Low pressure switch closed with inducer off.
§1Likely causes
- Faulty switch
- Pressure switch bypassed in the field
- Loose or faulty wiring
- Abnormally high negative pressure on vent system
§2Safe DIY steps
- Technicianreplace switch, remove any bypass, check wiring and venting
§3When to call a pro
Call a licensed HVAC technician: this indicates a failed or bypassed safety switch.
Find a local HVAC pro →§4Other Rheem codes
One-hour lockout, caused by repeated failed ignition (11), water sensed (59), dead blower (61), internal fault (93), flame lost 5 times (13) or unexpected flame (14).
11RheemFailed ignition. After four failed attempts the control enters one-hour lockout (10).
12RheemLow flame sense: flame sense current is weak or marginal. Furnace keeps running.
13RheemFlame lost after established.
14RheemFlame present with gas valve off. Extremely critical; furnace will not operate.
30RheemOpen fuse, usually from a 24 VAC short to common or ground.