Gas Furnace Safety: Is Yours Safe to Use This Winter?

A gas or propane furnace is safe when it is clean, properly vented and inspected every year. Carbon monoxide is the real risk, so pair an annual tune-up with working CO detectors on every level of your home.

Why furnace safety matters more in our winters

From November through March, furnaces in Upstate New York and Vermont run for hours at a stretch. Windows stay shut, chimneys and vent pipes ice up, and a furnace that sat idle all summer is asked to run flat out on the first below-zero night.

That is when small problems turn into safety problems: a cracked heat exchanger, a blocked flue, or a burner that is not firing cleanly. Natural gas and propane burn cleanly when everything is adjusted correctly. When it is not, the byproduct is carbon monoxide (CO), which you cannot see or smell.

Carbon monoxide: what to know

CO is produced any time a fuel burns. A healthy furnace sends it up the vent and outside. A damaged heat exchanger, a blocked or disconnected vent, or a backdrafting appliance can push it into the living space instead.

Low-level exposure feels like the flu: headache, nausea, tiredness, dizziness. If everyone in the house feels sick at once, or symptoms ease when you leave, treat it as CO. Get outside, call 911, and do not go back in until responders clear the house.

Put a CO detector on every level and near bedrooms, test it monthly, and replace it on the date printed on the unit.

Warning signs your furnace needs attention

• A yellow or flickering burner flame instead of steady blue
• Soot, rust streaks or moisture around the furnace or vent pipe
• A burning or metallic smell when it starts up
• Short cycling: it turns on and off every few minutes
• Unusual banging, rattling or whistling
• Rooms that are noticeably colder than before

Any of these is a reason to shut the furnace down and call for service rather than wait to see what happens. A written quote comes before any repair work, so you know the cost first.

What a safety inspection covers

A real inspection is more than changing a filter. Superior CO-OP HVAC technicians check the heat exchanger, burners, ignition, flue and venting, gas pressure, and safety switches, then clean what needs cleaning and test CO at the equipment.

Our per-visit tune-up for a gas or propane furnace starts at $210.83. If you would rather not think about it, maintenance plans schedule the visits for you. Learn more about our furnace repair and maintenance service for all brands.

Propane and older furnaces need extra care

Many rural homes outside the natural gas footprint run on propane, and a lot of Capital Region and Vermont houses still have furnaces from the 1990s or earlier. Older units are more likely to have corroded heat exchangers and aging venting, and they run less efficiently too.

Keep the area around the furnace clear, never store paint, solvents or gasoline next to it, and keep outdoor intake and exhaust vents free of snow and ice after every storm. If the furnace is older than about 15 to 20 years and needs a major repair, compare the cost with replacement using our repair or replace guide.

Considering a heat pump instead?

A heat pump has no flame and no combustion byproducts inside your home, so the CO question goes away for the part of the house it heats. Mitsubishi Hyper-Heat units deliver 100% Capacity to -13°F and operate down to -35°F, which covers our winters.

Many homeowners keep the furnace as backup and let the heat pump carry most of the season. See cold-climate heat pump vs furnace or run the two-minute Heating Cost Calculator to compare your fuel costs.

A simple safety routine for the season

Build a short routine and repeat it every fall. First, schedule the professional inspection. Second, test every CO and smoke detector and replace any past their date. Third, walk the house and look at the furnace room: no storage piled around the unit, no paint cans or gas cans nearby, and no rust streaks on the vent pipe.

Then, once the heat is running, pay attention in the first week. A new smell, a new sound or a pilot or burner that looks different is the furnace telling you something. Call early. A short service visit is far cheaper than a failed heat exchanger discovered in the middle of a cold snap, and a written quote comes before any repair work so there are no surprises.

If you rent out part of a home or own a seasonal camp, apply the same checklist before each stay.

Frequently asked questions