Hot Water System FAQ:
I have installed a Honeywell RTH230B 5-2 Day Programmable Thermostat, which allows a cycles per hour (CPH) setting to be programmed in. The furnace is hot water with a gas burner, no pump, no zones, and cast iron radiators (i.e., very old). Honeywell tech support from India had no clue–only read from the manual, which lists “hot water” and “gravity” separately, with 3 and 2 CPH respectively. This system would likely be called “hot water-gravity” right? Thanks.
Just to clarify, it is definitely a hot water system, with two pipes per radiator, and an expansion tank on the basement ceiling above the furnace.
