"mike" wrote in message ...

On 1/18/2014 7:33 AM, RogerN wrote:
snip

Something that happens every five years seems like a perfect place for a
manual solution.

An incandescent light bulb of appropriate wattage placed close to the
area that might freeze works fine. You have to manually control it,
every five years.

Most any old heater with a bi-metal thermostat has a calibration
adjustment.
Or, if it doesn't you can bend something.

The pipes froze up the first or second year I was here, then I used a heat
tape on the pipe that runs along the outside wall. It's hard for me to know
if the heat tape is working unless I get a frozen water pipe. The last
freeze happened on a different area of the pipe when the temperatures
dropped and it was windy. The old heating system here used a very wasteful
propane heater that's located in the utility room, that keeps pipes from
freezing but it ran through a tank of propane in less than 2 months, now I
get 2 years out of a tank of propane but have to try to keep the pipes from
freezing.

I like the idea of modifying the thermostats I could probably get a cheap
heater to do what I want.

RogerN