Goodman Furnace: Condensate switch open
Condensate switch open on a Goodman furnace: The furnace won't run because the condensate switch is open. The switch trips when water backs up in the drain pan or trap, and the board shuts the furnace down so it doesn't overflow. Check the drain before blaming the switch.
Applies to: 34.5 in chassis gas furnaces
Common causes of condensate switch open
- High water level in the evaporator coil pan
- Plugged trap or drain line
- Drain line kinked or not pitched away from the unit
How to fix condensate switch open: step by step
- Turn power off before service.
- Check the evaporator drain pan, trap and piping.
- Clear any slime or debris and flush the line with water. Make sure it slopes down to the drain.
- Refill the trap if the unit has one.
- Restore power, run it, and confirm water is draining and the switch closes.
If the unit shows an error code, look it up: Goodman Furnace codes
Source: Goodman GMVC96 Service and Troubleshooting, p. 62. 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.