Scatter, your old thermostat has some interesting wiring going on. Here’s what I am able to look at from the picture and determine. You have two separate thermostat cables coming to your old thermostat. It looks like you have a HEAT PUMP System along with your OIL Burner furnace.
What we do not know is the programming of the old thermostat. Can you provide me the manufacturer and model number of the old thermostat? It looks like a White Rogers.
Let’s try to understand this.:
W2 - Heating Stage 2
W/E - Heating Stage 1, or Heat Pump Emergency Heat
6 - 24VAC Output from Heating Transformer
RH - 24VAC input from Heating Transformer
RC - 24VAC input from Cooling Transformer
C - Common
L - Light (typically the emergency heat on lamp)
O/B - Heat Pump Reversing Valve.
G - Indoor Blower Fan
Y - Stage 1 Cooling
Y2 - Stage 2 Cooling
Let’s take them one at a time. W2 seems to have two wires in it; Looks like a White Wire and a Black wire. A red wire going to Rh. A second white wire going to W/E. A Jumper wire between 6 and Rc. A black wire in O/B, a green wire in G and and an orange wire in Y. The 6 terminal sends the Rh power to the RC.
Please tell me how your old thermostat used to operate your heat and cooling. Also, can you go outside and take a picture of the manufacturer label showing the model number and serial number of the unit that’s outside please and uploaded here. I like to verify that you have a need a heat pump.
Ken, The Cooling Wizard
NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
