Need advice/help on old Temstar thermostat

Problems related to residential installations.

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Need advice/help on old Temstar thermostat

Post by renoman22 » Mon Dec 05, 2016 4:22 pm

Hi guys. I am a home owner and novice when it comes to A/C or heating. I hope it's ok to ask for help here. I recently bought a house and the heat pump unit was not cooling but the heat was working (on aux/emergency heat). The outside unit was not working at all. I replaced the contactors and capacitor myself. Still dead. That was as much as I could do myself so I called some a/c guys to come out. They checked it over and concluded the compressor was shot. The unit was old (a 1994 model) and they suggested just getting a new unit altogether. BUT I had just gotten screwed by a plumber that over charged me by about $2,000 so I didn't have enough money to buy a new unit. Luckily the guy said he had a used unit (2008 Goodman) that he had taken out of a home that ran fine and would install it for $500 and give me 6 months warranty. They came and installed it and it seems to be working fine.

BUT the thermostat inside is an old Tempstar (mercury style) thermostat. I wanted to install a Honeywell Focus Pro 5000 thermostat. The problem is when I remove the cover to see the wiring, the wiring doesn't match what is needed for the new thermostat. It does have 8 wires (blue, white, pink, gray, red, orange, black, green). I'll try to attach a photo below but I am not sure if it will show. The orange wire is going to O, the yellow to Y, the white to W but has a jumper going to the X, red to R, blue to B, and green to G. The pink, gray, and black are not being used. So I guess my question do I wire this thing?

I am not sure the old thermostat was even hooked up correctly to begin with. The Goodman unit is energized in cooling, so the B terminal shouldn't have a wire going to it, correct? Also the yellow light for Aux heat and the red light for the emergency heat come on at the same time on initial heat up. Is that normal? Is that because the white wire is going to W is jumpered to X??

Any advice would be greatly appreciated!

Here's a pic of the old - *.*/albums/e173/renom ... 0&*

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- Need advice/help on old Temstar thermostat

Post by Freon » Wed Dec 07, 2016 1:10 pm

Go to the air handler and check the terminal designation where the thermostat wires connect. We need to know what terminal the X wire at the thermostat connects to. If the old unit was dead the previous owner may have only used the Aux.Emergency heat which are the electric heat strips in the air handler. That could be why the W and X are jumped at the thermostat. But until we know each terminal connection at the air handler we're guessing.

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