Rheem Furnace Code 44
Safety fault
Low pressure switch closed with the inducer off. The low pressure switch is proving closed before the inducer even starts, which it should never do. The control tests for this before every heat cycle. The manual warns the switch may be welded closed or deliberately bypassed in the field.
Manual wording: “LOW PRESSURE SWITCH CLOSED, INDUCER OFF ... 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.”
Documented for: (-)97V, (-)96V
Likely causes, most common first
- Faulty switch
- Pressure switch physically bypassed in the field
- Loose or faulty wiring
- Abnormally high negative pressure present on vent system without inducer running
When to call a technician
Technician only. This is a combustion-safety interlock that is not doing its job - it must be replaced or the field bypass removed, never left in place.
A Rheem furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installation Instructions for Upflow Condensing Modulating, Communicating Gas Furnaces - (-)97V Series (92-24161-126-04) (Rheem Manufacturing Company, R97V series modulating condensing gas furnace (and R98V); TABLE 18 normal operation codes, TABLE 19 fault codes, pages 94-104) · checked 2026-08-25
- Installation Instructions for 4 Position Condensing Two-Stage, Communicating Gas Furnaces - (-)96V Series (92-24161-124-08) (Rheem Manufacturing Company, R96V series and (-)(-)96MDV two-stage condensing gas furnaces; TABLE 19 normal operation codes, TABLE 20 fault codes, pages 111-120) · checked 2026-08-25