Rheem
57
LockoutHigh pressure switch OPEN
High-pressure / exhaust switch open.
Walk 57 in Diagnose
8 plates — walk the one on the cabinet
First check
1 Prove inducer and the live code
Do not pull power — that clears the Rheem R801S active code. Write 57. Is the inducer spinning on this call? Silent inducer is not a pressure switch. This is Category I metal vent. There is no 96% collector or PVC trap to prime.
Expect: 120 VAC at the inducer on a heat call. Wheel turning.
If fail: 120 VAC missing → IFC / door switch / incoming power. Voltage + dead motor → inducer.
If pass: Inducer running + this code → trap, hose, switch, vent (step 2).
The rest of the walkthrough is Diagnose.
On the plates
- Exhaust termination, high-fire hose, inducer high speed.
- 45 then 57 together: shared collector/vent problem, not two switches.
- Exhaust, high-fire hose, inducer high.
- 46 vs 45 vs 57 are three different moments — write the order.
- Inducer, hose, chimney capacity.
- On two-stage 80% this split is the R802V story — confirm you are not on that cabinet.
- Inducer actually goes high? Chimney capacity on high fire.
- High-draft hose, not teed to the low switch.