I need help connecting a new 'C' wire for a Honeywell RTH6500WF thermostat.
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.
This is the circuit board in the Blower
This is the 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.
Best Answer
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.