Yesterday my wife mentioned that the Ex Low setting was way too hot.

Exhaust duct is clean.
Element is not shorted or open
Exhaust seal is good and blower is clean
Thermal Fuse good
High Limit Good.
Cycling thermostat tests good. (Same symptoms with second thermostat)

I just tested with a thermometer at the exhaust duct.

On Air Only the heater does not engage.
On the other four settings Ex Low, Low, Med, Hi the results are the same.
Starts at about 110 degrees, Climbs to 150 degrees and then slowly drops back to 110. Repeats.

I have tested everything that has been recommended .

Any ideas?

Thank You