Goodman Furnace: Furnace fails to operate, control LED shows no signal
Furnace fails to operate, control LED shows no signal on a Goodman furnace: Dead board. No LED, no display, furnace does nothing. Start at power, work toward the control. Most of the time it is a tripped breaker, a door switch or a blown fuse before it is the board. Board swap is last.
Applies to: 34.5 in chassis gas furnaces
Common causes of furnace fails to operate, control led shows no signal
- No 115 V power to the furnace or no 24 V power to the control module
- Blown fuse or tripped circuit breaker
- Open blower door switch cutting power
- Failed transformer
- Integrated control module is not working
How to fix furnace fails to operate, control led shows no signal: step by step
- Check 115 V power to the furnace and to the control module with a meter
- Check the blower door switch is pressed in and making
- Check for shorts in the 115 V circuit and repair as needed. A short will keep tripping the breaker
- Measure 24 V at the control. If 115 V goes in the transformer but no 24 V comes out, the transformer is bad
- Turn power off before any repair
- Read the electrostatic discharge precautions in the manual before handling the control
- Replace a non-working control module with the correct part
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.