Samsung Dryer Keeps Blowing Thermal Fuse

Dryer Repair
1

Have a Samsung dryer that’s a few years old, Model No. DV218AEB.

The dryer no longer heated up two days ago, so I took the dryer apart and checked for blockages, tested everything with a multimeter for continuity and shorts, and found the thermostat cut-off had blown. Everything else tested within spec and there were no shorts or any visually obvious issues.

Replaced the thermostat cut-off with a new one (Samsung Part No. DC47-00016A) and put it back together. Dryer heated up fine the first time it was turned on and run for a minute, but then apparently blew the thermal cut-off immediately the second time it was turned on, since it no longer blew hot air again.

I took the dryer apart again and replaced the high-limit thermostat (Samsung Part No. DC47-00018A) at the heating element even though the original tested good. Put the dryer back together, again, worked fine when turned on and run the first time, heated properly, but blew cool air the second time I turned it on.

Just throwing this out there to get any ideas on what to check or personal experiences on what causes dryers to blow thermal cut-offs like this so I don’t keep throwing parts at it. I’m at a loss since there is nothing obvious and looking up the common causes online has only revealed causes such as blocked vents or the high-limit thermostat.

There is NO blockage anywhere, dryer is extremely clean and there was almost no lint buildup at all, the vent system goes straight out an unrestricted 4-inch pipe.

I’ve taken apart the element assembly, the element looks great, has the correct ~10 ohms reading at room temp, and is not touching the housing or any other metal when assembled (verified with multimeter). The thermistor reads the correct ~10K ohms at room temp, and goes to ~7K ohms when warmed and about ~15K ohms when cool. The second thermostat cut-off (right after the blower, next to the thermistor) has not blown and shows continuity.

The motor runs fine and is getting 120V, and the heater relay seems to be working and getting 240V since the element heats up, at least once the dryer is first started up after replacing the thermal cut-off.

Thanks in advance for any helpful replies.

2

Checked the relay on the board with the blue/black wires disconnected, no continuity across the contacts.

Also checked all the wires in the heater circuit (red, blue, black) for continuity and for shorts to ground. Everything checks good.

I connected the two wires that go to the thermal cut-off to bypass it for testing, made sure they had continuity and that everything else in the circuit had continuity and wasn’t shorted to ground. Put the dryer back together and ran it for several minutes on both normal and timed dry/high heat modes to check the exhaust temperature and heat cycling.

Checked the exhaust temp and heat cycling with both a 200*F meat thermometer at the exhaust vent and a non-contact infrared thermometer. The meat thermometer seemed pretty dang accurate, even more so than the infrared, which showed about 10-15 degrees less than the meat thermometer, even when held very close to the vent and pointed at the inside walls. Guess they really aren’t so great for checking air temperature.

Did the first run on “normal” cycle (which seems to use the moisture sensor) it went up to ~140-150*F on the meat thermometer and stayed there, showed slightly less on the infrared. The dryer stopped automatically on it’s own after about 2-3 minutes.

Did the second run right after, on the “timed dry” cycle, with highest heat setting selected. It took a minute to get up to 140F, then climbed to 150F after another minute, then slowly went to 160F, then 170F, and backed off, taking only 10-20 seconds to go all the way back down to 140F, where it held for another 10-20 seconds, then slowly climbed to 150F again, then 160*, and finally 170F, where it stayed for a 10-20 seconds, then backed off again all the way to 140F.

So, two complete cycles getting up to 140F, going all the way to 170F, and back down to 140*F.

I guess this means the thermal cycling is okay and the cut-off isn’t blowing because of high heating element temps.

What else blows a thermal cut-off?

3

We are having the same issue, what if anything did you find?

4

I’m experiencing this very issue and have gone through similar steps to troubleshoot and clean. Have any of you been able to resolve?

5

Was there ever a resolution to this issue having the same issue

6

I had the issue with the Samsung dryer element components continuing to failure after replacing them. I found that I had to run the dryer on “ no higher than medium
heat setting “. The medium setting will dry the clothes as efficiently as the old high setting and the failures will stop. It has been running for several months now without failure.

7

I had the issue with the Samsung dryer element components continuing to failure after replacing them. I found that I had to run the dryer on “ no higher than medium
heat setting “. The medium setting will dry the clothes as efficiently as the old high setting and the failures will stop. It has been running for several months now without failure.

8

having same issue, Dryer quit heating, tested heating element and no continuity. Checked other to switches and have continuity. Replaced heating element and now thermostat cut-off blew. Put a new one in and it blew too?

9

I had the same issue , and I believe that is either the thermistor or the heating relay on the board got stuck closed , I think Samsung is still learning how to build appliances , th3 owner of the house decided to buy a new dryer