From the ground, or if you can see the cap from a window, visually inspect to see if you can spot ice build-up. Don't go on your roof. If your toilet is slow or gurgles, this can also be a sign that the vent is plugged.
During extended periods of very cold weather, sewer gas containing water vapor will condense, then freeze to form a frost layer in the exposed uninsulated end of the vent pipe. This frost layer can seal the pipe partially or fully, forming a plug. Hard, drifted snow also can plug the end of the vent pipes.
Warning Sign #1: Gurgling Toilets and Drains
Have you noticed a gurgling sound coming from your toilet or sink after you flush? If your plumbing vent is clogged, air can't escape your plumbing system the way it normally would, so it finds the nearest exit—your toilets and drains—and makes noises at it escapes.
Hot water: Running hot water creates steam and heat that rises through your vent pipe. Turn on a faucet on the uppermost floor of your home and allow it to run hot water for a while. The heat the water creates may be enough to melt any snow or ice that's clogging the vent.
Your sewer releases gases through a vent stack located on your roof. After a really heavy snow, that vent can become blocked and prevent air pressure from regulating your system. Smelly, potentially dangerous gases can back up into your living space if the problem isn't addressed quickly.
To do so, gently apply heat to the frozen areas. A blow dryer is a good option (use caution, go slowly, and don't use an open flame). For hidden pipes: Use an infrared lamp to target frozen areas. You may need to make an opening in your wall to access the pipe.
First, check under the vents in the room. See if you notice any larger objects obstructing the duct. If it is easily removable, clean out the duct and monitor the temperature of the room to see if it levels out with the rest of your home.
If you have a two-story home, go upstairs to locate the pipe. You can verify whether a pipe is a vent pipe by listening as someone flushes the toilet. If the pipe amplifies the flushing sound, it's likely the vent pipe. To find the plumbing vent on the roof, look for a pipe extending about six inches from the roof.
Most frozen icy waste removal jobs can be completed using the cold water supply from a garden hose. Heated water is usually not required. Use a sewer jetter with a nozzle that has a forward jet to help penetrate the icy clog.
A foul smell from the drain or faucet is a less-obvious warning sign. Odors are unable to filter out of the frozen pipe and instead are forced back into the home's faucet. No water or a slow trickle when a faucet is used. Whistling and banging coming from pipes, or strange bubbling sounds when you flush a toilet.
Gurgling sounds: Unusual noises coming from drains or pipes may indicate ice blockages. Odors: Foul smells inside or outside your home near the septic area can signal a problem. Frozen ground: Unusually frozen or frost-heaved ground over septic lines or the tank area may indicate freezing within the system.
The first and most obvious sign you might have a frozen drain pipe is visible frost on the pipe itself. When there is frost forming on the outside of a pipe, chances are that the pipe is completely frozen on the inside. In this situation, shut off the water to that part of the home and immediately call a plumber.
Sewer lines can freeze, even if they are buried below the frost line. Extremely cold weather can send ice into drain systems. If left unused, without warm wastewater flowing through sewer lines, the pipes can freeze and burst.
When your plumbing vent pipe is clogged, you put yourself and your loved ones at risk. You'll likely know it's clogged if there's a gurgling sink or foul odors inside your house. Left unchecked, sewer gasses can seep into your home to cause sickness or even lead to explosions.
It will look like a vertical pipe running through the roof. The vent pipe works hand in hand with the drainage pipes. When the drainage pipes carry waste out of your home, the vent pipes supply fresh air to the plumbing fixtures, so they can repeat the process and continue moving waste out of your home.
Apply any household spray cleaner on the PVC pipe and allow it to soak. Next, use a soft-bristled brush to gently scrub away dirt particles from hard-to-reach areas inside the PVC pipe. Wipe down the PVC pipe with a lint-free cloth. Repeat the process as necessary.
How do I test my plumbing vents? You can do a simple DIY test by putting your hand over the roof vent pipe while someone flushes a toilet. You should feel suction on your hand when the toilet is flushed if the vent is clear. No suction indicates an obstruction in the vent.
Every few years, assuming you can get up on your roof safely, you should put a garden hose down the roof vent pipe and run water down the pipe for a few minutes to wash out any accumulated dust, tree debris, or even bird poop. If you do this, be sure you put sentries within the house to spot any leaks.
Less reach: You may find that your cold or hot air from the air conditioner or furnace does not get as far as it should when your air vent is blocked. Your home's temperature may feel inconsistent, with hot or cold spots. Stagnating air: With reduced airflow, you will have stagnated air through the home.
Running hot water from one of your faucets will create warm vapor that can help melt the ice. Opening a door or vent to your attic can warm up the stack, but will increase your heating bill temporarily. Periodically add warm water to drains that aren't used often, to keep the trap full.
Frozen pipes will eventually thaw on their own, but it could take days or even weeks. If New York City is experiencing a brutal cold snap, the temperature could stay below freezing for many days. Meanwhile, the water in the pipes could be expanding.
For Pipes Located Underground:
Believe it or not, thawing underground frozen pipes doesn't have to involve digging. Instead, you just need a water jet to blast the ice out of the way from underground.