Hello,

I have a 2-stage heat, one stage cool heat pump. I am trying to wire this thermostat but it is not working. I called a professional and she told me to wire it as follows, but the heat will never kick on no matter how long I wait.

Left Side Heat Pump
Y2-No wire
L-No wire
E-No wire
AUX-White wire
S1-No wire
S2-No wire

Right Side Heat Pump
RC-Red wire, jumper connected to R
R- No wire, but jumper
O/B - Orange wire
Y-Yellow
G-Green
C-Blue

I have a Black and Brown wire doing nothing. Please help I have tried everything I can think of. Thanks in advance.

I don't know much about heat pumps, but maybe can help you figure it out. The wiring on the right side looks typical. On the left side, likely the white wire needs to connected to whatever the thermostat switches power to when it calls for heat. Y2, S1, and S2 likely are the second stage cooling and outside temperature sensors. Aux is likely the second stage heat cycle. That leaves E and L which I am unfamiliar with. I would check for 24 volts between them and the blue connected to C. You could also try jumpering the red and white wires and see if that starts a heat cycle. You may be able to confirm this in any instructions that may have come with the thermostat. The air handler may have some instructions on it giving clues like that the O/B switches the reversing valves to heat mode, and W starts a heat cycle. If you have E. L, or aux at the air handler, you might try connecting the unused wires to the same terminals at each end.

Still can't get it to work, had a hard time following your suggestions.

Different brands of equipment use different labels for the functions. To heat, the heat pump needs two signals. One sets the reversing valves to the heat position. The other starts the unit up when the thermostat calls for heat. I doubt anybody here can tell you how the terminals are labeled at the air handler and thermostat. You will have to find specific instructions for your unit. You should have received installation instructions with the thermostat. Often there is instructions on the air handler. You can also check the manufacturers web site. Can you identify which terminals did what with the old thermostat?

Sure

W2=White
Y=Yellow
O/B=Orange
G=Green
C=Blue
R=Red

What you need to do is to identify what the W2 terminal did, was it hot when the thermostat called for heat? Then try try to identify which of the E or L on the new thermostat does the same. Either the instructions that came with the thermostat, or the Honeywell website should have that information.

I think I figured it out. I didn't initialize the thermostat right. I feel like an idiot. Thanks for your help Labman.

Glad to hear it. I don't have all the answers. Sometimes the best I can do is point people in the right direction. Your report may help some of the other people here needing help.

I tried installing my Honeywell TH8110U1003 Vision Pro Digital Thermostat. Unfortunately the device does not work for me. I had earlier Honeywell's PRO 4000 Programmable Thermostat.

I thought to replace this with the new one as my old was damaged by me from top though working fine.


I installed Provision yesterday night and tried doing whatever I could do but my heat is not at all getting on.

Here is what I did:

(I) Installed the thermostat back cover.
(ii) Connect the both red wires, yellow and white, green wires, as these were connected in my PRO 4000. I did the same setting what I had earlier so removed the company installed jumper from two reds as I have cooling compressor separately installed out side.
(iii) Installed the top thermostat to the back cover.
(iv) Tried running heat- system shows “Heat is on” but actually heat is nor running. Tried setting everything but does not help.

Do I need to remove jumper or should keep the jumper as it is. I have two red wires coming out.

Please let me know what should I do? Is something wrong with the device?

Thanks