Rheem
45
LockoutLow PS open at HIGH inducer speed
On VA / Endeavor cards that split low-pressure: the LPS did not close while the inducer is on high. This is not TA ‘45 = all low PS.’
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 45. 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
- Intake pipe, low-fire hose, inducer low, trap.
- Attic intakes ice. This is the Rheem 45 people confuse with Carrier lockout 45.
- Do not treat 45 as ‘all pressure switches’ or as VA high-inducer LPS.
- Confirm the door card on THIS cabinet before you treat 45 as intake/low-fire.
- High-inducer LPS hose, inducer actually on high, vent load at high speed.
- 58/59 first if stored.
- Cap, liner, common-vented water heater, inducer wheel.
- PS hose to the inducer housing.
Plates that use 45
Same number, other makers
45 on Rheem is not the same code on these plates.