The only time I ever used it was at a friend's condo. I installed it fairly low in the system and it thawed the line after about an hour even though the block was probably about 10-20 feet away buried in the structure. This pipe was close to a north wall that was probably inadequately insulated. They froze up once or twice a year before I put in the tape unless someone rememberred to open the tap on bad days.
Even though it's a nuisance, you may want to consider draining the pipes and water-heater if you are going to be away for long periods during the winter. Otherwise, I'd be cautious and set an hour every 4-12 hours.
Good luck!
|