View Full Version : Who knows something about frozen pipes?

01-18-2005, 08:41 AM
I turned on the hot water to the kitchen sink this morning and nothing came out. Cold water is fine everywhere. My setup is: Water main comes into the house (on a slab, no basement). The water heater is to the immediate right. On the left is a vanity/sink. I'm getting hot water out of that sink. Then there's the toilet. Then an oversized shower, which is on the corner of an outside wall. No hot at the shower. No hot after it goes along that wall into the kitchen, either. And the hot line between the Sink & shower is exposed to the inside for most of the way before it goes into the wall, so a freeze there is unlikely. Pipes are copper. Just had it all replumbed about 5 years ago. That includes the main.

I turned the pump and water heater off and put my ear up to the wall and don't hear any running or dripping water. I do get a steady but slow drip at the kitchen tap when I have the single handle turned all the way to hot.

With the help of a space heater, I've had the temp in the bathroom up in the 80's for a couple of hours. It's been in the -5 to -10 degree range at night for the past 4-5 days. At 8:30 a.m. it's -2 with a high of 20 predicted and temps rising overnight to 30. I've had the cupboards open in the bath and kitchen and the shower curtain open for all of those cold nights. I do turn the furnace down to 60 at night though. I checked around that wall outside and didn't see any signs of water there. I think I've covered everything.

Should it be taking this long? There's only 20 or so inches of pipe between where it enters the wall behind the shower, and where it branches up to the shower head. I've never had to deal with this before. Is it time to call a plumber or am I just being impatient? Could it be a completely different problem?

01-18-2005, 09:07 AM
Are the exposed pipes hot?

Turn up the thermostat on the water heater.

If the hot water tap in the kitchen drips, it is hard to see how an ice blockage could last long.

01-18-2005, 09:25 AM
I ran the hot water at the vanity a bit and checked the pipe. The part under the vanity is toasty warm until it leaves the vanity. There it goes along an outside wall and gets from lukewarm to cold as it gets closer to the shower. Right now I have the space heater on the spot where it enters the shower.

01-18-2005, 09:33 AM
If water is coming into your home alright and no portion of the lines are exposed, I don't think it's a frozen pipe.

You said you turned off the pump. Is a pump required to get water to all your outlets? Then my guess is a pump problem. You still might be able to get hot water from some outlets due to gravity.

Can you tell if your water heater is refilling? If not, then the blockage may be before it and again, some outlets could get hot water by drainage but others couldn't. Try emptying the tank by running enough water from one of outlets that now has hot water.

01-18-2005, 09:44 AM
Can you tell if your water heater is refilling?

I just went in to make sure about that and the blockage cleared. I ran the hot for a while so whatever was in there melted all the way. Looks like I just needed to wait a little longer. I guess I'll have to keep it a little warmer in the house on those below zero nights.

Thanks for all the suggestions. At least checking all that stuff kept me busy while I was waiting.

01-18-2005, 09:52 AM
My guess is that the hot water leading to the shower is frozen. It may thaw enough to flow but it could take hours. Its best if you are there because, if the freeze caused a braek, it won't leak until it thaws.

On very cold nights you might consider going to the furthest tap from the water heater (from your description it sounds like its the kitchen sink) and turning on the hot tap to a steady drip. What that will do (besides waste some hot water) is keep a small amount of warm water flowing through the pipe on very cold nights. The flowing water will carry a small amount of heat with it and the flow itself will resist icing up.

You might also consider not turning down the furnace at night.

01-18-2005, 09:53 AM
You posted as I was writing my relpy. I'm glad the problem solved itself. Stay warm. :)

01-18-2005, 10:00 AM
The waters flowing--excellent.

You might want to insulate all the pipes, hot or cold, you have easy access to--foam type tubing or insulating type. In the past I've had occasional frozen pipes. Last summer I finally did the pipes and I haven't had any problem so far and the weather has been colder than average.

01-18-2005, 12:32 PM
Sixty is far too low for setback when the weather is below freezing. By the time the thermostat senses 60, the pipes in the wall are at freezing. When it gets below 32, I set the thermostats for 68 at night (depending on the zone routing). The one time I didn't, I had a freezeup on the living room loop. $250 later (weekend rates), the plumber thawed the line for me.

01-18-2005, 12:52 PM
We have had similar problems several times in the past. Interestingly, it is often the hot water that freezes first - instinct would tell us that the cold water pipe is colder to begin with and should freeze first, but it just doesn't hold up in practice. Some friends have proposed that the hot water freezes faster because the water heater has driven off gases in the water.

Anyhow, what can you do? Well, the first thing is to thaw the pipes. With a minor freeze, you should open the tap, then start heating things up working back down the line to the water heater. We find a hair dryer is very useful here - small, directional, and pretty effective. If the freeze is a major one (hot and cold both frozen, several taps involved), it's time to get in touch with your plumber. He has a pipe heater, sort of like an arc welder, that he hooks to the pipes - one end where the pipes enter the house, the other at the furthest outlet. Plug it in and run current through the pipes, and they will heat up. Then he'll give you his bill, and it's your turn to heat up. :eek: But it's still cheaper than paying him to replace burst pipes. Fortunately, you have copper pipes, and this device will work. Plastic pipes are another problem.

Having fixed the blockage, the next question is why did this happen, and what can we do to prevent it happening again? Check for obvious air infiltration first - can you see any holes where cold air might be getting in? One trick is (at night) to take a work light, stick it in as far as you can in the pipe chase, then go outside and look for glimmers of light - cracks, holes in the wall, vents, anything along those lines. Patch/insulate any problem areas. You really have two options - keep the cold air out in the first place, or bring in more heat from somewhere. Pipe insulation might work if you have access to the pipes, e.g. in a basement or crawl space, but in the walls it's going to be tricky, if not impossible without doing some demolition - too many brackets holding the pipes in place, too many joints and elbows.

We have had problems with the pipes freezing in the upstairs bathroom. Our solution is to leave on the over-sink light in the kitchen, right below the bathroom. The light gives off enough heat to keep the pipes from freezing. Another trick is to put some vents in the kitchen ceiling, allowing heat to get into the space between the kitchen ceiling and the bathroom floor - which is where the pipes run. And, as has been suggested by others, watch the forecast - if it's going to get really cold, don't lower your thermostat at night.

You can buy electrical "heat tapes" that wrap around the pipe and are plugged in to prevent freezing. I find these are practical only in certain limited situations and locations, but if you have a recurrent problem always in the same place, they might do the trick.

01-18-2005, 01:19 PM
To prevent later problems I'd get some foam pipe insulation.Its pretty cheap and sold in 3 or 4 foot lengths. I believe you stated that the pipes are exposed along the wall? Insulate the outside wall side of the pipe cutting off enough of the foam so the inside of pipe is exposed to warm inside air.
Also keeping a fan running will move that cold trapped air that is causing the problem.

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