The U shaped pipe under my garage floor has frozen the last 2 winters in
the lengthy extreme cold spells. I have been away for 10 weeks each of
the last 2 winters. The first winter my house watcher flushed toilets
and ran water once a week. This resulted in a mess inside the house from
backing up after a few weeks. The second winter I decided to skip
having him run any water in the house to avoid a repeat situation. What
I did not realize was the furnace gave off condensation (about 3 gal per
24 hours) and goes through the waste water pipes under the garage floor
through the U shaped pipe and out towards the sewer. This amount of
water also froze over time. The 2 feet depth on each side of the U freeze
solid. I am not 100% sure but it may start in the section of pipe under
ground just outside the wall of the garage. It took 4 hours of umbels
time and 1 hour of time from a guy with a steam jenny (sp?) to thaw it
out.

I have no idea how to keep underground pipes from freezing. This is a
townhouse built on a slab. I know of 2 other homes on the street with no
one home for an extended period of time during this cold period that did
not have any issues. Any suggestions on a solution?

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