The winter checklist: getting a house through the cold months

If the fall list got done, winter is mostly a matter of paying attention. The house is working harder than at any other time of year, and the things that go wrong announce themselves early if anyone is listening. Here is what to watch, what to do when the forecast turns, and what to leave alone.

Every month

• Change the furnace filter. A furnace runs more hours in January than in any other month, and a loaded filter starves it of air. It is the cheapest thing you can do for the equipment.
• Test the smoke and carbon monoxide alarms. Winter is the season for both.
• Walk the outside after any big storm and look at the roof edge, the gutters and the vents. Look for icicles, which are a sign, not a decoration; see the ice dam piece in this section.
• Check that the furnace and water heater exhaust vents on the outside wall are clear of snow. A high-efficiency furnace vents in plastic pipe near the ground, and a drift over it shuts the furnace down or, worse, sends the exhaust back inside.

When a hard freeze is coming

• Open the cabinet doors under sinks on outside walls so warm air reaches the pipes.
• Let the faucet farthest from the main drip, cold side, a pencil-lead stream. Moving water freezes far less readily.
• Keep the heat on, at least 55 degrees, even if you are away. Every winter's flood stories include a thermostat set to save money.
• Know where the main shutoff is and that it turns.

Snow and ice

• Keep the walk and the steps clear and salted. Most winter injuries at home are falls, and a lawsuit from a delivery driver is a real thing.
• Do not chip ice off the roof edge or the gutters. It takes the shingles with it. A roof rake used from the ground to pull snow off the lowest three or four feet does more good and no harm.
• Watch flat and low-slope roofs. A foot of wet snow is a serious load, and a porch or carport roof that sags is a call now.

The heating system

A furnace that short-cycles, runs constantly without keeping up, makes a new noise, or leaves one room cold that was not cold last year is telling you something. So is a heat pump that runs its backup heat more than it used to. Early in the season a Pro can come in a day; in the first week of January every Pro in the county is booked.

Humidity

Cold outside air is dry, and a heated house in January often sits well under 30 percent humidity, which is why the floors creak, the woodwork cracks and everyone gets shocks. A humidifier on the furnace, set around 35 percent, fixes it. Set it higher and the windows will fog and the sills will get wet, which is the other problem.

What to leave alone

The gas line, the inside of the furnace, anything on the roof, and any electrical work beyond changing a bulb. Winter is when people get hurt doing the jobs a Pro would have done in an hour.