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Heating System Repair: What to Do When the Heat Cuts Out

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Heating System Repair

What to Do When the Heat Cuts Out

Heating and cooling accounts for half of an average household’s energy use, which means if your annual household energy bill is $2,000, $1,000 of that went towards HVAC use. And if your HVAC system isn’t running efficiently, you could be paying even more. HVAC systems that aren’t maintained are also more likely to break down when you need it the most- meaning you could be left in the cold come winter. If this happens, you’ll be reaching for your phone for a local HVAC repair technician because while being cold is uncomfortable, it is also unhealthy.

There are some issues that can be remedied DIY, while others are best left to professionals. Discover what you can and should do in case your heater goes out in the dead of the winter below. 

What's that Smell?

Almost have of US households use natural gas as a source of energy. If your heater uses natural gas and it suddenly breaks down, keep your nose on alert for odors.

The smell of rotten eggs can indicate a gas leak. That sulfuric odor comes from mercaptan, a chemical that makes methane — the primary component of natural gas — easier to detect.

man covering nose

Note that residential natural gas contains between 85% to 95% methane. Methane is an odorless, colorless, flammable gas, and exposure to it can cause health issues like headaches, nausea, and suffocation.

So, if you smell sulfur/ rotten eggs after your heater dies, open your windows, then leave your home and call your natural gas provider to let them know about the potential leak.

If there are no unusual odors in your home, then it’s possible your thermostat is the culprit for your cold home. So before you call in the cavalry, try troubleshooting with these DIY remedies.

programmable thermostat

Check the Thermostat

An HVAC’s thermostat senses and controls temperature.  It instructs the HVAC unit as to whether it should provide heated or cooled air based on the temperature it’s set to. Once the household temperature has hit the desired setting, the thermostat tells the unit to stop heating or cooling.

Because the thermostat basically tells your system what to do and when, it’s understandable why most signs of HVAC problems have you checking for a faulty thermostat. So inspect the thermostat first, since the lack of heat may due to dead batteries or that another resident accidentally switched the setting to “Auto” or “Cool.”

Change out the batteries and set the thermostat to “Heat.” Wait for a few minutes to see if your heater kicks on and begin heating your home.

Check the Circuit Breaker

If the thermostat appears to be off, at default settings or just not displaying accurate information, it may have shut down due to a trip in your home’s main circuit breaker. A power outage may have triggered the breaker to automatically shut off to prevent potential electricity overloading. If an overload did occur, just switch the breaker for your HVAC unit back to “ON.” This should restore power to the thermostat.

breaker box
air filter

Check that the Filter is Clean

Your heater may not be warming your home enough because of restricted airflow. A likely culprit is a dirty filter. The heated air won’t exit the vents or ducts if there’s a lot of dirt and debris trapped in the filter.

Hopefully, your heater’s filter is washable, as this means you only have to clean it to reuse it. If not, then you need to purchase a replacement filter.

When to Call For Help

If these troubleshooting steps don’t work, it’s time to call for help. Your heater may have failed (and needs repair) due to any of the following reasons:

Faulty Thermostat

A dying thermostat will continue glitching until it finally dies. “Glitches” include frequent temperature misreading, which causes inefficient heating. A faulty thermostat may also cause your HVAC unit to short-cycle.

If changing out the batteries doesn’t fix the thermostat, there may be a blown fuse or loose connections or parts in the unit. If so, repairs or replacement parts will be needed before it will run again.

Failed Fan

HVAC fans are designed to blow out and circulate heated (or cooled) air. If the fan becomes damaged or loosens, it won’t properly push air out of the vents or ducts. The build up of dirt and debris on fan blades can also lead to inadequate heating.

Damaged Blower Motor

The fan won’t work if the blower motor isn’t supplying power to it. So, if your heater’s motor dies, the fan won’t rotate and no heated air will come out of the unit. 

Blower motors often fail due to corrosion, which is caused by poor venting and ductwork. Condensation- common in air conditioners- can also spread to your heater. When moisture enters the heater, oxidation can occur within the motor.

Shot bearings or an overloaded/tripped circuit breaker can also cause motor failure.

Broken Belt

Some HVAC units have a belt-driven motor that transfers rotational energy to the fan. This energy then powers the fan to blow out heated or cooled air. But for the belt to transfer enough energy to the motor, it needs to have proper tension.

HVAC belts can loosen over time from age, wear or dirt build-up. Incorrect tension can overstress the belt and hasten its degradation and ultimate demise.

A broken belt requires replacement ASAP because without it, your HVAC unit’s motor won’t be able to move the fan to circulate heated air.

If you smell burning rubber, turn off your HVAC unit and call an HVAC repair specialist right away. This smell is likely from an overstressed or broken belt. The friction can damage not only the belt but also other key parts like the motor and fan.

Cracked Heat Exchanger

A heat exchanger is designed to heat the air in a furnace (or water in a boiler). It does so by burning natural gas, liquefied petroleum gas (LPG), and other heating oils. As the heat exchanger burns these energy sources, it generates combustion gases, which it traps inside the unit to prevent gas leaks. These gases include carbon dioxide (CO2), carbon monoxide (CO), and nitrous oxide (NO).

Because the exchanger contains metal components that expand and contract with heat, over the years, these metals will degrade, creating stress cracks and other damage in the exchanger. When this happens, all those combustion gases can leak and contaminate the air in your home.

These gases are harmful and potentially lethal. Carbon Monoxide poisoning alone lands approximately 50,000 people in emergency rooms every year and claims at least 430 lives annually.

If your heater suddenly dies and your house smells like anything out of the ordinary- especially the smell of rot, decay or death- leave right away. A formaldehyde-like smell is a solid indicator that you have a cracked heat exchanger. Contact your local HVAC technician for immediate heating repairs.

As an added precaution, consider installing carbon monoxide detectors at home. These devices have sensors that trigger an alarm when elevated levels of carbon monoxide are in the air. Some CO detectors are also combined with smoke sensors and alarms. These are multi-sensor devices that will notify you of possible fires or gas leaks.

Get Professional Heating Repair

If your heater breaks down during the day, schedule a same-day HVAC repair appointment. This way, you can have your heater up and running before the sun goes down. This is especially important if you don’t have a space heater or fireplace to serve as alternative heating.

If the malfunction happens late at night or the early morning, opt for emergency HVAC repair. Without the sun for heat, you and your loved ones are at a higher risk of hypothermia.

Although hyperthermia (heat stroke) in summer is also dangerous, hypothermia claims more lives. In fact, between 2003 and 2013, there were 13,400 hypothermia deaths in the US.

Don’t risk your health and the safety of your loved ones over of a failed heater. Emergency heating repair may cost a bit more than normal services, but it’s worth it.

Stay Warm While Waiting for the HVAC Technician

After scheduling HVAC repair, layer up in sweaters and blankets. Then if you have a fireplace or electric blanket, it’s time to fire them up.

Close all curtains and blinds and place rolled up towels or bunched up pillows by the cracks under your doors to prevent cold air from entering your home.

Gather your family members in one area to help everyone stay warm even as your bodies lose heat. A good gathering spot is the kitchen so you can cook something. This will not only generate heat from the oven or stove, but eating and drinking something hot will warm you and trigger digestion, which generates internal heat. The heat from a mug will also warm up your freezing hands.


woman bundled up in blanket

An Ounce of Prevention is Worth a Pound of Cure

Get Furnace Maintenance to Keep Your Heater from Breaking Down

HVAC preventative maintenance extends the lifespan of your HVAC system by preventing parts from breaking down and helps keep your heater and cooler efficient. Efficient heating and cooling system can help you enjoy 10% to 40% in energy savings.

Some DIY HVAC maintenance tasks you can do to prevent early breakdowns include:

Keep Your Air Filter Clean

Filthy filters restrict airflow that can cause the unit to overheat. Besides, letting the filter clog up with debris can cause poor indoor air quality. A new (or clean) air filter can reduce your home’s energy consumption by up to 15%

Inspect your filter monthly to determine if replacement is needed. Most filters are effective for up to three months, but if you have pets or live near a construction site or busy road, you may need to replace them more often.

Keep Obstructions Away from the Indoor and Outdoor Units

The indoor and outdoor units of your HVAC system should be free of any blockage. For the indoor unit, there should be at least two feet of clearance. Make sure no objects (like furniture) block the indoor unit.

The outdoor unit is more prone to blockages like tall grass, leaves, and other debris. As part of your HVAC maintenance, keep the grass mown and remove any debris from the outdoor unit.

Stop Suffering: Get Your Heater Repaired Now

If our troubleshooting tricks didn’t help, then contact us and our technician will repair your unit right away.

If your heater conks out in the middle of the night, you don’t have to wait until the next day to get it fixed. Here at Phoenix Air ATX our HVAC technicians are available 24/7/365 for emergency heating repair.

Peace of Mind for $179 a year

Join our Maintenance Plan Program and get all the perks of membership: 10% discount on repairs, seasonal tune-ups, priority scheduling and more. 100% satisfaction guaranteed.