Attachment of a "C" wire from a WiFI thermostat

teablender

I have an Energy Kinetics System 2000 Boiler Model EK1. I am replacing an old two wire thermostat with a new programmable WiFi capable one (Honeywell RTH6500) and need to know where to connect the "C" wire to the 24 VAC common on the Energy Manager board. My system supports two heat zones and a domestic hot water zone.

Thanks.

HVACNUT

Your common is "A2" on the Energy Manager.
Leave the other 2 wires alone.

Alan (California Radiant) Forbes

See attached page 15, terminals A1 and A2 are the transformer leads. You would have to use a meter to tell which one is the "C" terminal.

https://energykinetics.com/wp-content/documents/system2000/installer-manual-ek1-ek2-oil.pdf

That said, I would not recommend running your thermostat off the boiler transformer. If something goes wrong, you can easily fry a $500 circuit board.

I would power your stat with a pump relay like a Taco SR501 where they give you a "C" wire terminal.

https://s3.amazonaws.com/s3.supplyhouse.com/manuals/1351090952835/85160_PROD_FILE.pdf

teablender

Thanks for your advice. I will investigate the URLs. I appreciate all the comments/recommendations.