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Sink Drainage Problems in Cold Weather



Sink drainage problems can develop as a result of cold and freezing weather, and existing sink drainage issues can be compounded by freezing temperatures. In any event, these problems should be investigated as quickly as possible to prevent extensive plumbing problems and water damage.

Frozen Drain Pipes

Frozen pipes are one of the primary causes of sink drainage problems. Frigid temperatures combine with water to produce ice, which then expands in the pipes. This condition is more likely when the home’s thermostat has been turned down, which creates an even colder environment, resulting in either slow or backed-up drains.

Clogged Drain Pipes

Cold weather can also cause sink drainage problems through clogged or frozen drain pipes. Shampoo and other toiletry items poured down bathroom sinks, as well as grease and other waste poured down kitchen sinks, have the potential to clog sink drains even during warm weather. However, during cold weather, these liquids can solidify, increasing the probability of clogs.

Clogged Vent Pipes

During winter months, clogged vent pipes can also cause sink drainage problems. Vent pipes are located on the roof of the home and can become clogged in one of two ways. General debris or dead animals on the roof can block the pipes and cause slow drainage in the house; however, in rigid weather, snow or ice can settle in the pipe gaps around the debris and form a solid obstruction which prevents water from draining. Even if there are no existing objects trapped in the vent pipes, snow or ice can still accumulate and form a frozen, compact mass, which obstructs water in the sink from draining.


The type of treatment will depend on the severity and location of the problem. If may require heating the sink area and running hot water until the sink fills up. Then use the wet-dry vac to remove the water from the sink. Continue this process, but be advised that it may be one to two hours. If the problem is the vent, the solution is more complex and involves getting on the roof and using a garden hose to flush the frozen water out.


The best strategy is to avoid sink drainage problems. Don't pour oil, grease, debris, or food items down the drain - regardless of the season, but especially during winter months. Use strainers to catch food and hair. In addition, flush the garbage disposal with plenty of water to prevent a backup. And, as much as possible, make sure that the pipes are insulated or can receive heat - which could mean placing a small space heater close by when the temperature freezes, or at least opening the cabinet doors so the indoor heat can better circulate in that area.

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