Carrier
Draft / PS lockout
HazardWill not prove / fails combustion
On this family that is often a restricted secondary, not a 59TP6 trap lecture alone.
Walk Draft / PS lockout in Diagnose
Sign in for the next measurement
First check
1 Prove inducer and the live code
Do not pull power — that clears the Carrier 58MCA active code. Write Draft / PS lockout. Is the inducer spinning on this call? Silent inducer is not a pressure switch. Serial in 2993A00001–1808A99999? If no, this bulletin does not apply — treat as a standard 90% draft call.
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
- Serial in 2993A00001–1808A99999? If no, this bulletin does not apply — treat as a standard 90% draft call.
- Visual secondary / coupling box per the Carrier inspection sheet. Do not punch holes in the secondary to ‘test.’
- Combustion analysis if it still fires. Failed CA + restriction = bulletin path.
- CO / rollout: shut it down. This is a hazard call until the secondary is proven.