Dryer too hot flips the thermal fuse

Dryer Repair
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1

My issue started with my wife noticing that the dryer was running cold. I then took the following steps:

  1. Checked for airflow outside the house. It was blowing cool air
  2. Used my leaf blower to blow air through the air duct and check for blockage. Very little came out.
  3. Checked the hose. Not perfect, but nothing visible clogging it. It does have to snake around creating two turns, but it has been like this for a while with no issues.
  4. Checked the element. No breaks. Nothing touched the metal housing. Element has continuity.
  5. Checked the thermostat and thermal fuse (the two fuses on the element housing. Not sure the technical names.) The little one (thermal fuse) has no continuity the bigger one was fine. I figured it must have been tripped.
  6. I replaced the thermal fuse. Dryer worked for five minutes. Seemed to run hot. After five minutes it turned cold. Checked the new thermal fuse and it was tripped.

For some reason the element is overheating the dryer and tripping the fuse. I then did a continuity with one end of the element and directly on the housing to test for a ground issue and got no continuity. Which is good, correct?

At a loss at what to do now? Is it worth replacing the element (just replaced this summer) if everything is testing out with it? Is there another fuse or thermostat somewhere? Can the other thermostat be an issue if it has continuity?

Thanks in advance

3

There is a high limit t-stat on most dryers that should limit the heating. This is one you may need to find and check. Usually the thermal fuse trips because of a restriction in the outlet vent tube. Suggest you runs the dryer with the vent tube disconnected completely after you replace or bypass the thermal fuse.

4

The high limit has continuity. Also I bypassed the thermal fuse and ran it. The outgoing air measured 165 then down to about 135 then up again. Cycle five or six times. Is that range OK? Currently assuming the problem was the hose partially blocked. Just hard to believe since it didn’t look too bad. Any thoughts?

5

Maverick1 said:
The high limit has continuity. Also I bypassed the thermal fuse and ran it. The outgoing air measured 165 then down to about 135 then up again. Cycle five or six times. Is that range OK? Currently assuming the problem was the hose partially blocked. Just hard to believe since it didn’t look too bad. Any thoughts?

That temp is about right based on some testing I did on a dryer recently. The thermal fuse blows when the air flow is blocked or significantly restricted. I changed one today and the amount of stuff in the blower air flow was considerable.