Hi

I have an electric hot water boiler I believe it is a HYDRA model. It has three zones and I recently replaced the thermostats to Honeywell RTH230B, 5-2 Day programmable. One of the zones, in the basement, is NOT working right. The thermostat is set at 70 F and 60 F. The problem is that the tempature never goes below 70F, in fact, tonight for instance, the temp. was at 76 F and the water starting circulating and heating up the area more. The temp would go up to 79 F before switching off. I hope I have explained this well enough to get some sort of advice because I am at wits end. I don't know if it is the thermostat and why would it call for heat when it already is above the set temp?

Thanks.

First thing. Disconnect the thermostat in the trouble area and see if that cures the problem. If it does you have a thermostat problem. If not post back.