1

I need help connecting a new 'C' wire for a Honeywell RTH6500WF thermostat.

Current Wiring Diagram As you can see the heating is an old boilder with a simple pump to circulate the hot water to the baseboard radiators.

The A/C has 3 connectors to it. A/C Schematic

This is the circuit board in the Blower AC connectors

This is the current thermostat current thermostat

I know I need to run a new wire for the additional wire but WHERE do I terminate the 'C' wire to on the thermostat? on the C terminal inside the A/C blower?

That wire runs to the compressor outside and then to the Y terminal of my current thermostat. Do I just need a new transformer? and how would I create the circuit on that.

Any help would be greatly appreciated.

Thank you.

0

You want the C terminal in the air handler, yes

The terminal you're looking for is indeed the air handler's C terminal -- it's on the fan-delay board (in the back left, from the viewpoint of the picture you've posted). You'll want to tap the connection it's making to the blue wire using a "piggyback" tab terminal or by cutting and splicing into the blue wire connected to it with a wirenut.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.