Cold and Wet

About a year after our washing machine stopped washing, our old Kenmore electric dryer (110.62972101) stopped drying (with a full load of wet laundry, of course, because how else do you find out a dryer isn't working...). The motor and drum were still working - but the heating element was not doing anything. Fortunately we have lots of drying racks (and our house is very dry in the winter) so we were not immediately screwed. But with a very messy baby, the laundry pile grew very fast.

So we were left with three choices: buy a new dryer, call in a repairman, or fix it ourself. It would take a week to deliver a new one and over a week to get a repairman. A replacement would cost over $800 and the repairman was $65 to show up and $20 for every 15 minutes after that. Parts extra. I would guess at least an hour to fix. So with parts, approaching $200 for repairing a very old machine.

So we decided to spend a day or two trying to Google-fix the dryer and if that failed, we would order a new one.

Googling suggested a few things that were easy to check: first that the fuse partially blew and second was that the exhaust vent was clogged. Dryers have a thermal fuse sensor that stops the dryer if the heat gets too high. But the vent was flowing just fine (which we expected, since we'd recently cleaned it out). Next we opened up the bottom front panel to check a series of fuses and sensors that control the temperature of heating element and when it turns on. Opening it up was easy to do since I had done it a couple of times already.

There were a couple of sensors immediately visible after removing the shield.

I believe the left sensor is the aforementioned thermal fuse, which tests whether the exhaust air is getting too hot (i.e. the vent may be clogged). I think the right sensor is a cycling thermostat which controls how long the heating element is left on. After pulling the plug on the dryer (220 volts!), I disconnected one wire each from the sensors and checked for continuity with my multimeter. But these two and the two I found jammed way on the inside next to the heating coil were all fine. So next I checked the heating coil, which was hidden behind an annoying-to-remove metal panel. After a fair amount of swearing I had it visible.

Unfortunately this was also working just fine. I was left with a series of difficult to check things: maybe the motor was not sending power to the heating element. Or perhaps one of the electric panel switches was not sending the right signal. Checking the motor would be really hard because it is located behind the ducting for the exhaust. Checking the switches at the top of the dryer would be scary because they would require the power to be connected. I made one brief attempt to check continuity at the heat switch, but quickly gave that up after a live wire accidentally brushed another piece of metal (nowhere near me!) and gave off a huge spark.

Mess of wires underneath the controls

I was resigned to order a new dryer when I realized that the switch that controls the heat is identical to the switch that controls whether the dryer should run or not.

So I just swapped the two switches and was happy to find out that now the dryer would only run if you held down the "Start" button. After holding the button down for a few seconds it was obvious that the heat was working! So I overnighted a new switch from Amazon and after a few minutes of swapping wires, we had a functional dryer again.

The culprit

2 hours and $20, not bad!