[Roso]

The pipes to our kitchen sink froze a coupke of days ago. As in past winters, we put a small space heater under the sink to thaw them out. We did the same thing this time and it worked except that we're only getting cold water. When we turn it over to hot it's just trickling out. This has never happened before.We have turned the faucet to hot and all the way open, and checked our water meter and there's no activity, so we're thinking it's not a burst pipe. We figured if a pipe had burst, the needle on the meter would be spinning. No other faucets in the house are affected. Any ideas?

[creahands]

Your hot water is still frozen. Leave it on with the trickle and heater under sink. The trickle over time will bring hot water to the ice and melt it.

You should try to fix problem when weather gets warmer. One of these times freeze will crack a pipe and you will have a big mess.

Good luck

Chuck

[Roso]

Thanks Chuck. Thing is, I don't understand why the cold water pipe unfroze sooner, and it's taking so long for the hot water to unfreeze. This happened before and they both unfroze at the same time.

[creahands]

Don't know the scientific reason, but hot water freezes first and takes longer to defrost. It has something to do with the molecular construction.

Chuck

[Fr_Chuck]

Yes hot water will freeze differently, before it always took longer, you never noticed it before most likely. Also part of the ice may have moved and is still frozen further along and has blacked a valve perhaps

[speedball1]

I don't understand why the cold water pipe unfroze sooner,

Because the cold water has more oxygen bubbles in it while the hot water sets in the tank and dissipates making it heavier then cold water, Does that answer your question? Tom

[Roso]

The hot is coming out now in a small but steady stream but still not like it should be. It's never taken this long before. If we did have a pipe burst would we still be getting any water out of the faucet? We have a one-story home with a crawl space (where all the pipes are)?

[creahands]

Shut all faucets in house and check water meter. If not moving you do not have a leak or busted pipe. May still have some ice in line.

Chuck

[smearcase]

If that is hot water coming out of the suspicious pipe, the chance of ice blocking anything in that line is just about zero. I had a 1/2 inch copper line freeze one time (hot water line).
It created a split in the copper about one half inch long along the length of the pipe, and maybe 1/32nd of an inch (if that) wide. I had too much water coming out of a light fixture (looked like Laurel and Hardy had wired and plumbed the house) to see if any was coming out of the faucet but I am quite sure that there would have been water coming from the faucet. The leak was in the attic and it looked like a rain forest up there.
Have you taken a look in the crawl space? If it is busted there you should see it and hear it as soon as you start in. There may be other explanations which I'll leave to the plumbing experts (which I ain't) but if you haven't looked in the crawl space yet, and that is hot water coming out of the faucet, you should rule out a busted pipe at the soonest opportunity.

[ballengerb1]

The scientific principle is called the Mpemba effect, under certain conditions hot water can freezs quicker than cold. Also you hot and cold pipes do not follow the same identical route from supply to sink, just let the hot trickle and it will thaw

[Handyman2007]

And I would suggest that when the weather gets warmer, get under the house and insulate ALL of those pipes. Check to see if there is any place along the pipe where outside cold air is getting to it. It may look insulated but may not be enough. Don't pack insulation tightly around pipes, it defeats the purpose of creating the air spaces that insulate.

[massplumber2008]

Insulating the pipes is not a good idea handyman... ;) Insulating the crawl space and surrounding area itself is!

Insulating pipes is good to reduce heat loss from hot water pipes and to prevent condensation from cold water pipes, but it is NOT good to insulate pipes against freezing. Here, insulating a cold pipe only keeps the pipe cold and lets it freeze quicker. Instead, if someone has an issue with freezing pipes they want to run a thermostatically controlled heat wire around the pipes and then they can insulate the pipe to keep the heat in and reduce the frequency of on/off cycling of the heat wire.

Thanks for posting!

Mark

[ballengerb1]

I agree with Mark, insulate the house not the pipe. Also, I put a thermostatically controlled heat tape on my main in case of a heat issue when I am away from the home.

[Handyman2007]

I just want to say that living in the NorthEast , specifically New Hampshire for 15 years, I have added insulation around the pipes in probably 150 homes on crawl spaces and/ or mobile homes and never had a call back for frozen pipes. If the water temperature never goes below the temperature that it comes out of the ground at (usually around 42 degrees F, the pipes will not freeze.
Just my personal experience.

[massplumber2008]

Not to be a smart-alec Handyman, but I've been to over 150 homes in 32years that did have frozen pipes under insulation and I've discussed this in detail with pipe insulation manufacturers and they present that insulation should NOT be used in the way you are suggesting.. at least not without a thermostatically controlled heat tape as mentioned.

PS... note my name (massplumber).. also northeast with 10 years in Maine and 22 in Boston area.

I take the time to post on this not to correct you as much as it is to be sure that future readers know how pipe insulation is intended to be used.

Thanks again!

[ballengerb1]

I understand the concept but when pipes freeze inside a homes walls it's the wall's fault not the fault of the pipe. If water, at 42 degrees, stand still inside a pipe that is inside a wall cavity that is below 32 the water will freeze. It will freeze eventually no matter how much insulation is wrapped around a pipe, insulation slows heat loss but does not stop it completely. The house insulation must seal out the 32 degree temps. This homeowner should consider moving the pipes from the outside wall if at all possible.

[massplumber2008]

Agree on that, Bob!

[Handyman2007]

ballengerb1: I definitely agree with that concept. That is what I am trying to convey... keep the very cold air AWAY from the pipes and the temperature of the water in the pipes will stay above freezing. And by the way, I am not speaking of Pipe insulation. I am speaking about Fiberglass with a high R value. Pipe insulation only has an R of , the highest I have seen is 5 . Fiberglass bats or faced minimum of 15.

[ballengerb1]

Sorry but that is not how insulation works over a long period. If the temp in the wall is below freezing the insulation will postpone the pipe feezing but it will eventually freeze. It may take days but standing water inside an insulated pipe will freeze if the area around the insulation is below 32 degree. You must boost the insulation ON the wall so the cavity never drops to below freezing. "keep the very cold air AWAY from the pipes and the temperature of the water in the pipes will stay above freezing." Insulation wrapped around a pipe will not achieve what you are picturing here. It only slows the transfer of heat, it will not stop it.