The Pipes Froze Overnight What to Do

Where I live in Virginia is a lovely place with moderate four season weather. Though we have snow, it usually doesn’t stay on the ground too long because it is rare to have more than a week of freezing weather. This past week artic cold descended on much of the mid-west and low single digits arrived in Virginia. Nothing ever dies on the internet, so my home phone number and email address are out there and I got lots of calls for what sounded like frozen pipes from near and far.

Once you have a frozen pipe, the best strategy is to slowly warm it up and let it melt. A frozen pipe does not have to mean a burst pipe, but the only way you will know if the pipe has burst (other than ripping out the ceiling or wallboard) is to defrost the pipe and run the water and look for the leak. Water expands when it freezes applying force in all directions, but damage done by the ice usually occurs at elbows and joints where the force is constrained. Some plumbers believe that toilet valves and pressure tanks (used in homes with private wells) can allow a plumbing system to absorb the increased pressure and reduce the likelihood of a burst pipe.

If on a very cold day you turn on a faucet and either get nothing or just a trickle comes out, suspect a frozen pipe. Usually, this happens when the temperature drops overnight and there was no water being used. If you have a frozen pipe you need to identify which part of your piping is frozen. If it is the supply line, there will be no water to any part of the house. If however, after checking you find that there is water in parts of the house, then the frozen pipe is on an exterior wall or above an unheated space.

The likely pipes to freeze are against exterior walls of the home, or are exposed to the cold, like outdoor hose bibs, and water supply pipes in unheated interior areas like basements and crawl spaces, attics, garages, or kitchen cabinets. Pipes that run against exterior walls that have little or no insulation are also subject to freezing.

If there is no water anywhere, then it is either the well or the supply line into the house. In sub-zero weather wells with separate well houses can freeze. Back in the day, an inefficient 100 watt incandescent bulb provided enough wasted heat to keep a well house from freezing, modern efficient bulbs do not. You are going to need to put a heat source in the well house to warm it up.

A well with an immersion pump and a couple feet of pipe above ground and exposed might also freeze. Covering an exposed well pipe with an insulating tarp can help it warm up, though the last time I had to help someone do that we ended up using an electric blanket under a black mover pad using the electric heat and the midday sun to warm up their well.

If it is the supply line from the well then you need to warm the well house or the well pipe and try to warm the area where the pipe enters the home, for example under the garage. Hopefully, the pipe froze in the most vulnerable areas at the two ends. If your pipe is not buried deep enough, there is simply nothing you can do but wait for the weather to warm up.

Once you had addressed the well house or well head, then you need to do is raise the temperature in the garage or where the pipe enters the house (it might be a crawl space). A ceramic heating cube ($39 from Lowes) in the garage or crawl space can help warm up a frozen pipe entering the home or a water pipe that runs above of adjacent to a garage.

To defrost interior pipes the first thing you need to do is raise the temperature in the house to at least 68 degrees. Open the cabinet doors under the sinks, and ceramic heating cubes in any bathroom that is adjacent to an unheated space (like a dormer, over a garage, etc.). You need to get the pipes warm enough for the ice to melt. Open a faucet a touch in the sinks or tub. The open faucets are intended to offer another source of relief of pressure as the pipes defrosted and allow the water to flow as the pipe defrosted. Basically, you need to get the pipes warm enough for the ice to melt. If you have plastic piping that is considerably more tolerant of freezing than copper pipes. There is a real shot that a plastic pipe can freeze without bursting if all the connections and elbows are sound.

Okay, what next. Patience. It took me almost 24 hours to defrost my pipes the last time I had to do it. With any luck, when the water starts to flow, it will be into the sink and not a burst pipe. Repeatedly freezing and thawing a plastic pipe can cause it to stress fracture. So, in the future, plan for freezing weather. Turn on the heating cube in the garage open the cabinet below the sink and run the extra heaters overnight to prevent the pipes from freezing in the first place. For those of you with separate well houses that are far more likely to freeze overnight and no longer have access to the 100 watt bulb that kept the old below grade well house warm enough during New England winters, there are Thermocubes, heating tape and heating pads.