sparkhvac
10-01-2011, 09:45 AM
ISSUE: Thermostat seems to be sending fan and cool on AC request and is overiding the furnace board settings of cool delay.
EQUIP: Furnace board - Honeywell ST9120B,U; Thermostat - Honeywell RTH8500
ASK: Can I configure this to have the board control the fan and not the thermostat without removing the G wire.
DETAILS:
I recently had my furnace board replaced and have an issue with the COOL ON DELAY. Before this new board there was a 30 second delay. The new board supports this and I have set the DIP settings to 30 seconds, however the fan now comes on instantly when it calls for cool.
If I remove the G wire the process works fine (so it appears that the thermostat is sending for the fan on AC). I am not sure why this worked on the old board, but I don't want to leave the G off as I like to run the fan all the time.
Thanks!
EQUIP: Furnace board - Honeywell ST9120B,U; Thermostat - Honeywell RTH8500
ASK: Can I configure this to have the board control the fan and not the thermostat without removing the G wire.
DETAILS:
I recently had my furnace board replaced and have an issue with the COOL ON DELAY. Before this new board there was a 30 second delay. The new board supports this and I have set the DIP settings to 30 seconds, however the fan now comes on instantly when it calls for cool.
If I remove the G wire the process works fine (so it appears that the thermostat is sending for the fan on AC). I am not sure why this worked on the old board, but I don't want to leave the G off as I like to run the fan all the time.
Thanks!