Keeping Furnace Vents and Gas Meters Clear of Snow

4 min read · Thames Valley Snow, London, Ontario

Why side-wall vents matter

Many newer homes in London have a high-efficiency furnace, water heater or boiler that vents through the side wall instead of up a chimney. You will usually see two white or grey plastic pipes a short distance above the ground: one pulls in fresh air for combustion and the other pushes exhaust out.

Because these pipes sit low on the wall, they can be covered by drifting snow, by snow thrown off a roof, or by a snowbank that builds up over the winter. If the intake or exhaust is blocked, the appliance may shut itself off as a safety measure, which can leave you without heat or hot water on the coldest night of the week. In the worst case, a blocked exhaust can push combustion gases back toward the house.

Carbon monoxide alarms are your backup

Carbon monoxide has no colour or smell. Ontario law requires working carbon monoxide alarms in homes that have a fuel-burning appliance, a fireplace or an attached garage. Test them, replace batteries on schedule, and check the replacement date printed on the alarm. A clear vent is the first line of defence; a working alarm is the second.

How to check vents after a snowfall

• Find your vent pipes now, before the first big storm, so you know where to look when the yard is white.
• After heavy snow or strong wind, walk over and look. Brush snow away from the pipe openings by hand or with a soft broom.
• Look for frost or ice building up around the exhaust opening. A small amount of frost can be normal; a growing plug of ice is not. If ice is closing the opening, call your heating contractor rather than chipping at the plastic pipe.
• Do not pile shovelled snow against that wall. Pick a different spot for your own snow and for anything you clear off the deck.
• Many manufacturers and installers recommend keeping a clearance of about 30 cm between the vent and the expected snow line. Your installer can tell you what applies to your appliance.

Gas meters need room too

The gas meter and the regulator attached to it are built for outdoor weather, but heavy snow and ice can still cause problems. Ice on the regulator vent can affect how gas flows into the house, and a meter buried under a bank is easy for a plow, a snowblower or a shovel to hit.

Enbridge Gas asks customers to keep meters clear of snow and ice. The safe way to do it is gently with a broom or by hand. Do not kick, hit or chip ice off the meter or its piping, and never use a shovel blade on it. If the meter is encased in ice, or you smell gas (the added odour is like rotten eggs), leave the house and call the gas company's emergency line from outside.

What a snow crew does and does not do

A seasonal snow removal plan clears your driveway, and with the walkway add-on the path to your door. Point out where vents and meters sit so snow is piled away from that wall. Crews do not clean, clear or service vents or gas equipment; those belong to you and your heating or gas provider.

What a crew can do is keep the access clear. A cleared walkway around to the side of the house makes it easy and safe for you to get to the vent and meter after a storm, instead of wading through knee-deep snow on an icy path.

Mark them before winter

Snow changes the shape of a yard quickly. A tall stake or a reflective marker near the vent pipes and meter helps you find them under fresh snow, and lets anyone clearing the property see what to avoid. Mention them when you book, along with any other hidden items such as window wells, garden edging or a low wall.

A quick routine for storm days

• Before bed on a snowy night, look at the forecast for wind and drifting.
• In the morning, check the vents and meter before you leave for work.
• After a freezing rain event, look for ice on the meter and the exhaust opening.
• If the furnace or water heater shuts off during a storm, check the vents first, then call your heating contractor.

Book the clearing, keep the routine

A seasonal contract runs from December 1 to March 31 and starts automatically at 5 cm, with a timestamped photo after every visit. Walkway and steps clearing starts at $150 and seasonal salt is $175, including freezing rain and refreeze visits. See residential snow removal and walkway and steps.

Every Thames Valley Snow quote is measured from City of London maps and aerial imagery, and you get a fixed price within 1 business day. Ask for a free quote, or call or text (548) 888-8702.