Dryer Thermal Fuse Keeps Blowing

dryer

I have a Samsung DV42H5000ew and the thermal fuse (DC96-00887A) on the heating element housing has blown twice, most recently one a day after it was replaced.

After it blew the first time, I replaced the high limit thermostat (DC47-00018A) as well as the heating element (DC47-00019A).

Since it has blown again, I have tested the thermistor (DC32-00007A) and got 9.16 ohms. My understanding that 10-11 ohms is normal – is my reading too low to the point that the thermistor is not regulating heat properly?

I tested the thermal fuse (DC47-00016A) on the blower (next to the thermistor) and it has continuity.

The vent and blower are extremely clean, figured I'd find some lint but did not. I have great air flow at the vent cap.

I did discover that the dryer cord was incorrectly wired so far as the ground jump wire from the dryer was wired to the ground of the cord instead of the neutral terminal. I have corrected this mis-wire – is it possible that, after 5 years of normal operation, this wiring issue caused problems that led to the thermal fuse on the heating element housing blowing?

At this point, I can't think of anything else that could be causing the dryer to overheat and blow the fuse. Any suggestions on what else to check?

Best Answer

The dryer has 2 thermistors, one near the heater element. One failure mode, if you have bad seals (they do wear out with age) on the blower or filter cover, such that colder air is sucked into the system, giving that thermistor a lower reading than actual, the control system will keep adding heat to bring up the temp. But, actual temp get hotter and blows the thermal fuse. Replace or repair blower and dryer filter cover seals.