Ask Me Help Desk - Installing a digital non programmable 5 wire thermostat

I have a digital non programmable thermostat. I have 5 wires (yellow, red, white, blue and dark brown) could you tell me where do they I took the old one and didn't pay attention where the blue and dark brown go.)
Thank you very much.
I hope you can answer this today since it is very cold this evening to sleep without heater.

Is this thermostat for a Air conditioning system with a gas furnace or is it for a heat pump with ememgency heat ( Gas or Electric)

Bad time and place to hurry when starting a job. The first part of the instructions on that new tstat will tell you to label the wires when removing the old unit. You DID read the instructions didn't you? Err in haste, repent at leisure.

This is scary giving advise when I have no idea what type of system it is. If it gets hooked up wrong on the wrong system, you could have a real bill on your hands. I want no part in that. What brand and model is the new tstat? You are certain that it IS compatible with the heating /cooling system that you have? If you got a heat pump only thermostat it may not work with a combustion/cooling coil system.

Is your system a
1) heat pump?
2) gas or oil burner with cooling coil?
3) two separate systems (1 heat, 1 cool) run by the same thermostat?

Was the old thermostat mechanical or electronic? If electronic, did it have batteries? Were there any indicator lights on the old tstat? What were the terminals labeled on the old stat? R, W, Y, G, C or did it have Rh, Rc, O, B, E, F, L,. in place of any of the first 5 I listed? How old is the heat/cool system? (This might indicate what labels it had). Is that "dark brown" or "blue" wire actually green?

Unless you can give more information, or can read the schematic(s) on the systems and figure it out from there, call a professional.

EPM

Quote:

Originally Posted by EPMiller

Bad time and place to hurry when starting a job. The first part of the instructions on that new tstat will tell you to label the wires when removing the old unit. You DID read the instructions didn't you?? Err in haste, repent at leisure.

This is scary giving advise when I have no idea what type of system it is. If it gets hooked up wrong on the wrong system, you could have a real bill on your hands. I want no part in that. What brand and model is the new tstat? You are certain that it IS compatible with the heating /cooling system that you have?! If you got a heat pump only thermostat it may not work with a combustion/cooling coil system.

Is your system a
1) heat pump?
2) gas or oil burner with cooling coil?
3) two separate systems (1 heat, 1 cool) run by the same thermostat?

Was the old thermostat mechanical or electronic? If electronic, did it have batteries? Were there any indicator lights on the old tstat? What were the terminals labeled on the old stat? R, W, Y, G, C or did it have Rh, Rc, O, B, E, F, L, ..., in place of any of the first 5 I listed? How old is the heat/cool system? (This might indicate what labels it had). Is that "dark brown" or "blue" wire actually green?

Unless you can give more information, or can read the schematic(s) on the systems and figure it out from there, call a professional.

EPM

I don't know if is heat pump.
It was a mechanical. There were two separated in one thermostat. The old was a mercury/knob made by honeywell.The heater is electric. The ac is a 2 ton 10SEER 230v 1PH condensing unit 70 psi sunction pressure and a temp drop 18.1 of. The wire it is blue and the other is dark brown. The new is a honeywell RTH110B

Sorry for the long absence. Christmas, family get-togethers and all that.

Quote:

Originally Posted by neth68

I don't know if is heat pump.
It was a mechanical. There were two separated in one thermostat.

Two what separated in one thermostat? Two thermostat units? Two wires?

Quote:

The old was a mercury/knob made by honeywell.

You mean one of the Honeywell "the Round" units. Usually gold. Get that old unit and tell me the letters by the screws that the wires were hooked up to. If you threw it in the trash, shame on you. That has too much mercury in it to do that.

Quote:

The heater is electric.

Electric furnace or electric backup heat, aka emergency heat?

Quote:

The ac is a 2 ton 10SEER 230v 1PH condensing unit <snip>. The wire it is blue and the other is dark brown. The new is a honeywell RTH110B

It still could be a heat pump, and not compatible with that Honeywell RTH110B that you have. I must know more fully what TYPE of AC system you have before we can go any farther here, but it sounds more and more like you should call a professional in. It will not take them very long to do it.