Welcome! Here are the website rules, as well as some tips for using this forum.
Circulator Control for Unit Heater
Hello. I am going to put a hot water unit heater in a garage. The garage is not normally heated (will use heat only intermittently). So the unit heater and piping will be exposed to freezing temps. I don't want to use glycol in the system. I've heard there is a control system that uses a sensor to sensor when the water in the system reaches a set point (some temp close to freezing) and then turns on just the circulator pump and not the fan. That way just the water in the system is kept warm enough not to freeze. The garage is foam insulated so it doesn't get below freezing that much, but I don't want to heat it full time. Is there such a device ? Thanks.