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How to Prepare Your Home for Subzero Weather

Put these tips to use when really nasty subzero weather blows in.

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FH18DJF_583_07_002_ thermostat

Bypass Your Thermostat

So during extreme cold, bypass your thermostat’s program, take it out of setback mode and leave the temperature steady. You may even want to turn it up a couple of degrees.

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FH18DJF_583_07_012_preview space heater to prevent frozen pipesFamily Handyman

During a Cold Snap Open Kitchen Cabinet Doors

Being behind closed doors, kitchen plumbing frozen pipes are vulnerable, as the heat from the rest of the house can’t reach them. Open the cabinet doors to allow heat to circulate into the cabinets. A fan or portable heater pointed inside the cabinet also helps circulate warm air.

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FH18DJF_583_07_014 running faucetFamily Handyman

During a Cold Snap Leave Faucets Running

A trickling faucet acts as a relief valve for the pressure that builds up if frozen pipes do occur. That pressure relief can prevent frozen pipes from cracking. A slow trickle is all you need. It’ll bump up your next water bill a bit, but compared with major home repairs, that’s an easy price to pay. Don’t leave a faucet running if the drain is on an exterior wall, though; the drain can freeze, causing the sink to overflow.

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Clean and dirty furnace filters, changing furnace filterFamily Handyman

Replace Furnace Filter

A dirty furnace filter will make your furnace work harder to keep your home warm and the last thing you want is a furnace problem in sub-zero weather.

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Are the Registers Open or Blocked?

Are the Registers Open or Blocked?

Every furnace technician has a story about a cold room that was cured by opening a register or two. Don't make yourself the star of one of those stories. Rearranging the furniture or shoving a rug aside can also block airflow. And here's one reason you might actually want to close your heat registers. Plus: Check out the 12 best ways to heat your garage in winter.

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Cold House? Are the Radiators Clear?Family Handyman

Cold House? Are the Radiators Clear?

Whether you have electric or hydronic baseboard units or old-fashioned radiators, they won't throw maximum heat unless air can flow through them. If you move the bed against a baseboard unit or toss a blanket across a radiator, the room might get chilly.

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Is the Radiator Air-Locked?Family Handyman

Is the Radiator Air-Locked?

If you have a hot-water radiator that's not heating, the cause is usually trapped air. Getting rid of it is simple. Use a radiator key, 1/4-in. 12-point socket or a flat screw- driver (depending on your valve type) and slowly turn the valve counterclockwise until water drips out. This will release trapped air and let hot water flow. While you're at it, repeat the process on your other radiators. Bleeding the radiators will lower the pressure in your system, so you might have to slowly add water to increase the pressure. Do this by opening, then closing, the valve on the water pipe above the boiler.

If you're unfamiliar with your system, call a pro. How much pressure you need depends on how high the water has to rise. The basic rule is 1 lb. of pressure for every 2 ft. of rise. Your gauge may read in pounds, feet, or both. A basic two-story house, with the boiler and expansion tank in the basement, needs 12 to 15 lbs., or 25 to 30 ft., of pressure.

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Electric Heat CableFamily Handyman

Consider an Electric Heat Cable


An electric heat cable is good protection during cold spells. A thermostat switches on the heat only when the temperature drops, so heat cable won’t waste electricity when it isn’t needed. But if you need to protect lots of pipes for long periods, heat cable is an expensive solution.

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BoilAndrei Kuzmik/Shutterstock

Boil a Pot of Water

Whether you use a tea kettle or an open pot, boiling water will help warm up your kitchen. And, when you’ve got that piping hot water, make your favorite tea and warm yourself from the inside. Here is another surprising way to use boiling water!

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shutterstock_150550232 aluminum foilSergiy Kuzmin/Shutterstock

Use Foil

If you have a radiator attached to an external wall, use some aluminum foil behind the radiator. The reflective nature of the foil will prevent heat from disappearing through the wall and instead will reflect it back into the room. Here are 10 ways to heat your home during an emergency.

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stopperAmazon

Try a Fireplace Plug

You can lose up to 20 percent of your home’s warm air through leaks in a loose fireplace damper. A fireplace plug can help you seal the flue to keep that warm air in. Fireplace plugs come in different sizes so be sure you know what size you need before purchasing. Is it time to clean your chimney? This is the ultimate cleaning guide.

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Warmer Amazon

Grab a Hot Water Bottle

Tired of getting in a cold bed at night? Fill a hot water bottle (with hot water, of course!) and place it at the foot of your bed, underneath the blanket. It will help keep your feet warm. Freshen your linens without chemicals.

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dogDmussman/Shutterstock

Cut Down on Mini Drafts

You can lose a lot of warm air through mail slots and doggy doors. When possible, keep these areas covered when subzero weather hits. You can use a wool blanket to plug an animal door or even an old towel to close up a mail slot when the temperature really drops. Here are 42 home security nightmares lurking around your home.