We have a Carrier 58STA/STX Furnace that is only short cycling in Heat and not A/C. When it cuts off it is throwing Code 33 which is pointing to the following issues:
- Dirty Filter or Restricted Duct System - Replaced Filters & Using a MERV 2, still trips
- Loose Blower Wheel - Removed today and was not loose/excessive play
- Defective Switch or Connections
- Defective Blower Motor or Capacitor - Capacitor was at 50% of nominal, replaced and still occurs, have not done anything with blower motor.
- Inadequate Combustion Air Supply (Flame Rollout Switch Open) - Flame Rollout Switch stays closed
- Restricted Vent Sizing - Spec'd to House
- Excessive Wind - Happens on Windy or Calm Days
If I either remove the filter or remove the blower access cover it does not throw the code.