, (been doing appliance repair for 39 years), all electronic surface spark modules spark all ignitors no mater what burner is turned on.

If all the ignitors spark when you turn any burner on except for one then that switch, (or possible wiring to that switch), is bad.

You can light the burner that doesn't spark by lighting another burner and leaving it sparking and turn on the burner that doesn't spark and gas will come out and light because the ignitors are sparking because of the other burner you still have in the light/spark postion.

[Guest]

On 3/4/2024 at 7:34 AM, Budget Appliance Repair said:

You can light the burner that doesn't spark by lighting another burner and leaving it sparking and turn on the burner that doesn't spark and gas will come out and light because the ignitors are sparking because of the other burner you still have in the light/spark postion.

I understood the original post to say the bad burner would not spark when turned to the ignite position but if they turn a different burner to the ignite position it caused the bad burner ignitor to then spark. That's why I was thinking that it could be a wiring issue; but I don't have a diagram in front of me to confirm but it seems like there would be a wiring issue. 

Here's my thought process in short. 

Any burner knob in ignite position causes all ignitors to spark at the same time. But somehow a single burner knob position can cause that burner to not spark and potentially no burner ignitor to spark (not clear in the post) but any other knob can cause that bad burner ignitor to spark? 

I've never examined the wiring layout myself, but just thinking about what would be necessary to allow and stop electricity to flow like that is quite the electrical engineering idea. 

Again, I'm not saying you're wrong, I'm just not understanding why the designers would build in redundancy in one direction yet create a wall in another part of it. 

I should just find a wiring diagram because I'm guessing this will come off as argumentative when it's truly not meant to be; I just find electrical theory interesting. 

 

[Budget Appliance Repair]

@Dr. Horshenschwartz It's just the common way these spark modules are wired.

If it's just a basic spark module, (Not a re-light type that senses the flame), then you only have a Neutral and Line to the spark module.

Each burner valve has it's own switch so when you turn any burner on it completes the circuit to the spark module and all ignitors spark.

Sometimes the complete four switches are wired together in a complete harness and the only way to replace is all four at once.  Some each have there own individual switch that can be remove/unplugged from the wiring harness and replaced individually.

Any of the individual four switches can fail so you get absolutely no spark on any ignitor when you turn on the burner valve with a bad switch.  The valve is mechanical, so the gas comes out rather the ignitor is sparking or not.  The work around is to just light that one burner with a ligher each time or know that you can turn any other burner on and leave the ignitors sparking then turn the bad one on and it will light because the ignitor is sparking because of one of the good burners being lit and causing the ignitors to spark.

[Guest]

6 hours ago, Budget Appliance Repair said:

@Dr. Horshenschwartz It's just the common way these spark modules are wired.

If it's just a basic spark module, (Not a re-light type that senses the flame), then you only have a Neutral and Line to the spark module.

Each burner valve has it's own switch so when you turn any burner on it completes the circuit to the spark module and all ignitors spark.

Sometimes the complete four switches are wired together in a complete harness and the only way to replace is all four at once.  Some each have there own individual switch that can be remove/unplugged from the wiring harness and replaced individually.

Any of the individual four switches can fail so you get absolutely no spark on any ignitor when you turn on the burner valve with a bad switch.  The valve is mechanical, so the gas comes out rather the ignitor is sparking or not.  The work around is to just light that one burner with a ligher each time or know that you can turn any other burner on and leave the ignitors sparking then turn the bad one on and it will light because the ignitor is sparking because of one of the good burners being lit and causing the ignitors to spark.

Thank you