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Pat Barry
03-30-2014, 11:10 PM
My daughters gas clothes dryer doesn't heat up properly. Its a fairly new Whirlpool Model LGR36Z4JQ1.

Here is what it does. When it is cold, ie: hasn't been running for 10 minutes , and you start it up, it actually does heat up, one time. Then the operating thermostat senses it has heated to operating temperature and it shuts the gas valve off. OK - this is all as it should be.

The problem is that when the operating thermostat senses the temperature has dropped and it puts power back to the gas valve. There is a resistor that heats up (glows red hot) and that is what is supposed to light the burner. The problem is the burner won't light up again, at least for a good long time.

The operating thermostat is actually just a thermal switch and it is adjustable. There is a screw adjustment to set it anywhere from 140F to 155F (the temperature it opens at). It closes again when the temperature drops by 5 degrees. The idea is that this thermostat switch cycles voltage to the gas valve and thereby maintain the temperature for the dryer.

I suspect the problem is the gas valve is getting overheated. After some time (again, maybe 10 to 15 minutes of non-operation) the thing will light the burner again and once again it heats up and repeats the single heating cycle. As near as I can determine the electrical circuit is working as it should be, its just that the gas valve is disfunctional. Has anyone here had any experience trying to fix one of these?

Michael Mahan
03-30-2014, 11:37 PM
My daughters gas clothes dryer doesn't heat up properly. Its a fairly new Whirlpool Model LGR36Z4JQ1.

Here is what it does. When it is cold, ie: hasn't been running for 10 minutes , and you start it up, it actually does heat up, one time. Then the operating thermostat senses it has heated to operating temperature and it shuts the gas valve off. OK - this is all as it should be.

The problem is that when the operating thermostat senses the temperature has dropped and it puts power back to the gas valve. There is a resistor that heats up (glows red hot) and that is what is supposed to light the burner. The problem is the burner won't light up again, at least for a good long time.

The operating thermostat is actually just a thermal switch and it is adjustable. There is a screw adjustment to set it anywhere from 140F to 155F (the temperature it opens at). It closes again when the temperature drops by 5 degrees. The idea is that this thermostat switch cycles voltage to the gas valve and thereby maintain the temperature for the dryer.

I suspect the problem is the gas valve is getting overheated. After some time (again, maybe 10 to 15 minutes of non-operation) the thing will light the burner again and once again it heats up and repeats the single heating cycle. As near as I can determine the electrical circuit is working as it should be, its just that the gas valve is disfunctional. Has anyone here had any experience trying to fix one of these?the lighting heat coil is bad & is NOT sending a signal to the gas valve when it is warm , when cold it works .
My repair guy says it's not showing enuff &/OR too much resistance to the gas valve to allow it to open when warm . Yeah I know sounds strange to me as well . replaced the coil & all is well
IF it was just not heating up at all then it's the overheat fuse is open (failed)
try measuring the coil's hesitance cold & then hot if they are quite different then you'll know

Jason Roehl
03-31-2014, 7:28 AM
It could be a bad igniter or flame sensor (sometimes there is a tiny reset button on the flame sensors--the sensors are about 3/4" diameter and will have 2 terminals on them, the reset will be in the center).

Also, make sure that the vent duct is not clogged anywhere along the line (and it needs to be metal, preferably rigid).

Pat Barry
03-31-2014, 7:52 AM
Thanks Guys.

Yes - Jason, I went through the entire machine and cleaned and vacuumed out all the lint so I know the air flow is good. Its all straight metal 4" piping (not corrugated).

I think the flame sensor could be the problem - its mounted right to the burner assembly. It may be opening up too soon. Like I think I mentioned, it does try to re-ignite for a second heating cycle. It might be a bit too sensitive .

I will check the heating coil resistances like you mentioned Mike - that's sounds like a good lead also.

I found the schematic and also took a bad cell phone picture of the gas valve / burner. The flame sensor switch is mounted on the top left side of the burner, right in the middle of the rusty looking area. I wonder if the rusty appearance is typical or indicating a problem?
286161

286160

Jason Roehl
03-31-2014, 9:16 AM
Not just the machine, but make sure all the vent pipe is clean all the way to the exterior. With good venting, the flame will shoot past the flame sensor, not tripping it. If the venting is somewhat restricted (either with lint or too much length or too many elbows), the flame will be shorter and wider, tripping the flame sensor.

Bill Huber
03-31-2014, 10:01 AM
Pat, here is the fix, works every time and I am sure you daughter would love it......:rolleyes::rolleyes:

286171

Jerome Stanek
03-31-2014, 10:08 AM
Pat, here is the fix, works every time and I am sure you daughter would love it......:rolleyes::rolleyes:

286171

We have one of those but the clothes don't dry in the winter when it is 0 out there.

Bill Huber
03-31-2014, 12:31 PM
We have one of those but the clothes don't dry in the winter when it is 0 out there.

That is when you got one of these....

I remember my mom getting the rack out and moving the dinning room table and putting plastic table cloths on the floor under the rack in the winter.

286185

Pat Barry
03-31-2014, 12:51 PM
Pat, here is the fix, works every time and I am sure you daughter would love it......:rolleyes::rolleyes:

286171
She actually has one of those (with a retractable cord) and uses it in the summer months but right now we still have a foot of snow on the ground and piles 4 feet deep

Tom Stenzel
03-31-2014, 1:20 PM
I had this exact same problem with my 3 or 4 year old Whirlpool dryer. It was the gas valve coils.

Google: whirlpool dryer gas coil replacement

and you will find you’re not alone, it's a real common problem Also every local appliance repair shop in my area have these in stock. I bought them locally for $24, it needed fixing Right Now.

If the dryer has the lower removable kick panel the job is trivial. If you don’t:

1. Unplug it before you start.

2. When you go to remove the top remember the two screws under the lint trap.

3. When the front is removed the dryer drum will fall out of place. To stop that, pass a cord around the drum and tie it up to the side panels of the dryer. It’ll stay in place enough so the drive belt won’t pop off, and when you’re putting the front back on lining it up will be easy.

How do you pass a cord under the drum? I tied the cord to a hard drive magnet and stuck it to the drum. Spin the drum by hand one turn, cord is now wrapped under the drum.

To remove the old gas valve coils mine needed a #2 phillips. Because of the stuff in the way, I used a hex drive bit and turned it with a small 1/4" ignition type box wrench around the bit.

Lotsa luck.

-Tom Stenzel

Pat Barry
03-31-2014, 6:43 PM
I had this exact same problem with my 3 or 4 year old Whirlpool dryer. It was the gas valve coils.

Google: whirlpool dryer gas coil replacement

and you will find you’re not alone, it's a real common problem Also every local appliance repair shop in my area have these in stock. I bought them locally for $24, it needed fixing Right Now.

If the dryer has the lower removable kick panel the job is trivial. If you don’t:

1. Unplug it before you start.

2. When you go to remove the top remember the two screws under the lint trap.

3. When the front is removed the dryer drum will fall out of place. To stop that, pass a cord around the drum and tie it up to the side panels of the dryer. It’ll stay in place enough so the drive belt won’t pop off, and when you’re putting the front back on lining it up will be easy.

How do you pass a cord under the drum? I tied the cord to a hard drive magnet and stuck it to the drum. Spin the drum by hand one turn, cord is now wrapped under the drum.

To remove the old gas valve coils mine needed a #2 phillips. Because of the stuff in the way, I used a hex drive bit and turned it with a small 1/4" ignition type box wrench around the bit.

Lotsa luck.

-Tom Stenzel
Tom, thanks for the tip on supporting the drum, I didn't do this Sunday and it was a bear and a lotta luck to get the drum back into the machine (my daughters machine doesn't have the kick panel) . I do need to take it apart again to replace the gas valve coils, so I will be using your tip this time. Thanks for the info.

Keith Westfall
03-31-2014, 11:40 PM
My mom (When I was just a little guy...) used to hang clothes out at sub-zero temperatures and they would freeze hard as a board. You could bring them in one handed standing straight out! But when they came up to room temperature they smelled so nice and were so soft. Guess it worked...