HVAC Questions? Ask an HVAC Expert for Answers ASAP
This is a limit situation. The furnace is running hotter than designed and then shuts down to cool.
furnace too big for the duct work.
dirty ac coil
bad blower or weak blower.
Pretty much anything that restricts air through the furnace.
You can get parts from any local Heil or Tempstar dealer and also online.
Have you reached into the squirrel cage with power off and felt inside the fins?
If the curve of the fin is not concave...and leveled off with dirt.dust,,this drastically cuts airflow. The fins cut through the air instead of scooping.
I would recommend remove the blower and clean first.
Not usually but it can keep too much heat in the furnace...commonly this slow flow would fault the pressure switch....but it can be somewhat restricitve and still prove flow.
My bet is still on the main blower or wheel.