[Foghorn]

Originally Posted by Foghorn

Ok guys, I went to check the cycling of the heating element but before I did I checked the the Thermistor--it is open. I have one on order and will let you know what happens when I get it replaced.

I now have a new dilema. I received the new thermistor but both terminals were bent over so before straightening them out I checked to see if the part showed good with the meter. It read "open" so I contacted the parts people and they sent me a new part. This one arrived in good physical condition but when I put the meter on it it also reads "open". According to the tech sheet I should be getting a reading of about 10 ohms. Am I reading the tech sheet wrong or something or am I receiving bad parts? At this point I hesitate to put put the part in and burn out another thermal cut out. Your help is greatly appreciated.

[denman]

I think you read the tech sheet wrong.
Should be 10 Kohms or 10,000 ohms.

[Foghorn]

Originally Posted by denman

I think you read the tech sheet wrong.
Should be 10 Kohms or 10,000 ohms.

You are correct, I did miss the "K". My "Fluke" meter reads OL but when I put my little cheapie on Rx100 I get a reading of about 100 so it looks like the parts are good---correct? That being said I will check the temperature of the dryer exhaust and try to do a visual to see if the element is cycling.

[denman]

correct?
Correct.

Your Fluke probably gives an OL because you are using a too low scale.
Set it to the 20K scale if it has one and it should read the resistance.

[Foghorn]

Originally Posted by denman

correct?
Correct.

Your Fluke probably gives an OL because you are using a too low scale.
Set it to the 20K scale if it has one and it should read the resistance.

I put the original thermistor back in the machine since it tests good and ran the machine for 5 or 6 minutes. At about 4 minutes the heating element cycled off and back on about a minute later. I didn't continue to run the machine since nothing has changed and I think we will just burn out another thermal cutout. Any more ideas on where to look?

[denman]

Your problem is intermittent so you are stuck just replacing parts until you find the right one.

You have checked the vent system and the heater and both came up OK.
So next on my list would be the thermistor. I would use the new thermistor.
This is based on cost more than anything else.

Next would be the control board as Simon said.
It could be the heater relay contacts are sticking closed once in a while or the electronics that control the relay are going bad.
When relay contacts start to pit due to use they often want to stick together.

[Foghorn]

Originally Posted by denman

Your problem is intermittent so you are stuck just replacing parts until you find the right one.

You have checked the vent system and the heater and both came up OK.
So next on my list would be the thermistor. I would use the new thermistor.
This is based on cost more than anything else.

Next would be the control board as Simon said.
It could be the heater relay contacts are sticking closed once in a while or the electronics that control the relay are going bad.
When relay contacts start to pit due to use they often want to stick together.

Ouch! I was afraid we were down to that. At $184 to $191 for the control boards I will be looking for a new dryer for my grandaughter. Thanks for all your expert advise and help. I will be sure to "pick your brain" the next time I get stumped.

[denman]

OK since you have decided to scrap it, you may want to try a last ditch effort to save it.

Open up the heater relay on the control board and check/clean the relay contacts. Usually cleaning will fix the problem in the short term but for a permanent fix the relay must be replaced.
Getting it open can be a pain.
A dremel with a cutting head should let you cut off the cover just above it's base plate. Getting in there may not be possible. You just want to cut through the plastic, cutting too deep will destroy the relay.
Most relays are sealed but still check to see if the top will pop off.

Often easier just to remove (un-solder) the relay from the board and then open it up.
Before doing anything get manufacturer numbers etc. off the relay.
Then if the contacts are shot you may be able to hunt down a replacement relay.