I just installed a Honeywell T-Stat with their wire saver module. Install was simple everything hooked up according to their diagram, Verda3 found the unit. But when I run AC, it runs AC and Gas furnace at the same time. Any ideas? T-Stat setting maybe?
Go into settings on the thermostat and change setting 0170 to 1 its probably set at 7
Im assuming you have single cool and single heat.
Some of the Honeywell thermostats also have a jumper for heat-only systems. The jumper gets removed if you have heat and A/C. I fell for that once, and you never fall for it again…