CT101 Heats fine but won't Cool, instead Heats in Cool mode

Have just moved and took my CT101 with me. Have hooked up to Heat Pump and when set to Cool it puts out Heat instead. When in Heat mode it also puts out Heat as it should. Have triple checked my wiring and switches and it’s connected per the manual. Works perfectly with the old thermostat. I see that someone had this issue before but any resolution wasn’t posted.

Have the below wires connected, exact one for one match with old thermostat…
G, C, RH, Y, W2, O


Maybe if you took a picture of it hooked up someone might see something you missed

Sure thing here it is.

You might try a factory reset and then make sure you select the correct HVAC setting on one of the set-up screens. There should be a page in the manual that explains which one you’ll need given your system. I’m not sure if the wrong setting would cause your problem, but it’s an easy check fix it that’s it.

Dad and I went 'round and 'round initially setting up his CT101 with heat pumps, and a factory reset put everything straight, and it’s not been an issue since.

Hope that helps.

That’s a CT101? From what I remember the connections were on top.

My guess is that it’s got something to do with not having a connection to Rc

If I remember right on my heat pump they were jumpered(Rc Rh). Not 100% sure on that though, it’s been quite some time ago and I no longer have it so I can’t look. These power the transformers to the AC and heat unit.

It looks like he used the wall plate for wiring. You connect wires to the wall plate, then the thermostat just pops on the wall using the pins on the plate and the connector on the back of the thermostat. Works great, and it hides the holes of a previous installation.

I think you need to move the white wire from the W2 terminal to the W terminal based upon your picture.

Can you give that a try please, and make sure you have your setting correctly configured for heat pump?

I don’t have a CT101, but most heat pump thermostats usually have the white wire on W. That’s how my Pearl is set up, and it’s a fairly basic thermo.

This, I don’t know a whole lot about that kind of wiring, but I do know that the Rc wire is part of something to do with AC. Since nothing is connected to the Rc (C for cooling) terminal, it’s probably not getting a signal/power/something that the AC needs to kick on. All it knows is the Rh (H for Heat) is getting whatever it is instead, so it turns on the heat. I found a good article a few months ago when I installed a new thermostat, but I can’t find the link now…

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@dpace23236, Sully (@jsulliweb) makes a great point. There’s no jumper between RC and RH that we can see in your picture. Is there something on the back that we can’t see? Did the old thermostat have these 2 jumpered? I’m betting they were.

Problem solved, just required a Reset of the thermostat. it was wired correctly. Thanks for everyone’s input, great community!

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