What to Do If Your Furnace Stops Working in Winter
It’s 2 AM, the temperature outside is -15°F, and you wake up shivering because the house has gone cold. Your furnace has stopped working. In the Brainerd Lakes Area, this isn’t just an inconvenience, it’s a situation that requires prompt, calm action.
Before you panic, there are several things you can check yourself that might get your heat back on quickly. And even if they don’t, there are steps to take to keep your family safe while you wait for a technician. Here’s the complete guide to handling a winter furnace failure.
Step 1: Don’t Panic, Start With the Simple Stuff
Many furnace “failures” aren’t failures at all, they’re simple issues that can be resolved in minutes. Before assuming the worst, check these basics:
Check the Thermostat
- Is it set to HEAT (not cool or fan only)?
- Is the temperature set above the current room temperature?
- Are the batteries dead? A thermostat with dead batteries won’t signal the furnace to run. Replace them and see if that restores heat.
- Is the display on? If the thermostat is completely dark and it’s a wired model, check the circuit breaker.
Check the Circuit Breaker
Your furnace runs on electricity even if it burns gas. Find your electrical panel and look for:
- A breaker labeled “Furnace” or “HVAC” in the tripped position (usually halfway between on and off)
- Reset it by switching it fully off, then fully on
If the breaker trips again immediately, stop, there may be an electrical issue that needs professional attention.
Check the Furnace Power Switch
There’s usually a power switch on or near the furnace that looks like a standard light switch. Make sure it’s in the ON position. It gets bumped off accidentally more often than you’d think.
Check the Filter
A severely clogged air filter can cause the furnace to overheat and shut down on the safety limit switch. If your filter looks like a gray wool blanket, replace it, then give the furnace 20–30 minutes to cool down before trying to restart it.
Check the Gas Supply
- Is your gas turned on? (The shutoff valve on the gas line to the furnace should be parallel to the pipe, not perpendicular.)
- If you have propane, is your tank empty? Check the gauge.
- Are other gas appliances in the house working? If your stove won’t light either, you may have a gas supply interruption, call your utility.
Step 2: Try Restarting the Furnace
If the basics check out but the furnace still isn’t running, try a manual restart:
- Turn the thermostat down (or to OFF)
- Turn off the furnace power switch
- Wait 30 seconds
- Turn the power switch back on
- Set the thermostat back to HEAT at your desired temperature
- Listen for the furnace to attempt to start
Modern furnaces make an attempt, wait, make another attempt, and then lock out if they can’t achieve ignition after 3 tries (this is a safety feature). If the furnace locks out, you’ll often see a blinking LED error code on the front panel. Many furnace models have a legend on the inside of the door explaining what different blink patterns mean.
Step 3: If the Furnace Won’t Start, Focus on Staying Warm
Once you’ve established that the furnace isn’t coming back on on its own, shift your focus to keeping your household warm and safe while you wait for help.
Contain Heat in Key Rooms
- Close the doors to rooms you don’t need to heat
- Gather family (including pets) into one or two central rooms
- Use interior rooms, they retain heat better than those with exterior walls
Use Safe Supplemental Heat Sources
- Electric space heaters are the safest portable option. Keep them at least 3 feet from anything flammable and never leave them unattended.
- Fireplaces and wood stoves, if you have one that’s operational, now is the time to use it. Make sure the flue is open before lighting.
- Extra blankets, sleeping bags, and warm clothing, layer up and don’t underestimate the difference a good blanket makes.
What NOT to Use for Heat
- Never use your gas oven or stove burners to heat your home. This is a serious carbon monoxide risk.
- Never use propane or kerosene heaters indoors unless they are specifically rated for indoor use, and even then, ensure ventilation.
- Never use a generator, charcoal grill, or camp stove indoors. These produce deadly amounts of carbon monoxide.
- Never use your clothes dryer as a heat source by running it with the door open.
Step 4: Protect Your Pipes
In the Brainerd Lakes Area, one of the biggest concerns during a heating outage is frozen pipes. Water damage from burst pipes can be catastrophic.
To protect your pipes:
- Keep cabinet doors under sinks open so warmer air circulates around the pipes
- Let faucets drip slightly, moving water is harder to freeze
- Know where your main water shutoff is. If pipes start freezing, you may need to shut off the water supply.
- If the house is going to be below freezing for an extended period, consider shutting off water and draining the lines
In extreme cold, pipes in exterior walls and unheated spaces can freeze within a few hours. Don’t wait until pipes burst to take action.
Step 5: Call for Emergency Service
Once you’ve stabilized the situation, call for emergency HVAC service. When you call, have the following information ready:
- Your furnace brand, model, and approximate age (often on a sticker inside the furnace door)
- The error code if the furnace is displaying one (blink pattern)
- What you’ve already checked (thermostat, breaker, filter, gas supply)
- Current indoor temperature and how quickly it’s dropping
- Any unusual sounds, smells, or visible issues
This information helps the technician come prepared with the right parts and knowledge of your system, potentially turning a two-trip repair into a one-trip fix.
Step 6: Know When to Leave
If indoor temperatures drop below 50°F, it’s time to consider relocating temporarily, especially if you have infants, elderly family members, or individuals with health conditions. Options include:
- A hotel or motel
- A friend or family member’s home
- A community warming center (check local news or your city/county website)
If you leave the home, leave the heat set as low as it will go (not off, many thermostats have a “emergency heat” or minimum setting), keep cabinet doors open, and let faucets drip. Don’t completely shut off the heat if there’s any functioning capability remaining.
After the Repair: Prevent It From Happening Again
Once a technician has restored your heat, take a few steps to reduce the chances of a repeat:
- Schedule annual furnace maintenance before each heating season, ideally in September or October
- Replace your filter every 1–3 months
- Install a smart thermostat that can alert you if indoor temperature drops unexpectedly
- Get a carbon monoxide detector on every floor if you don’t already have them
- Keep the technician’s number saved, Maverick’s Heating & Air is here for emergency calls
A winter furnace failure is stressful, but it’s manageable if you stay calm and take the right steps. Save our number in your phone so you’re ready if it happens, we offer emergency service in the Brainerd Lakes Area.