Frigid temperatures and water pipes, etc.

[Innisfree]

If a house will be unoccupied for a while during very cold weather (~ 5-15 degrees F), and the water is turned off and pipes drained and left open…

Is there any particular danger from letting the house temperature drop below 55 degrees?

The small house in question has a mini split system, with the downstairs unit functioning erratically. The unit was inspected and given maintenance six weeks or so ago, and pronounced old but functional. Now the HVAC people say that mini splits aren’t really up to dealing with the low temperatures we’re having now. I can’t guarantee it will stay at 55. I can pretty much guarantee it won’t.

I want to drain the pipes, get out, and deal with the heating system in warmer weather, because the longer I wait here, the likelier the pipes are to freeze again. Just spent two days dealing with that, had enough. Temperatures are dropping. What am I risking if I shut the place up and leave?

[Pawz4me]

I think it's safe as long as the pipes are drained. Plus there's the added benefit of not having to worry about potential leaks that could be caused by other things besides frozen pipes.

[SKL]

I think as long as it doesn't get close to freezing, it should be OK as far as pipes bursting etc.

The outside pipes may be a different story.  I might still just keep a slow drip running rather than risk having to replace the underground pipes.  (Though this might depend on what the pipes are made of.  I don't know that much, but not knowing, I'd probably run a trickle just in case.)

For pipes that are within enclosed cabinets adjoining exterior walls, I'd keep those cabinet doors open so those pipes don't get much colder than the general temperature in the house.

 

[fairfarmhand]

5 minutes ago, Innisfree said:

If a house will be unoccupied for a while during very cold weather (~ 5-15 degrees F), and the water is turned off and pipes drained and left open…

Is there any particular danger from letting the house temperature drop below 55 degrees?

The small house in question has a mini split system, with the downstairs unit functioning erratically. The unit was inspected and given maintenance six weeks or so ago, and pronounced old but functional. Now the HVAC people say that mini splits aren’t really up to dealing with the low temperatures we’re having now. I can’t guarantee it will stay at 55. I can pretty much guarantee it won’t.

I want to drain the pipes, get out, and deal with the heating system in warmer weather, because the longer I wait here, the likelier the pipes are to freeze again. Just spent two days dealing with that, had enough. Temperatures are dropping. What am I risking if I shut the place up and leave?

MAybe not for pipes, but beware if you have drywall. Our church has thousands of dollars of drywall damage because the temps got so low indoors that it began cracking as things warmed up. But I guess if the heating unit isn't working, then it isn't working and you gotta just do what you must.

[Innisfree]

2 minutes ago, fairfarmhand said:

MAybe not for pipes, but beware if you have drywall. Our church has thousands of dollars of drywall damage because the temps got so low indoors that it began cracking as things warmed up. But I guess if the heating unit isn't working, then it isn't working and you gotta just do what you must.

Mostly plaster, some drywall. Thanks, that’s the sort of thing I knew I didn’t know.

[prairiewindmomma]

Most materials become more brittle when exposed to cold temps—even empty plastic plumbing pipes can crack in cold temps. It all depends on what temperatures are rated for.

In many climates a lack of heat also means a lack of humidity control. Depending on how long you are gone = mold.

One question to ask is if your plumbing lines are all blown out—what happens to the sewer line and sump pump. Family just had their sump pump freeze over and once things start to thaw, she will overflow if it’s not back in place by then, and that drains from the house out to the sewer.

 

 

[Miss Tick]

My in-laws' house got cold one winter while they were away and all their dishes crackled. So give a bit of thought to what you would leave behind, I guess.

[MEmama]

For the future, modern heat pumps work fine in those temperatures. They've gotten significantly better in recent years in cold weather efficiency. Heat pumps are extremely popular here, though it's always advised (and some insurers insist) that there is a secondary heat source as well. That's true regardless in this climate though.

I know this doesn't help your situation right now, but if you are interesting in installing new heat pumps in the future, many states offer incredible rebates, often through their efficiency programs. It's definitely worth researching if you're ever in the market.

Good luck; I hope you can find warmth!

[Innisfree]

7 minutes ago, MEmama said:

For the future, modern heat pumps work fine in those temperatures. They've gotten significantly better in recent years in cold weather efficiency. Heat pumps are extremely popular here, though it's always advised (and some insurers insist) that there is a secondary heat source as well. That's true regardless in this climate though.

I know this doesn't help your situation right now, but if you are interesting in installing new heat pumps in the future, many states offer incredible rebates, often through their efficiency programs. It's definitely worth researching if you're ever in the market.

Good luck; I hope you can find warmth!

Modern heat pump is probably on the horizon. Something modern assuredly is…

[sweet2ndchance]

We had a drained PVC pipe shatter under the house earlier this week from low teens to single digit night time temperatures. The only reason it didn't flood under the house was because the line was drained (it's for outdoor use only so we drain it and shut it off in the winter) but it also shattered under the pressure tank in the wellhouse. So the wellhouse flooded which isn't fun but at least it is away from the main house. Since we only use the well for outdoor water, it wasn't too bad. Our main city water line froze as well but it is made of pex and resisted breakage just fine. We got the lines insulated and it has been fine since. Fingers crossed this next round of cold the beginning of next week doesn't do any more damage. We keep the house in the sixties to upper fifties at night. According to the plumber, those indoor temps had no bearing on the lines that we had freeze. Ours were all outdoor lines that should have been insulated but were not when they were installed last summer.

[Innisfree]

1 hour ago, SKL said:

I think as long as it doesn't get close to freezing, it should be OK as far as pipes bursting etc.

If we leave, the downstairs is guaranteed to get close to freezing. It was at 32 degrees F a couple of days ago. I’ve spent the time since then laboriously, painstakingly raising temperatures, with no evidence that pipes have burst. I can’t maintain temperature above freezing without the use of space heaters, though, so obviously can’t do that if I leave. Apparently the mini split can limp along with help from the space heater.

It looks like I’m staying longer. Can’t locate the outside water meter turnoff. The city will turn it off for me early next week, but I have to keep things warm until then.

Thanks for everyone’s ideas. 

[Innisfree]

5 minutes ago, sweet2ndchance said:

We had a drained PVC pipe shatter under the house earlier this week from low teens to single digit night time temperatures. The only reason it didn't flood under the house was because the line was drained (it's for outdoor use only so we drain it and shut it off in the winter) but it also shattered under the pressure tank in the wellhouse. So the wellhouse flooded which isn't fun but at least it is away from the main house. Since we only use the well for outdoor water, it wasn't too bad. Our main city water line froze as well but it is made of pex and resisted breakage just fine. We got the lines insulated and it has been fine since. Fingers crossed this next round of cold the beginning of next week doesn't do any more damage. We keep the house in the sixties to upper fifties at night. According to the plumber, those indoor temps had no bearing on the lines that we had freeze. Ours were all outdoor lines that should have been insulated but were not when they were installed last summer.

I’m sorry you had to deal with that. Winters are rough, especially when things aren’t standard modern designs.

[Ginevra]

I was going to suggest a space heater, but we use the oil radiant type of space heater. They are fine to leave on without being attended. Let me go find one of what I’m talking about  and drop in a link. 
 

Dh is very mechanical and he advises all people to never, ever leave the house completely unheated in below-freezing weather. It’s harmful to more things than just pipes. It also can destroy hardwood floors, trim board, drywall, cabinetry, can make doors buckle so they don’t close anymore…lots of things are bad about severe contraction due to cold. 

Edited January 19 by Ginevra

[Innisfree]

56 minutes ago, Ginevra said:

They are fine to leave on without being attended. Let me go find one of what I’m talking about  and drop in a link. 

You wouldn’t leave town for a couple of weeks leaving one on, though, would you? That’s the kind of absence for which we need to prepare.

I suspect I’m here until we can get new, reliable heating installed. This is an old house, in a complicated family situation. The systems need updating. I appreciate hearing advice from people like your dh; this isn’t my area of expertise, obviously.

[Ginevra]

52 minutes ago, Innisfree said:

You wouldn’t leave town for a couple of weeks leaving one on, though, would you? That’s the kind of absence for which we need to prepare.

I suspect I’m here until we can get new, reliable heating installed. This is an old house, in a complicated family situation. The systems need updating. I appreciate hearing advice from people like your dh; this isn’t my area of expertise, obviously.

Yes, I would. I do, in fact. I have one in the garage to keep my cat cozy. It is on all winter, home or not. Don’t get me wrong; I’m not telling you you *should*. Just that I have used them extensively and never had an issue. If it was a toss-up between leaving that kind of heater in a vacant house vs. leaving a vacant house with no heat in sub-freezing temps, I would absolutely leave the oil radiant heater on rather than risk letting the house freeze up. 

[SKL]

There's probably a way to put a space heater in the middle of an empty room with something safe under it (nothing to catch on fire should something go wrong).

I'm no expert, but there probably are experts somewhere who could provide a suggestion.  Maybe a construction person who often needs a space heater in order to perform work in the winter.

[Beth S]

We have an uninsulated (vintage) cabin in northern Wisconsin that we only use in summer.
We pour RV antifreeze in the drains of each sink/shower/toilet AFTER draining the water from them.
A very inexpensive solution--it's a pink fluid, & we bought it at Walmart.

Another option is to have a neighbor come over & check on the house periodically.

We put a space heater in our crawl space, on nights like this.
(We have a small leak right now in an outdoor faucet, so my dh has been turning off the main water valve each night as a precaution.)

Two of our neighbors have experienced catastrophic loss from upstairs frozen pipes and a water heater failure when the house was empty, so we don't mess around!
Great question to ask the Hive!

Edited January 20 by Beth S

[Innisfree]

I really appreciate all the ideas.

At this point the pipes have thawed with disaster seemingly (🤞) averted. We can shower, the house is toasty, and the space heaters are helping the mini split. I think we’re just going to hang out here and keep things stable until the worst of the present low temperatures end on Monday or Tuesday. We’ll be replacing the mini split with an updated system ASAP. Thanks for helping me think through options yesterday, when my mental coping skills were at particularly low ebb.

[Carol in Cal.]

Even if you drain the pipes, usually there is water in the traps—the u shaped pipe areas in toilets and under sinks and probably showers.  So after draining, pour about a cup of R antifreeze into each drain and the toilet tank and the toilet bowl.  We do this just about every time we leave from November until the snow is gone (May or June) if we expect to be gone more than a few days.  That will help.  It is also a good idea to leave the cabinet doors open if there are traps in them.  That way when the heater IS on, the warm air has a chance to get in there.

We don’t siphon all the water out of traps because that allows smelly or even toxic gases from the septic tank to drift up into the house.  That’s considered a serious health hazard and I think maybe a flammable hazard as well.

Check your property insurance for heating requirements.  Ours at our cabin says that we must make every effort to keep the house at or above 50 degrees or else the insurance is invalidated.  So we leave our heater at 50.  There is one heating vent in the basement and we tie the door to the room with the main main water line open so that the water line is exposed to the heater from the next room in the basement.  Of course, if the power goes out the furnace is also off, so that’s not a complete fail safe.

The line to there is underground, and we are guardedly optimistic about that.

Other issues:

—When the house starts to warm up again, heavy pieces of upholstered furniture stay cooler longer than the air around them or lighter wooden or plastic furniture.  So condensation can form on them and drip onto the floor underneath.  If that happens you can have damage to that floor, of course, but also if you keep an eye out for this and wipe under that kind of furniture a few times in each warm up period it can supposedly be preventative.  We have woven wicker furniture in our living room instead of upholstered.  It is not as comfortable but it doesn’t do this.  We really want regular upholstered furniture there so we are going to get some, but we are looking for the kind that is raised off the floor without a skirt so there is air circulation under it.  

Last year we had very heavy snow, and there was a cabin up higher than ours that got more than we did that actually had the roof collapse from the weight of it.  It is quite dangerous to shovel snow off a cabin roof on a cabin on a hill so it’s hard to know what he could have done to prevent this but it was a genuine catastrophe.  Fortunately there was no one in it at the time.  A couple of years before that there was a weird phenomenon wherein a lot of wet, heavy snow fell quickly without any wind.  It built up on the trees, and the weight of it snapped the tops off of a lot of them, especially the younger ones with trunks on the narrow side.  Thinning little trees in an evergreen environment is maintenance that we do regularly.  

Also, extreme temperature variations can make wooden floors hump up and completely ruin them.  That’s more a hot weather expansion problem but it also has to do with their attachments weakening in extreme cold, allowing them to let go when heated.

Edited January 20 by Carol in Cal.

[prairiewindmomma]

One other tidbit for people to consider in the future is what your insurance policy says re: required occupation of the home. Our home owner's policy insurance in a previous state would not cover any losses if the property had been unoccupied for longer than 30 days. Vacant/unoccupied property insurance is a separate rider--either an additional endorsement onto your current homeowner's policy or it can be a separate policy. Vacant = empty, but unoccupied means utilities are on and belongings remain in the home.