A044_F: Low Press Switch Won't Open
Status
This is a critical fault. The furnace will not operate in gas heat modes but all other modes (e.g. cooling) should function if present simultaneously with a heating call (e.g. defrost call in dual-fuel mode).
Description
The low pressure control (or switch) should not be closed when the inducer is not running. If it is, this is a sign of a serious condition. The switch may be welded closed or purposely bypassed in the field. Before any heat cycle can begin, the pressure switch is tested to make sure that it is opened. The switch is ignored except in gas heating modes.
Expected Operation
Gas heating will not be allowed. Alarm "A044_F Inducer Low Pressure Switch Won't Open" will be logged if a heat demand is present.
Solution
1. Replace low pressure control (switch).
2. Remove bypass (jumper) and restore correct operation. Determine reason for jumper (e.g. vent length too long) and correct issue. Notify homeowner and proper authorities of any illegal tampering if necessary.
3. Check wiring and connections. Replace and/or repair as necessary.
4. Check for proper venting and terminations as defined in the furnace installation instructions.
