Hi, I successfully installed the RTH7600 on my 2 wire Weil McLain, hot water, cold start, gas fired system. I then tried to enable the battery free function by running the system common wire (C on the 28vac transformer) to the "C" terminal on the thermostat. This did not work. Should the common go to a different terminal?
RUDY

For assistance with this product, please visithttp://DIYthermostats.honeywell.comor call Honeywell Customer Care toll-free at1-800-468-1502.

For assistance with this product, please visithttp://DIYthermostats.honeywell.comor call Honeywell Customer Care toll-free at1-800-468-1502.

This information to answer this question is not available at the above web site nor will customer support give me the necessary info.