Thermostat Terminals and Connections
Common Wiring Terminals / Connections for Thermostats
| Terminal |
Description |
| |
|
| RH |
24 Volt Hot for Heating
|
| RC |
24 Volt Hot for Cooling |
| C |
24 Volt Common |
| G |
Fan |
| Y or Y1 |
Compressor, First Stage Cool |
| Y2 |
Second Stage Cool |
| W or W1 |
First Stage Heat |
| W2 |
Second Stage Heat |
| O |
Heat Pump Reversing Valve Cooling |
| B |
Heat Pump Reversing Valve Heating
|
Notes:
- C connection is often ommitted by builders but is required for most automated thermostats to power the thermostat. There are ways around this requirement such as 5-4 wire adapter kits, or in the case of some brands like NEST they use an on board battery that is charged during use and powers the thermostat.
- RH and RC may be have a jumper wire between them in some installations