I purchased a Honeywell RTH6500 Wifi Thermostat, which requires a C wire. My old thermostat showed a connected blue C wire. However, it was battery-powered. If I removed the battery, the thermostat screen would go dark. After I connected the RTH6500, I measured with a multimeter, which showed 0V on the C wire. All the other wires showed positive voltage. I went up to the air handler and saw there was a unconnected blue wire. Would I be ok stripping the blue wire and connecting it to the other two in the wire nut?
In the picture that shows the wires near the air handler, I'm guessing the three sets of wires are going to the (1) air handler, (2) heat pump, and (3) thermostat. You can see the green wire is also unconnected on a different set. The green wire on the thermostat is connected to G, which I think is the fan. I think that set of wires is probably going to the heat pump, since it doesn't have a fan?
I appreciate any help. Thank you.
I just want to double I'm doing the right thing before I open up the air handler. It looks like the wires are coming out of the panel on the right, so I'm going to open that one up. Also, I've turned the breakers for the both air handlers and both heat pumps off. That should cover it, right?
I opened up my air handler, and I'm seeing the blue wire connected to B terminal on the air handler. I found a wiring guide for Trane, but it doesn't exactly say B is common. The Honeywell wiring guide shows that B can go into the C terminal. I'm not sure what to make of this.