Goodman Furnace: Low stage pressure switch stuck closed at start of heating
Low stage pressure switch stuck closed at start of heating on a Goodman furnace: The board sees the low stage pressure switch closed before the inducer has even started, so it won't go any further and the furnace won't run. The switch should be open when the inducer is off. If it reads closed at rest, it's stuck or something is shorting it.
Applies to: 34.5 in chassis gas furnaces
Common causes of low stage pressure switch stuck closed at start of heating
- Low stage pressure switch circuit closed at the start of the heating cycle
- Switch contacts stuck closed
- Short in the switch wiring
How to fix low stage pressure switch stuck closed at start of heating: step by step
- Turn power off before repair.
- Disconnect the switch leads and check across the switch with a meter. With the inducer off it should be open.
- If it reads closed with the leads off, replace the pressure switch with the correct replacement part.
- If the switch is open, check the wiring for a short.
- Restore power and run a full cycle.
If the unit shows an error code, look it up: Goodman Furnace codes
Source: Goodman GMVC96 Service and Troubleshooting, p. 60. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.