4 replies to this topic

[whimsey]

Hi Samurai-

I wrote to you on the old forum site, regarding my overheating 3.5 year old Frigidaire dryer (scorch marks on the back panel, which was hot enough to burn on contact).  You suggested that it might be the cycling thermostat, and sent me to repairclinic.com for confirmation. The repair guru wanted me first to open the dryer and make sure there were no blockages, which I did, and then suggested it was a shorted heating coil.  On that advice, I replaced the heating coil yesterday.  The temperature of the rear panel does seem to have dropped somewhat-- now I can leave my finger on the back panel for a few seconds before I have to remove it, but it still gets pretty hot.  Is this normal?  How hot should I expect the outside of the dryer to get during normal (safe) operation?  I want to make sure I'm not running a safety hazard.  For what its worth, I did also try replacing the cycling thermostat, but that had no effect.  Thanks in advance for any advice.

Whimsey

[Samurai Appliance Repair Man]

Did you run the dryer with the vent completely disconnected to see if that had any effect?

[whimsey]

Yes--that was the very first thing that I did.  Disconnecting the vent had no effect on the back panel temperature, and there is definitely hot, moist air coming out of the system.

[Samurai Appliance Repair Man]

If I were there at the service call, I'd check to make sure that the heating element is cycling properly.  That is, it should turn on to heat the exhaust temp to about 165F and then cutoff completely until the exhaust temp drops to 145F at which time it turns on again. 

The best way to evaluate this is to measure the voltage at the heating element terminals while it's cycling, should vary from 240v when on to 0v when off. 

Sometimes, in these situations, I see the voltage go from 240v when on, to 120v when "off," which indicates that one side of the heating element power circuitry is staying on.  A stuck centrifugal switch i the motor will cause this.  You may also see the 120v at the heating element terminals when the dryer is plugged in and not running-- this again would indicate a bad motor centrifugal switch.

[whimsey]

Thanks Samurai-- I will take a look at the voltage.  Out of curiosity, can you tell me how hot the back of the average dryer does usually get during normal operation?  Strangely enough, I never thought to touch the back until I noticed the burn marks on this one.  Do they usually get hot enough to make you uncomfortable, or should they be just slightly warm?