How to deal with freezing pipes

[TimJ2021]

I have a house that I want to winterize. I will be thousands of miles away from it, so if the pipes freeze I will not be able to do much about it. What is the best strategy to minimize the risk:

A) Turn off the water main, knowing that I may not be able to drain every line. By turning off the supply to the whole house, if a pipe freezes, I can avoid complete catastrophe.

or

B) Leave the water main on with the thinking that water has a lower freezing temperature when under pressure but risk a major leak from freeze or other unrelated reasons

or

C) Leave the water main on for reason in (B) but leave a small trickle of water flowing because there is now an outlet for expansion

or

D) Something Else

Thanks
Tim

 

[Reach4]

I would say probably A, and open other valves. Alternatively C I guess.

The main valve often has a place to open to let it drain.

Then pile insulation around the pipe before the valve and the valve itself.

Not B, because the change in melting point with pressure is very small. https://www.engineeringtoolbox.com/...re-point-pressure-d_2005.html?vA=200&units=B#

 

[Sponsor]

 

[Breplum]

If the house was not originally designed for winterization, then hire a plumber to provide drain ports where necessary and then blow out with compressed air at all points.
vac out all p-traps

 

[Fitter30]

If you have city water valve it off hopefully meters at the street Still turn it off heat trace to the shut off open all the valves including the water heater drain. Toilets, sinks, and drain traps rv anti freeze in all of them. Clothes washer disconnect the hoses. Drain hose take a shop vac that can suck water lower hose could gallon or more in it. Leave the hose down. Leave the dish washer door cracked open

 

[TimJ2021]

Thanks, I will go with (A)

 

[Eman85]

Keep in mind P traps and commodes will freeze along with washing machine pump and water heater.

 

[JohnCT]

Keep in mind P traps and commodes will freeze along with washing machine pump and water heater.

Question, are the traps less likely to split because they are open on both sides? Pumps trap water so we know the answer to that.

John

 

[Clutchcargo]

Is leaving the heat on 50°F an option?