SeanMac769tj
Jan 26, 2011, 03:27 PM
Hi, I am trying to replace an old manual thermostat with a Honeywell RTH221 digital. The problem is I have 3 wires Red, Black, and White. When I touch the Black and White in anyway the heater turns on. I have no idea what the Red wire does seeing as it was not even hooked up to the old thermostat. If anyone has any suggestions that would be great. Thanks