Samsung model DV5471AEW/XAA electric dryer.

My dryer runs but doesn't heat. It did this before, and randomly started heating again a few days later, but this time it seems to have quit heating for good. The ducting is a straight, smooth-sided duct. It's a straight shot outside, no bends.

The heating element shows continuity across the 2 spade connectors. The thermal fuse on the heater assembly shows continuity as well. The high-limit thermostat shows continuity at room temp, and disconnects between 255 and 273 Fahrenheit (I tested several times on electric griddle with digital thermometer) with 250-50F stamped on its housing. I also tested the outlet, got about 124 volts on each slot.

I've removed the drum to get to the other sensors. I tested the thermistor on the blower housing, and it has a resistance of just over 10k ohm, which is what it should be (according to info I found online).

The last thing I could find to test was the second thermal fuse, that's on the blower housing. It tested fine, with continuity.

I'm not sure what else to check. Any help is appreciated.

It seems to have worked, I started it for a minute and felt hot air, before reconnecting the vent duct. Washing a load right now, to do a real test with laundry.

In case someone finds this in a search later, I resolved the problem, it was the thermistor.

When completely cold, the dryer would run with heat for maybe 1 minute, then the heat would stop (but the dryer would keep running the rest of its cycle). I read that the thermistor is a resistor that changes resistance based on the temperature, so I figured it was failing after heating up. I changed it ($7 part), and it runs perfectly now.