Where do you live? Also is your garage attached to a building that is heated or is your garage insulated? I know our garage is insulated and it also has the furnace and water heater in it. Because of those, the garage stays above freezing even when it's way below freezing. I guess a thermostat could do keep it at just above freezing. **://-.prothermostats.com/-* **-* has thermostats and might have what you are looking for.