We are installing a special heating coil into a clients plenum that circulates solar heated hot water and need to control a circulation pump and the furnace fan. Looking for the simplest control to do to do this.
Logic of the needed control is that when the temperature in the hot water storage tank is more than a settable amount, let say X (about 100deg), and we get a heat call need to turn on the 110v a/c circulation pump and the furnace fan, however, if the temperature in the tank is not X then I need to fall back to normal furnace operation.
I found a 24Volt control (Johnson Control A419) that can sense the temperature in the tank and turn on a power-strip that would be connected to the 110V a/c pump. This would give the control that is needed however it would not give me the fall-back logic when the temperature is not X to fall-back to normal furnace operation.
Suggestions for a thermostat or control would be appreciated