Stop using dielectric grease on dryer thermistor connections

Saw a guy at a shop in Portland last month load that stuff up. Two weeks later customer calls back. Dryer won't heat. Pulled the thermistor and the grease had turned into a semi-conductor. Messed up the resistance reading completely. These are dry connections folks. No moisture in there. Just put them together clean. Has anyone else seen weird failures from this?

3 comments

3 Comments

faith_king1mo ago

Dielectric grease is non-conductive, so if it turned into a semi-conductor something else was going on there, maybe a chemical reaction with a bad part or moisture that was already trapped. I've used it on thermistors for years with zero issues, just a tiny smear to keep corrosion off the pins.

joel_martinez1mo ago

Yeah totally agree with @faith_king, the whole "it turned into a semi-conductor" thing sounds like someone had a bad batch of grease or contaminated it with something. I've seen people store that stuff in dirty garages where it picks up metal shavings or dust over time, then blame the grease when it starts conducting. Also worth noting that some cheap dielectric greases have filler materials that can break down over heat cycles, but the real good stuff stays inert. The application method matters too - a tiny smear like you said is all it needs, not a full coating.

olivia3981mo ago

Have you guys considered that maybe the grease itself isn't the problem but the way people apply it? I see a ton of folks globbing that stuff on like peanut butter when you really just need a microscopic layer. It's meant to fill microscopic gaps, not sit as a thick paste between contacts. If you put enough on to squeeze out the sides when you push the connector together, that's way too much.