Your Furnace Died: Emergency HVAC Guide for Westchester Homeowners

Before you call an HVAC company and pay $140 to $600 for an emergency service call, spend 10 minutes checking the obvious things. About half the furnace "emergencies" that techs respond to are fixed by one of these steps.

1. Check the thermostat. Make sure it is set to HEAT and the target temperature is above the current room temperature. If it is a digital thermostat, replace the batteries. Dead thermostat batteries are one of the most common false alarms.

2. Check the circuit breaker. Gas furnaces need electricity to run the blower, igniter, and control board. Find the breaker labeled "furnace" or "HVAC" in your panel and flip it fully off, then back on. Also check for a switch on or near the furnace itself. It looks like a regular light switch and sometimes gets bumped off accidentally.

3. Check the filter. Pull the filter out. If it is solid gray or black, the furnace may have shut down because of restricted airflow. Replace it with any filter from the hardware store that fits, or run the system briefly without a filter to see if it fires up. (Do not run it without a filter long-term.)

4. Check the pilot light or igniter. Older furnaces have a standing pilot light. If it is out, relight it following the instructions on the furnace panel. Modern furnaces use electronic ignition, which you cannot reset manually. If you hear clicking but no ignition, the igniter may have failed.

5. Check the gas valve. The gas shutoff on the supply line to your furnace should be parallel to the pipe (open position). If it is perpendicular, someone turned it off.

This is the part people forget. Your furnace is out, the house is getting cold, and your biggest financial risk is not the HVAC repair. It is a burst pipe.

A well-insulated Westchester home holds heat for 8 to 12 hours after the furnace stops. A drafty older house drops faster. If it is 15 degrees outside and your furnace dies at midnight, you have until morning before pipes in exterior walls become a serious concern.

Open the cabinet doors under every sink on an exterior wall. This lets room air circulate around the pipes. Turn on a thin stream of water at the faucet farthest from where the water enters your house. Even a slow trickle keeps water moving through the pipes, which resists freezing.

If you have pipes in an unheated crawl space or garage, point a space heater at them. A $30 space heater protecting exposed pipes is a much better investment than the $1,000 to $4,000 burst pipe repair bill.

If the house is going to be below 45 degrees for more than 24 hours and you cannot get the heat fixed, consider draining the water system. Shut off the main water valve, then open all faucets (hot and cold) starting at the top floor and working down. Flush all toilets. This removes most of the water from the pipes so there is nothing to freeze. A plumber can help you do this if you are not comfortable with the process.

Space heaters are the most practical emergency heat source. Ceramic heaters with tip-over protection and overheat shutoff are the safest option. Keep the heater at least 3 feet from anything flammable. Plug it directly into a wall outlet, not an extension cord. Extension cords overheat under the sustained load of a space heater and cause fires. Space heaters cause an average of 1,600 house fires and 70 deaths per year in the US. Every one of those fires was preventable.

If you have a fireplace, use it. Open the damper before lighting anything. Use a screen. Never burn treated wood, cardboard, or trash.

Close off rooms you are not using. Hang blankets over doorways to shrink the heated space. Gather the family in one or two rooms. Body heat from four people in a closed room raises the temperature noticeably.

Cover windows with blankets or plastic sheeting. Windows are where 25 to 30% of your heat escapes. Even a bedsheet taped over a window helps.

Electric blankets are safe and efficient for sleeping. Rated sleeping bags work too. Layer up.

Do not use your gas oven or stovetop for heat. This produces carbon monoxide, which is undetectable without a CO detector and kills 400 Americans per year. An electric oven with the door open is acceptable in a true emergency but is not efficient.

A furnace failure can involve carbon monoxide, and CO is impossible to detect without a working detector. It has no smell, no color, no taste. Symptoms mimic the flu: headache, dizziness, nausea, confusion, fatigue.

Carbon monoxide kills about 400 Americans every year and sends more than 100,000 to the emergency room. Between 2005 and 2017, furnaces were involved in 900 CO deaths nationwide according to the Consumer Product Safety Commission. Peak season is November through February, which is exactly when your furnace is running hardest.

A cracked heat exchanger is the most common source of furnace-related CO. The heat exchanger separates the combustion gases from the air your furnace blows into the house. When it cracks, CO mixes with your heated air. You cannot see the crack without specialized tools.

New York's Amanda's Law requires working CO detectors in every home with a fuel-burning appliance or attached garage. Detectors must be within 15 feet of each sleeping room. If you do not have one, install one today. They cost $20 to $40 and take five minutes to mount.

If your CO detector goes off, or if everyone in the house has unexplained headache and nausea symptoms, get out of the house and call 911 from outside. Do not re-enter until emergency responders clear the building.

Most furnace failures announce themselves weeks or months in advance. These are the warning signs to watch for so next year does not end with another 2am emergency.

A gas furnace lasts 15 to 20 years. Oil furnaces last 15 to 25. If yours is in that range, start planning for replacement before it fails on the coldest night of the year.

Rising gas or oil bills without a change in usage means the system is losing efficiency. A furnace that ran at 80% efficiency when new might be operating at 60 to 65% after 18 years. That gap shows up in every monthly bill.

Short cycling (the furnace turns on and off frequently without reaching the set temperature) indicates an overheating issue, a bad flame sensor, or a thermostat problem. This stresses every component and accelerates failure.

Strange noises matter. Banging on startup can mean a delayed ignition, which is a minor issue caught early and a cracked heat exchanger if ignored. Squealing suggests a failing blower motor bearing.

A yellow or orange pilot light (should be blue) means incomplete combustion. This is a carbon monoxide risk and requires immediate service.

The 50% rule: if a repair costs more than half of what a new furnace costs, replace it. A new gas furnace averages about $5,500 installed in Westchester. If a repair quote comes in at $2,800, spend the extra $2,700 and get 15 to 20 years of reliable heat instead of patching a dying system.

Schedule a furnace tune-up in October, before heating season starts. A standard tune-up costs $80 to $200 and includes cleaning the burners, testing the igniter, checking the heat exchanger, inspecting the flue, and verifying safety controls. The techs who do this work say the same thing: the furnaces that break in January are the ones that never got serviced in October.

Replace your air filter every 1 to 3 months during heating season. A clogged filter makes the system work harder, overheats the heat exchanger, and shortens the furnace's life. Filters cost $5 to $30.

Test your CO detectors monthly. Press the test button. Replace the batteries once a year. Replace the detector itself every 5 to 7 years (the sensor degrades).

Know your utility's emergency number before you need it. Con Edison (southern Westchester): 1-800-752-6633. NYSEG (northern Westchester): 1-800-572-1121.

Many HVAC companies offer maintenance plans for $150 to $300 per year that include an annual tune-up, priority scheduling for emergencies, and reduced emergency rates. If your furnace is older than 10 years, the priority scheduling alone could be worth it on the night your heat goes out.