Whirlpool Dryer Overheat. Lots of diagnostics and parts replaced

Dryer Repair
,
1

I originally put this in someone else’s thread but it’s officially become a "fix it or buy a new one" situation and the dryer isn’t that old.

I replaced the heating element, both "thermostats" on the element housing, and the "thermostat" next to the thermal fuse. I also replaced the heating element, which was fine according to resistance checks.

The heating element does not cut off. I suspect that is what knocked out the 1st thermal fuse (and 2nd, 3rd, and 4th) which is what started me on this adventure.

I have the lower cover off and when I run the dryer in Air Only the heating element glows and (of course) the dryer gets very hot if I let it run. Eventually it would trip the thermal fuse if I let it.

I put the dryer in diagnostic mode and no matter what I do, I get the same three error codes.

1- Primary Control failure :mad:
30- Restricted Air Flow Condition
70- No Communication Between Electronic Assemblies.

Air flow test and all of the tests Heat Won’t Shut Off section (4a, 4b, 4c) pass.

Since it looks like the Primary Control is toast I’m going to ignore 30 for now. 1 and 70 seem to indicate that I need to order a primary control assembly. It’s a couple of hundred bucks so I want to be sure nothing else can cause this (not very optimistic there is btw)

Thoughts

3

By replacing the cycling thermostat you’ve ruled that out and if you get heat in air only cycle the air flow is irrelevant. It sounds as if the relay switch on the control board is fused closed or a computer part is telling it to stay closed, allowing current to the heating element always.

4

brobriffin said:
By replacing the cycling thermostat you’ve ruled that out and if you get heat in air only cycle the air flow is irrelevant. It sounds as if the relay switch on the control board is fused closed or a computer part is telling it to stay closed, allowing current to the heating element always.

That’s the conclusion that I came to. The control board is on the way. I’ll find out sometime later this week.

5

Only one other thing would allow it to heat in air flow mode. If the heating element is shorting out against the case. Do a continuity check between element and case… just a final thought

6

brobriffin said:
Only one other thing would allow it to heat in air flow mode. If the heating element is shorting out against the case. Do a continuity check between element and case… just a final thought

I checked that with the old heating element, found nothing, and replaced it anyway. I checked the new one too.