Key Takeaways
- For household safety, turn off the furnace power and smell for gas or burning odors prior to troubleshooting. Evacuate if you detect any.
- Save your heat, close off rooms and bunch everyone into one insulated space. Employ blankets and layered clothing to keep warm until your heat is back up and running.
- Check and clear exterior vents of snow or ice, intake and exhaust pipes, and check circuit breakers and thermostat power to eliminate common causes of a winter shutdown.
- Give it a controlled system reset. Turn off the thermostat and breaker for a few minutes, then restart. Make sure to note any error codes, noises, or repeated failures to the technician.
- Employ secure temporary heat sources such as UL-listed space heaters or a ventilated fireplace, not indoor grills, and keep flammables far from all heat.
- Call a trusted HVAC pro for gas leaks, CO alarms, repeated shutdowns, strange noises or if basic troubleshooting doesn’t work. Note symptoms and accessibility ahead of time.
If your furnace stops working during a snowstorm, don’t panic. Verify fundamental safety steps initially.
Turn off the unit if you smell gas and call your gas company. Check circuit breakers and replace a tripped switch or blown fuse.
A safe secondary heat source and layering the clothes will help you wait for the pro. If your furnace goes out during a snowstorm, keep vents clear and watch carbon monoxide alarms to minimize danger until repairs are finished.
Immediate Safety
A nonworking furnace in a snowstorm creates immediate risks such as hypothermia, frozen pipes, and fire or gas hazards. Deal with these first before troubleshooting. The actions below indicate what to do, where to take action, and why it all matters.
1. Conserve Heat
Close doors and windows tightly to trap warmth. Stuff gaps with towels or draft stoppers. Hanging heavy blankets over doorways or windows provides insulation and reduces heat loss.
Get the family together in one warm room and keep the pets there as well. Clustering people together increases the effective temperature in the room and decreases the rate at which anyone can become chilled.
Wear layers. Base layers, sweaters, hats, puffer coats or ski pants, and wool socks help preserve core temperature. Take sleeping bags to bed with you at night for added insulation. They retain heat better than regular blankets.
If you use portable heaters, position them on a level surface a minimum of 1 meter away from anything flammable and never leave it unattended. Most importantly, vulnerable individuals, the elderly, infants, and those with chronic illness should be watched carefully for signs of hypothermia such as shivering, confusion, or slurred speech.
2. Check Vents
Check exterior vents and exhaust pipes for snow, ice, or drift accumulation that blocks airflow. Carefully shovel or sweep away snow or ice. Never jam hands or unprotected tools into vents.
Be on the lookout for leaves, litter, or branches that may have blown into the intake. Frost on your outside vent or unit can be a sign of extended defrost cycles or blocked flow. Clear around the unit and ensure the exhaust path is unobstructed.
Frozen, blocked vents can push combustion gases into the house and kill you.
3. Verify Power
Look at the breaker panel for tripped breakers or blown fuses connected to the furnace or HVAC. Make sure the furnace power switch is on and the thermostat is in ‘heat’ mode.
A blank display or low battery can be the culprit. Try nearby outlets or lamps to determine if there is a more extensive outage. If the power is out, think about safe alternative heat and carefully place generators so exhaust does not blow into living spaces.
4. Reset System
Turn the furnace off at the thermostat and at the breaker, wait a few minutes, then turn them both back on to try a reset.
Listen for the blower or ignition to come back on and monitor the thermostat for any error codes or blinking lights. If you hear any strange noises or experience repeated shutdowns, record them to report to a technician.
5. Assess Fuel
For propane or oil, check tank level and lines for freezing. Check pilot lights or ignitions on gas furnaces and drips or leaks along fuel lines.
If you smell gas, get out, open windows, and call emergency services right away.
Basic Troubleshooting
Begin by verifying the thermostat is in heat mode. If it’s on fan or off, the furnace will not run. Turn the mode to ‘heat’ and crank up the temperature a few degrees above the current room temperature to get the furnace to fire. If the screen is blank, check the batteries or power to the thermostat. A working thermostat is the easiest solution and can save you from having to troubleshoot the furnace unnecessarily.
Swap out a grimy air filter to enhance airflow and keep your furnace from overheating or shutting off. A clogged filter cuts off airflow, which trips safety switches and can cause the unit to cycle off. Just shut off the furnace, take out the old filter, note its size, and pop in a new one rated for your system.
In cold weather, check filters every 1 to 2 months. If you have pets or high dust, check sooner. Seasonal filter changes are basic troubleshooting that cuts down on mid-storm failures and keeps indoor air better.
Even if your heat is on, if snow and ice surrounds the outside unit, vents and intake pipes, it can suffocate the ventilation and heating system. Snow accumulation on vents or the combustion air intake can suffocate the furnace and cause it to shut down or run inefficiently.
If you can safely do so, use a broom or soft shovel to clean out any buildup within approximately 1 to 2 meters of the unit and clear any vent terminations on the building exterior. For clogged condensate lines or flues, carefully defrost with warm (not boiling) water or a hairdryer on low, being cautious of electrical components. Proper ventilation keeps you from suffering the dangerous backdraft of combustion gases and assists with the system’s re-ignition.
Be sure to hear if there is any banging or rattling, which could be a mechanical issue needing repair. Loose panels, dying blower motors, or combustion issues make specific noises. A steady hum or momentary ignition click is fine.
Loud bangs, grinding, or high-pitched squeals mean stop and never run the unit if safe operation is questionable. Observe the noise, location, and error codes on the furnace display. This provides a technician a diagnosis faster.
Time is of the essence. Avoid frozen pipes and hypothermia. Dress in layers, such as wool socks, puffer coats, and ski pants. Employ sleeping bags or hot water bottles as you work through solutions.
Use portable heaters only with strict safety measures. Keep clearances, use tip-over and overheat protection, and never run fuel heaters indoors without ventilation. If this initial step doesn’t restart your system, call an HVAC professional and ensure you have backup plans, such as a generator, to keep necessary systems like HVAC and communications running.
Temporary Solutions
When a furnace breaks in the middle of a snowstorm, the temporary steps minimize danger and keep everyone semi-cozy until you can schedule a fix. Begin with simple checks: verify the thermostat is set to “heat” mode and the power to the furnace is on. If those are right and the unit still won’t run, rush over to temporary heat, room isolation, and body warmth measures to avoid hypothermia and safeguard pipes.
Safe Alternatives
Stick to certified heat products. UL-listed electric space heaters and infrared units offer focused heat. Maintain a 0.9 metre (3 feet) distance from curtains, bedding, furniture and other combustibles and don’t ever leave them unattended.
Radiant heat packs and electric heated blankets are great in beds, but adhere to manufacturer instructions to prevent burns. Don’t fall asleep with it on high! A wood stove or indoor fireplace works well when your chimney is cleaned, your flue is open and your ventilation is good.
Don’t employ outdoor cooking equipment, such as charcoal grills or propane camp stoves, indoors. They put out carbon monoxide and are fire hazards. Tiny camping gas stoves are fine in a vented shelter outdoors, but not in living areas. Hot water bottles and sealed heat packs can be used to warm beds. Put them inside covers and layers and make sure that they aren’t leaking or too hot.
Room Isolation
Heat by shutting unused rooms. Shut doors to unused rooms and block door jamb gaps with towels or weatherstrip caulk. Hang thick blankets or plastic over indoor doorways and windows to block drafts and create a smaller heated area.
Select must-have rooms, usually a primary living room and several bedrooms, and transition humans and animals into the smallest and most insulated room in order to preserve warmth. If you can, lay out mattresses or sleeping bags. Sleeping bags beat normal sheets and quilts as they trap warm air right around your body.
Create a simple checklist: block drafts, close vents to unused rooms if safe, and concentrate occupants in one space.
Body Warmth
Layer clothing to trap body heat: base layers, sweaters, coats, hats, scarves, gloves, and fluffy socks. Get all of you wearing winter gloves and hats inside. A lot of heat is lost through the head and hands.
Make warmth by curling up under heavy blankets or sleeping bags. Humans together are far warmer than those alone. Move every once in a while with a little light exercise to get the blood moving and warm fluids such as tea, broth, or hot chocolate.
Boil water on a regular or safe camp stove for humid heat and top up hot water bottles for beds. If the furnace outage happens at night, have everyone sleep in one room to help keep warm and provide easy monitoring of comfort.
The Mental Game
If your furnace goes out in a snowstorm, the first fight is mental. Sound thinking speeds clear action. Keep the house quiet, save energy, and concentrate on security. Here are actionable steps to handle stress, make a plan, and keep everyone linked while you wade through troubleshooting and band-aids.
Stay Calm
Breathe deep and slow and talk in even tones to them. A calm voice numbs anxiety, which otherwise fogs your judgment and causes you to make unsafe decisions. Don’t use ovens, grills or portable generators inside. Rash efforts to generate heat can establish fire or carbon monoxide hazards.
Delegate simple tasks: one person checks vents and the thermostat, another gathers blankets and warm clothing, and a third watches children or pets. Small roles give people purpose and reduce panic. Maintain light humor when possible. A quick joke or a remembered moment can reduce stress hormones and help people deal with the frost.
Keep in mind that routine furnace tune-ups typically stave off these disasters, so use the outage as an opportunity to book servicing post-storm.
Make a Plan
Start with a short prioritized list: safety checks first, then basic troubleshooting, and finally temporary warming strategies. Safety walk-throughs include making sure that doors and windows close, looking for drafts, and ensuring smoke and CO detectors have power.
Troubleshooting steps are to check the thermostat batteries or settings, inspect the breaker panel, and confirm the pilot light or ignition sequence if your system has one. If the indoor temperature approaches life-threateningly low levels, get ready to move someplace warm, like a friend’s house or warming center.
Get everyone involved based on skill and age. Let the kids fold blankets, the adults brew hot drinks, and have someone keeping tabs on potential hypothermia. Check vulnerable individuals on a schedule, such as every few minutes. Regular, short checks mitigate danger and make you less anxious. Fast action minimizes the risk of frozen pipes and other damage that can occur in extended cold.
Communicate
Remember to keep phones charged and in a common location for emergency calls and repair updates. Post key information in view: emergency numbers, the troubleshooting checklist, and a note on when to leave if conditions worsen.
Make sure you communicate to everyone what is going on and what you are doing so there is no ambiguity. Contact neighbors to provide updates and resources. They might provide a space or assist if your condition worsens.
Consistent, transparent communication diminishes alienation, alleviates fear, and keeps the family united as you navigate this period of decision-making.
Professional Assistance
Call a licensed HVAC professional when these simple checks—thermostat, filters, breakers—don’t bring the heat back or anything looks dangerous. Professional repair minimizes the risk of additional damage and fixes threats that homeowners can overlook.
A pro can run diagnostics, replace worn parts, and verify it is up to safety standards. In stormy conditions, numerous providers have 24/7 emergency support available. With a pro on speed dial, you can avoid the dangers of prolonged cold exposure, frozen pipes, and other winter hazards.
When to Call
If you smell gas, hear carbon monoxide alarms going off, or sense a lingering rotten-egg scent around the furnace, flee and call emergency services before an HVAC pro. Continuous shutdowns after resets or repeated tripping of safety controls indicate more than a minor malfunction and require an expert evaluation.
Loud bangs, grinding, or rattling likely indicate loose parts, faltering motors, or heat exchanger problems that can be dangerous to your health. Do not operate the furnace until a technician examines it. A sudden inexplicable increase in energy consumption or frequent cycling indicates inefficiency or control faults.
A pro can measure its performance and suggest repairs or a replacement if necessary.
Finding Help
Seek out local HVAC providers that advertise 24/7 winter or emergency support. Those are the companies most inclined to answer during storms. Ask neighbors, building managers or friends for the names of repair crews who showed up on time and actually got the thing fixed in the cold.
Check recent online reviews, especially for winter response times and expertise with high-efficiency furnaces and sealed combustion systems. Keep contacts for trusted technicians in a visible location in your emergency kit, along with phone numbers, license or certification numbers, and any service contract information.
It is handy to have during a storm.
What to Ask
Inquire if your furnace model has any known cold-weather failure modes and which components to monitor. Ask for an ETA and what safety steps you should take in the meantime, like turning off your gas or airing out rooms.
Receive suggestions for secure interim heating and precautions against frozen plumbing, as an appliance technician can recommend electric heaters, venting or pipe insulation. See if the fix is covered by your warranty or service plan and if preventative maintenance might have prevented the failure.
Schedule follow-up maintenance to keep your system humming all winter.
Future Prevention
Future Prevention – Preventing future furnace failures requires a combination of regular maintenance, focused storm preparation and transparent family habits. The actions below outline what to do, why it’s important, where to focus and how to make each modification feasible and sustainable.
Regular Maintenance
Swap the air filter every month in the heating season to maintain steady airflow and prevent dirty-filter shutdowns. A plugged filter compels the blower to labor and can cause premature motor demise. For future prevention, have a professional inspect the heat exchanger, blower, ignition system, and gas lines every year before winter sets in.
This is your best bet to catch the cracks, corrosion, or wear that cause carbon monoxide leaks or ignition problems. For homes in extreme climates, think about biannual inspections in spring and fall to maintain the system at top performance through temperature swings. Tidy up around your furnace and maintain a minimum three-foot clearance from any flammable objects.
This reduces fire risk and facilitates techs’ component access. Test carbon monoxide detectors monthly and replace batteries as needed so you have early warning if the heat exchanger fails. Newer furnaces tend to run more reliably and consume less power. Consider replacing if repair frequency is increasing or efficiency has dropped.
Storm Preparation
Shovel snow and ice away from outdoor units, intake vents, and exhaust pipes both before and after a snowfall to avoid blockages that shut down the system or push toxic exhaust into the home. Put a little awning or barrier over outside vents to reduce direct snow accumulation, but nothing that impedes airflow.
If you have a propane, oil or wood stove, don’t forget to stock up on fuel before major storms so you have options when the furnace is out. Weatherstrip windows and doors and apply draft excluders to help maintain indoor temperature and ease the burden on your heating system.
Create a checklist of pre-storm tasks: check the thermostat, circuit breakers, and air filter; verify emergency heat sources; and confirm that the heating unit sits on a flat, level surface to avoid mechanical stress. Prevent future accidents by distributing heat-generating appliances across multiple outlets and never use an extension cord for high-draw devices.
Emergency Kit
Put together a kit of flashlights, extra batteries, blankets, a portable space heater with tip-over shut-off technology, and a first-aid kit. Add a printed list of vital numbers, including HVAC techs, utility companies, and emergency services, so contact info is accessible without power.
Bring additional winter coats, hats, gloves, and heavy socks and reserve nonperishable food and bottled water for a minimum of 72 hours. In the interest of future prevention, keep a mini tool kit and flashlight by your furnace so you can check breakers and reset switches safely before calling for service.
Conclusion
There’s an urgency to a cold house in the middle of a snowstorm. Think on your feet and stay cool. Check the power, thermostat, breaker, and filter. Use a space heater or warm blankets for short stretches. Keep vents clear and doors closed. Call a licensed HVAC tech if those fixes fail or if you smell gas. Coordinate by sharing your location and any symptoms so the technician can come prepared. Post-storm, schedule a full service and arrange a filter and maintenance plan. Easy fixes now reduce danger later.
If you like, I’ll put together a quick checklist you can print and tuck by your thermostat.
Frequently Asked Questions
What should I do first if my furnace stops working during a snowstorm?
Turn off the furnace and any gas valves if you smell gas. Be on alert for carbon monoxide alarms and get out if they go off. Keep your family safe and relocate to a warmer area or find temporary shelter if necessary.
How can I check the thermostat quickly and safely?
Double-check that the thermostat is on “heat” and has a temperature set higher than room temperature. Change batteries if the display is blank. These inspections are quick and can sometimes correct minor problems.
Can I safely try to restart the furnace on my own?
If there’s no gas smell or visible damage, reset the furnace with the power switch or breaker and the reset button on the unit. If you’re not certain, wait for a professional.
What temporary measures keep the house warm until help arrives?
Layer up with sweaters, hot blankets, and shut down unused rooms. Deploy a safe, vented space heater at a safe distance from combustibles. Stay hydrated and use warm drinks to help maintain body heat.
When should I call a professional HVAC technician?
Call a licensed technician if the furnace won’t restart, if you smell gas, see soot or leaking, or if the pilot won’t stay lit. These are all repair issues that deserve trained attention.
How can I avoid furnace failures during future snowstorms?
Have your furnace serviced annually, replace filters every one to three months, keep vents clear, and install CO and smoke detectors. Routine maintenance minimizes repair emergencies and increases safety.
Are portable heaters and generators safe to use indoors during a blackout?
Use electric space heaters indoors and adhere to manufacturer safety recommendations. Never bring fuel-powered generators or charcoal grills indoors because they produce fatal carbon monoxide.