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Can My Main Sewer Line Freeze?

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Posted on: February 15, 2018

One of the worst things that can happen to any homeowner during winter is having a pipe freeze.

Actually… correction.

Having a frozen pipe burst is the worst thing that can happen to any homeowner during winter.

When thinking about one of the most important pieces of plumbing in your home — the main sewer line — can it freeze with a chance of it bursting?

like all plumbing pipes, sewer lines can also freeze and burst

Do Main Sewer Lines Freeze?

The answer to this questions is a simple… yes. It’s possible for all of your plumbing lines to freeze if the conditions permit.

Having a frozen sewer line can be like being in a bad dream. Think about it. This will cause almost every drain and plumbing fixture in your home to back up since there will essentially be an ice clog within the pipe that is connected to each of the other lines.

This bad dream can turn to a nightmare if it happens to burst. Think of all the sewage that will be released into your soil, eventually pooling onto your lawn.

How to Thaw a Frozen Sewer Line

The Best Way
We’re going to be frank here. The best way to thaw your frozen sewer line is to contact your local plumber (cough, cough). Kidding aside, even the smallest of things could cause the pipe to burst.

A professional plumber will be able to best diagnose where the pipe is frozen and how to go about thawing it. It’s always better to be safe than sorry — especially when it involves the most important piece of plumbing in the entire house!

Using Hot Water
Before you attempt this, know that there’s a risk when pouring hot water down the drain. Too hot of water can damage PVC pipes, and hot water could cause pressure to build up — causing the pipe to burst.

If you go ahead with trying this out, heat sink water up on the stove (don’t allow it to boil and get too hot) and pour this down the drain. Running the sink until the water gets hot will just back the sewer line up more, placing too big of a buffer between the sewer line and the hot water.

Since this pipe is underground and only the clean-out is really accessible (if you have one), it can be difficult for the homeowner to thaw their own pipe. This is why we recommend calling a plumber for the best course of action.

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