[sleepingsaguaro]

We have an old GE thermostat, model # 3AHT10B1A2. There are 2 white wires on the left and one red wire on the right. The directions on the new thermostat show 4 different colored wires. We can't tell what's what. Does anyone have a user's manual they can share? We contacted GE and Trane with no luck.

Thanks

[EPMiller]

What are the terminals in the old tstat labeled? W? R? C? Y? What are the labels on the terminals on the new tstat? What color wires do the instructions show?

[sleepingsaguaro]

G, y, w, r

[EPMiller]

G, y, w, r

Old stat? New stat? If you don't have enough time to give good details and explanation, I'm not going to take the time to try and guess an answer.

[emeryCT87K]

I'm trying to replace the old 2 wire mercury thermostat with a Honeywell CT87K. The new has a olace for 3 wires, Red, white, and yellow and 2 tiny switches. What position should the switches be in and where do I attach the wires. It wll be use to control a hot air oil furnace. Thanks, Gerald

[EPMiller]

I'm trying to replace the old 2 wire mercury thermostat with a Honeywell CT87K. The new has a olace for 3 wires, Red, white, and yellow and 2 tiny switches. What position should the switches be in and where do I attach the wires. It wll be use to control a hot air oil furnace. Thanks, Gerald

What wires went to which terminal on the old tstat? Hook them to that terminal on the new tstat. R and W most likely. I don't know what the switches are on a CT87K. I didn't think that one had switches. What are they labeled? Fan? Heat/Cool? I am not familiar with that exact model. I have CT87A, T87N, etc, but not that exact model so I can't be positive, but I would hazard that the one should be set to Heat and if the other is Fan, it won't matter because you don't have a fan control wire.

EPM

[hvac1000]

Here is the manual for your CT87K thermostat. Just follow the directions.

http://customer.honeywell.com/techli...69-1959EFS.pdf