Hello all experts: I recenty bought a new Honeywell thermostat to replace my old GE thermostat. How do I connect the wires? My heating system is using heatpump with multistage. Thanks a bunch! Ben

The blue will go to "C", the red will go to "RC with jumper to "RH", the green will go to "G", the orange will go to "O/B", the white will go to "AUX.", the yellow will go to "Y", the brown will be taped off (it goes to a thermister in the outside unit) not used, the black will go to "E". Program thermostat for "O". Good luck. Mike

I eventually installed the thermostat as instructed. Tried it by raising the temp 2 degrees to 77 degrees, heat pump runs, heat air blows, but screen shows Aux heat on. This is not what I expected, I expect to blow heat from the heatpump.
The screen show the inside temp still at 75 degrees without change, air blow stops but the heatpump keeps running.
Next, I am going to try the cooling system.

I raised the temp to 80, the heat air blows and raised the inside temp to 76 with Aux Heat On. I stopped the heating system.
Now I am trying the cooling system, I set the temp to 66 degrees, heatpump is on but there is no cool air blowing. I have been waiting for 10 minutes now.
Please advise!

You may have to tell your thermostat that you have a heat pump and that it uses the "O' terminal for the reversing valve. Check your installation manual for the advanced setup.

You may have to tell your thermostat that you have a heat pump and that it uses the "O' terminal for the reversing valve. Check your installation manual for the advanced setup.

I did setup the function 0170 to number 7 as Multi-stage heat pump: Heat pump with backup or auxiliary heating.
I also did setup the function 0190 to number 0 as Cooking changeover valve: Use this setting if you connected a wire labeled "O" to the O/B terminal.
Is it normal that the heat is using Aux Heat at the whole time?

Should I jump from Aux to E?

It may be possible that the aux. heat is running when you raise the temperature setting on the thermostat in the heating mode because you have exceeded the temperature differential between the first stage and second stage heating. You don't need a jumper.

My cooling system is not blowing cold air, is it suppose to blow like heating system? The heat pump runs on both systems.

It is suppose to run in heat and cool mode, the reversing valve will have to energise to get cooling, if you have a volt meter you can check for 24 volts at the reversing valve or between the 'O" terminal and the "C" or common terminal, if no 24 volts here then it will be in heat constantly, make sure thermostat is in cooling mode and calling for cool, if you don't have a meter then with unit running put a jumper between the "O" and the "R" terminals in the outside unit, you should hear the valve change over, if it does not change over you may have a faulty solenoid coil on the reversing valve.

I have a volt meter. So I will put the red and black needles on both "O" and "C" without turning off the power, am I right?
Or without volt meter, I will take off the outer panel on the heat pump then put a jumper between the "O" and "R" while the power is on?

With the power on and the thermostat calling for cool, you should check the terminals "C" and "O" at the outdoor unit, or jumper "R" and "O" with the unit calling for cool.This is all low voltage controls and you should read 24volts.

Thanks and I let you know the result.

I don't see the terminals of "C" and "O" on the heatpump. I also found that the pipes going out from the unit to the wall are icy after I turned the cooling system on. The ice was melt after I turned the thermostat off.
Any further picture you want me to take?

It appears that your indoor fan is not running, check at the air handler to insure the fan is running and if it is check the filter.

I tried to search the posts with pictures to check the air handler but I did not find.
Please advise how to check the air handler.

Do you give up helping me?

Will give you all the help you need. The ice on the lines in one of your pictures indicates that the indoor fan was not running or there was something restricking the air flow.
With the panel off, turn on the fan at the thermostat and see if the fan runs. If it does not run then take the red and green wires loose at the thermostat and twist them together, now see if the fan is running.
The last pictures are of the air handler.

Finally, I got a chance to test it. I set the thermostat to fan on, there is no blowing while the heatpump runs. I then twisted the red and green wires together then turned the power on, the heatpump runs, the air handler has electric buzzing noise but the fan doesn't run.
I took some pictures, the upper one is the relay in the air handler, the middle one is the recent thermostat and the lower one is the filter.
I will test the volts if you could lead me. The temp in Seattle is getting cold, please help!