Where I live in Ontario it's been really cold lately but our house out at
the lake is 99% shut down when we leave for the year. Drain the tank and
shut off at the panel. If you like tape the breaker with a note that says
"Fill Tank with water". The cold in the house will be good for it and kill
anything that is trying to call it come. My vote is to shut it down and stop
worrying. The only thing we leave on is the electrical to the outside
spotlights and security system.




"Dugie" wrote in message
...
Hi,

We're looking after a house which has been vacant for about 6 months, and
will be vacant for at least a few more. We check it every 2nd or 3rd day.

Nova Scotia, Canada, climate in winter is cold, often well below freezing,
sometimes down to -20C or lower (about -6F).
5 year old hot air oil furnace set at about 68F, serviced this summer.

Two months ago, we turned off the main water supply valve, left all taps
open and water drained, including outside taps, toilet tank empty. I forgot,
so power flowed to the electric hot water tank until last week, and the tank
was full.

Question: about draining the hot water tank, which now has the power supply
breaker off:

Drain water, or leave full?

If drained, will the tank be more likely to rust from inside?
If full, and the furnace fails, I suppose the tank may freeze and crack.
If partly filled, what happens?
Currently it's almost completely drained.

Tank is in heated basement, inlet & outlet pipes go upward. The basement
laundry tub valves are open.

Thanks!
Dugie