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Broken Furnace

Why Did My Furnace Stop Working?

January 12, 2022

In most cases, your Pittsburgh home will stay warm throughout the winter without issue. Sometimes, however, your furnace could stop working for several reasons. At Jacob Heating & Cooling, we’ve put together some of the most common furnace issues and what you can do to get your furnace back up and running.

What are Some Common Furnace Issues?

The gas line is closed.

If the gas line is closed, then the furnace isn’t receiving any fuel and will not be able to generate heat. Be sure to check that the gas valve on the line is open.

You have a cracked heat exchanger.

Your heat exchanger transfers the heat from combustion to the air, but over time, cracks and other damage can cause the furnace to consume more and more energy. When the heat exchanger is cracked, the combustion fume accumulates and can lead to dangerous carbon monoxide leaks. Signs that the heat exchanger is cracked include:

  • You experience an unpleasant odor when your furnace is running.
  • Your home’s surfaces appear to be dirtier. This is caused by the release of soot into the air caused by your furnace’s inefficient burning.

This is extremely dangerous, so it is important that you have an HVAC technician with Jacob Heating & Cooling immediately come out to check to see if the heat exchanger is what is causing your furnace issues.

Your air filter is clogged.

If your air filter is clogged, then the airflow through your furnace is restricted, which can lead to overheating. This can also lead to the safety switch shutting off the unit when it reaches a higher temperature.

If your furnace is malfunctioning, check the air filter. Replace the filter if it is dirty and covered in debris. After replacing, give the unit time to cool down and then restart the furnace.

The thermostat is malfunctioning.

Check to make sure your thermostat is working properly by checking that it is set to heat and set at least five degrees higher than your current room temperature. If that doesn’t work, replace the batteries in your thermostat.

In some cases, electromechanical thermostats require dusting on the inside, which can be done with a soft paintbrush. You also want to look at where your thermostat is located to ensure that it isn’t receiving a false reading from the sunlight, space heaters, ovens, lamps, or other sources of heat.

The circuit breaker flipped, or the furnace switch was shut off.

Look at the switch near the furnace and make sure it wasn’t accidentally switched off. If it was switched off, flip it back on and see if that resolves the issue. If not, you will have to check the circuit breaker.

Check that the power is turned on for the breaker box or fuse box.

Check the labels on the breaker box to see if the HVAC breaker is on. If it is off, switch it back on. If your breaker box isn’t labeled, look for the switch that is facing the opposite direction of the rest of the switches.

To reset the breaker, be sure to flip the switch off until you hear a click and then flip it back on. If you have a fuse box, look for any melted or discolored fuses. Unscrew and replace the fuse with the same exact type and size.

After you’ve tried one of these methods, switch the furnace on and see if it is working. If it is not, and the breaker is still tripping, or the power is still out, you will need to contact a professional for assistance.

Furnace airflow is blocked.

Airflow can become blocked by a clogged air filter, but it can also be blocked by rugs, furniture, or items stored around the furnace, which can lead to overheating and cause the unit to shut off.
After checking the air filter, you also want to make sure the items around the furnace are moved away. It is recommended that you keep at least a 6-foot clearance. You will also want to check that all your vents are open and unblocked to allow air to flow.

The burners are dirty.

Throughout the lifespan of your furnace, the burners will collect rust and dirt that can reduce your heat output. Check your burners for dirt and rust. If they need to be cleaned, you can complete the cleaning by:

  • Shut off the electricity for the furnace at the breaker box and close the gas valve.
  • Remove the access panel to the furnace, which will lead to the combustion chamber. You may also need to remove a small access panel that encloses the burner chamber.
  • You will see a metal clip that must be removed to detach the burners.
  • Using a soft brush and a vacuum, carefully clean the debris off the burners.
  • You can also blow compressed air through the burners to remove any debris that has accumulated inside. Tapping and turning the burner can also help remove debris.
  • Put the burners back and attach the clips to secure them.
  • You can then replace the access panels and restore the power and gas to the furnace.

Still Having Furnace Issues? Call Jacob Heating & Cooling!

The furnace issues mentioned above are just a few of several issues that can occur with your furnace and cause you to lose heat. We recommend calling our team of professionals to resolve any furnace issues you may be having. Our experienced team has the knowledge, tools, and quality replacement parts to get the job done right. Contact us today to learn more!

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