Duet Dryer GEW9250PL0 temp controls not changing temp

[jimgil23]

Model Number

GEW9250PL0

Brand

Whirlpool

Age

More than 10 years

Dryer heating but temp controls only work on high or medium. Low, extra low and air only controls stay at medium. Air only is heating (I can see the heating element is on.) Tested thermistor at room temp and 100 F and resistance is within spec. Already tested heating element, thermostat and thermal cutoff. All OK. I'm thinking the heater relay on control electronics board may be faulty. Does this make sense?

 

[Jake]

Hi, If your absolutely sure your heating element is not shorted to your heater housing ground, then yes, it could be a stuck relay on the control board, thus that's why it would heat on AIR DRY.

Unplug your dryer then look on the control board and you will see a black relay marked HEATER, Ohm the 2 terminals on that and see if you get continuity.

Here's the control board for your model:
WP8546219 Control Board


Jake

 

[jimgil23]

I checked the Ohm resistance from P2-5 and P2-6 on control board and got around 11.27. The tech sheet says it should be 6-7 and if higher then replace thermistor. This reading is about what I checked the stand alone thermistor to be at room temp. Is this this coincidence or is the spec suggestion wrong. I will check the relay next and advise. I did check the heating element for a short and didn't get and continuity to case from both leads. I did get continuity from lead to lead.

 

[jimgil23]

The resistance on heater relay showed OL on the Ohm setting and no sound on the continuity setting. is this correct?

 

[Jake]

I've never seen the thermistor cause the heater to stay ON . I have seen the thermistor cause a NO HEAT problem.

You can ohm test the thermistor at room temperature. P2-5 and P2-6 on control board is the leads going to the thermistor, test the thermistor itself, with the leads on it, at the thermistor, not at the board.

At room temperature or 70*F the thermistor should show between 11.5K and 11.9K ohms (11,500 -11,900 ohms).

Normal thermistor resistance values:
60 degrees F. - 15.3K ohms.
70 degrees F. - 11.9K ohms.
80 degrees F. - 9.2K ohms.

Here's the thermistor for your model:
Thermistor WP8577274


This video shows how to access it:

https://www.repairclinic.com/Repair...Electric-Dryer-Thermistor-Replacement-8577274

Make sure you unplug your dryer first and keep it unplugged when ohm testing.

The resistance on heater relay showed OL on the Ohm setting and no sound on the continuity setting. is this correct?

That's good, it should not show continuity with the dryer off and power disconnected to the dryer.

What is odd is you should NOT be getting any heat at all in AIR DRY/NO HEAT cycle.

Jake

 

[jimgil23]

Thanks and I must be missing something. Thermistor tests to 11.9K Ohms at 70 degrees. I'm putting the dryer back together and will see what happens. Anything else I should test?

 

[Dan O.]

Already tested heating element

Tested it for what exactly?

If your absolutely sure your heating element is not shorted to your heater housing ground

An element shorted to ground could still test normal for resistance but at the same time be shorted to ground.


Did you specifically test it for a short to ground and not just for resistance at the control??

Dan O.

 

[jimgil23]

I must have miss interpreted my original reading because now the heating element shows continuity to the case from either lead. I will replace heating element. Does that make sense?

 

[jimgil23]

I had the same heating element from my dryer that was repaired with a broken coil. I kept it just in case and tested it before installing while waiting for my new heater element. Continuity was good and no shorting to the case. There was no heat on air cycle but when put on any heat cycle I got an E1 error code after a short time. I tested thermistor and it showed the correct Ohms when cooled to room temp 70 degrees. when thermistor was still cooling the Ohms were lower as expected. Could the old heating element be the reason and/or could the circuit board have gone bad. It was OK previously. Thanks for all the comments.

 

[Dan O.]

the heating element shows continuity to the case from either lead. I will replace heating element. Does that make sense?

Yes.

I had the same heating element from my dryer that was repaired with a broken coil.

That might be ok for testing purposes but I wouldn't leave it that way.

I tested thermistor and it showed the correct Ohms when cooled to room temp 70 degrees. when thermistor was still cooling the Ohms were lower as expected.

If any of its measurements are incorrect it points to a defective part.

Could the old heating element be the reason

I don't see how.


Dan O.

 

[jimgil23]

The problem started with the dryer heating on air cycle. It was the heating element being shorted out. Now I have the E1 code so could I have damaged the circuit board while testing the thermal relay and the P2-5 to P2-6. Waiting to install new thermistor to see if this works. If not, then should I replace circuit board.

 

[Dan O.]

could I have damaged the circuit board while testing the thermal relay and the P2-5 to P2-6

Anything is possible however if the testing was done with power disconnected, it is unlikely. It is possible just a wire has become disconnected to that circuit and is now responsible.


Dan O.

 

[jimgil23]

Tried new thermistor but still E1 on heat cycle. Anything else I should test while waiting for control board.

 

[Dan O.]

Anything else I should test while waiting for control board.

The only other thing I can think of is the wiring in between. Maybe it got damaged somehow and the control isn't able to detect the sensor? See if you get the same readings at the sensor and at the wires where it connects to the control.


Dan O.

 

[jimgil23]

Not sure what wiring to check. Can you be more specific so I go to the right place.

 

[Dan O.]

Jake said previously:

P2-5 and P2-6 on control board is the leads going to the thermistor,

If the measurement between then there is the same as the readings directly at the thermister, it should indicate the wiring in between is Ok and not likely the cause. (Also make sure all connectors are attached securely as well.)

Dan O.

 

[jimgil23]

When I checked originally, I removed connector to the P2-5 and P2-6 and put the probes from the Ohm meter into the slots to measure resistance. Is this Ok or should I try to access the open slots on the side where I can see the metal connectors.

 

[Dan O.]

put the probes from the Ohm meter into the slots to measure resistance. Is this Ok

I would think that is sufficient. Did you get the same readings there as directly at the sensor connections? If the readings are the same in both locations it should indicate the wiring between is Ok.

Dan O.

 

[jimgil23]

This is how I checked originally and got the same resistance value as on the thermistor directly. I'll recheck and let you know. Thanks

 

[jimgil23]

I checked the wire connector after unplugging from the control board. It has the same value as thermistor 11.74 kOhms. The dryer code of E1 comes on after about 1 minute and flashes