Rheem R801SA furnace code 57: Pressure switch open
Professional repair
What does code 57 mean on a Rheem R801SA (801S downflow) furnace display? Code 57 means the pressure switch stayed open when the control expected it closed. If it does not close within the 60-second proving period, the furnace enters a five-minute soft lockout.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
Safe checks before calling
From the ground, look at any vent or air opening you can see safely for snow, ice, nests or debris. Do not climb to the roof or remove any pipe or hose.
A technician tests inducer operation, pressure readings, hoses, venting and switch wiring. The switch itself is replaced only if testing shows it fails with correct draft present.
Possible causes
- Inducer motor not creating enough draft to close the switch TECH
- Kinked, blocked or disconnected pressure-switch hose TECH
- Vent restriction or leaking gaskets affecting draft pressure TECH
Parts for this code
No model-verified part number is listed here. Have the fault diagnosed and the correct part matched to your furnace before ordering.
Questions about this code
What does code 57 mean on a Rheem R801SA (801S downflow) furnace display?
Code 57 means the pressure switch stayed open when the control expected it closed. If it does not close within the 60-second proving period, the furnace enters a five-minute soft lockout.
How do I fix Rheem R801SA furnace code 57?
Book service with the code recorded, and mention anything you saw blocking an accessible vent opening. The furnace may retry after the five-minute lockout, but repeated retries do not correct the cause.
How much does it cost to fix Rheem R801SA furnace code 57?
Diagnosis covers the inducer, hoses, venting and switch circuit. Clearing a blockage, reconnecting a hose and replacing an inducer are very different labor jobs.
Applies to
R801SA / 801S downflow single-stage 80% furnace with PSC motor
Different Rheem generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against Installation Instructions for Downflow Single Stage Gas Furnaces, p.34
Verified against Rheem 801S Series Installation Instructions — OEM143-14 mirror, p.34
Verified against Rheem 801S Series Installation Instructions — OEM143-14 mirror, p.35
Verified against Rheem 801S Series Installation Instructions — OEM143-14 mirror, p.43
Last verified 2026-10-07 · page updated 2026-10-07 · how we verify
Related Rheem furnace codes
These codes use the same rheem 801s downflow single-stage control (manual 92-24161-143-14) system.