Alexander for Model Number WTMC3300US/01 Hi, I'm having an issue where the hi-limit thermal fuse (at the heating element) keeps tripping. It started as once every few months, but has progressed to the point where it's happening weekly. I have the service manual for the dryer and have conducted some testing, the results of which I'll summarize below: - Heating element has continuity; resistance at room temp is about 10 kO which I understand is within spec - Hi-limit fuse (resettable) at the heating element opens at about 190°C; this is repeatable and seems to be within spec - Measurement of resistance for NTC R3 (at lint screen) across range of temperatures produces accurate readings, so I don't think this is the issue. Furthermore, the hi-limit fuse (single use) at the lint screen has continuity and has never tripped - Resistance values for NTC R2 (at heating element) seem to deviate more significantly from the values specified in the service manual. For example, specified rating at 50°C is 7.2 kO, but I'm reading ~ 8.5 kO. At 100°C, spec is 1.3 kO, but I'm reading closer to 2.2 kO In summary, since the element has continuity, I don't really see what else could be wrong with it. (Please let me know if I'm mistaken!) That leaves either the NTC's or the hi-limit fuse as the culprit, and since NTC R3 and the fuse seem to test okay, I'm thinking NTC R2 is to blame. This would make sense as the temp is reading low, so the element may stay on longer and reach the hi-limit threshold... It *seems* like replacing NTC R2 would solve this problem, but I'm sure there are other possibilities too. I don't know how common drift is with these sensors. If there's any chance of the hi-limit fuse or the element itself being the issue, I'd rather just replace the whole assembly than the individual parts, as it includes these things with it. Thanks in advance!!!
Answer Alexander, the R2 NTC 00422221 is certainly going to cause problems as it would cause the heater to stay on longer than necessary. This could cause the element to get too hot. Another thing that could be occurring is that the heating element 00436460 could be heating up enough to start sagging and grounding out to the element casing. Usually, when this occurs, there is an indication of a temporary weld spot on the casing itself or the element stays grounded and would have continuity to the casing. Read More... Answered by AppliancePartsPros.com | Wednesday, February 19, 2020