I asked this question several weeks ago and didn't get any answers, so I'm going to try again, as I can't stand having the thermostat set so high. We are going into another cold snap, so here goes.

Our heater has not been working efficiently lately, and when we had it checked out, the HVAC guy mentioned we might be keeping our furnace set too low to avoid frozen pipes. He wasn't sure what we should keep it set at, though, as he's never lived in a cold climate before. My question is, how low can a furnace be set without worrying about freezing pipes? Running water is not an option as we're on a very strict water budget and it's extremely expensive to go over budget. Our house is pretty well insulated, although I have no idea to what R value. We do have a finished basement with a bathroom that seems to get down into the upper 40s or low 50s when the space heater isn't being run. There is a bathroom in the basement, as well as the water heater, but they are both separated from where the space heater is run.

Thanks for your help!

I keep losing this post. You can't change the temp water freezes which is 32F.

Options:
1. Heat tape designed for this purpose: Pipe Trace Freeze Protection Heating Cable (http://www.heatersplus.com/pipes.htm?gclid=CM6gjtqB3Z8CFQOfnAodGUUKGw)

2. Use a hot water recirculating system such as this with some tricky controls. Advanced Conservation Technologies: D'MAND Hot Water Systems (http://www.gothotwater.com/)
Uses last fixture in the hot water supply. Tie it to space or pipe temp with a one shot timer. (not easy)

3. Keep space above 40F. Some stats won't go that low.