How To Fix and Repair The Most Common Furnace Problems

Neighborhood Plumbing, Heating, Cooling & Electrical technician helping homeowner fix problems with her furnace.

If your furnace doesn’t work like it should, you may be searching the web for a heating technician that can help.

However, did you know that some of the most common furnace problems might be able to be solved right at home by none other than you? Yes! If your furnace isn’t working properly, you might be able to fix a furnace on your own with some residential gas furnace troubleshooting tips from the pros. Here are a couple of things to keep in mind before you start any furnace repair.

  1. Find your furnace’s owner’s manual. This manual will have the most specific information for your exact unit and can tell you which furnace parts you will need.
  2. If you can’t find your manual, you may be able to find information on the internet by using your furnace’s model number, serial number, and manufacture date. Look for these numbers on your furnace’s manufacturer’s label. Write them down and have them handy.
  3. Also, when dealing with electrical devices, you want to make sure that the power is disconnected and off before you interact with it. Safety first!

Faulty Pilot Lights

Does your pilot light keep going out? That could be a couple of problems. 

One, you may have a faulty or loose thermocouple. Check and tighten if needed. 

Two, your pilot orifice could be clogged. Try to clear the clog with a piece of wire. REMEMBER: Shut off the gas and shut off the switch or circuit breaker before you start.  

Three, the setting may be too low for your pilot’s flame. Generally, the flame adjustment is simply a screw. Turn the screw to get the proper size flame which is about 1.5 to 2 inches of flame with no yellow.

 Consult your furnace’s owner’s manual for precise instructions. 

No Heat Troubleshooting

If you’re not getting any heat, some things you could try are:

  • Verify your thermostat setting is on “heat.”
  • Check to see if the fuse or breaker that is powering your thermostat is not blown or is on. If it is not on, turn it on. If the furnace fuse is blown, replace it.
  • Make sure the furnace has power. There might be a switch. Flip it to the on position.
  • Reset the motor, as it may have overloaded. There should be a reset button. Press it once. If nothing happens, try again in 30 minutes.
  • Check your pilot light and gas valve. Relight your pilot light if it has gone out. Turn the gas valve to the on position.

Broken Fans

Make sure your fan is, in fact, broken. On your thermostat, turn your heat off. Then, turn to the “fan only” or “auto” position. If the fans still don’t turn on, you might have broken fans. 

Check the circuit breaker to see if it has tripped. If that is still not the problem, your broken fan will likely need to be replaced. Issues like these can be spotted early and before a major problem occurs with regular furnace maintenance. Heating tune-ups help catch and fix problems to prevent costly repairs.

Defective Blowers

Next, when troubleshooting your gas furnace, turn your attention to the furnace’s blower. Problems with your furnace blower include your system not blowing air. This issue could be occurring because the blower is clogged or blocked by debris.

Make sure that your furnace door is completely closed. If it’s open, the furnace will not work properly.

If you want to check the blower’s belt, first turn off the furnace breaker. If the belt is cracked, frayed, or broken, it will need to be replaced. Consult your furnace’s owner’s manual for the specifications of which belt you need, then simply replace it. 

BE CAREFUL! Blower motors can be hot!! If the motor is very hot, you might have had an overload. 

An overloaded blower motor generally needs to be replaced. It’s never a bad idea to contact a St. Cloud heating and air specialist who knows how to fix a furnace safely and efficiently.

Bad Electrical Connections

If your furnace doesn’t seem to have power, check your breaker box. Look for either a blown furnace fuse or a tripped breaker. Replace the blown fuse or turn the tripped breaker off and then back on.  If neither of these tips works, then you have faulty electrical connections and need a technician service.

Dirty or Clogged Air Filter

Whenever gas furnace troubleshooting, always keep your system’s air filter in mind. Countless furnace issues can occur because of a dirty or clogged air filter, including your system short cycling or over cycling. Fortunately, air filters can be found at your local home improvement store.

If your air filter is dirty or clogged, simply replace it. If you don’t know what kind to buy, just look at the one in your furnace. You can even take a picture of it on your phone. Bring it to the store and a store worker may help you locate the proper filter. 

Most filters have arrows on them showing which direction air must flow through them. The arrow should be facing the ductwork of your furnace.

It’s best to change the filter every three months. This HVAC furnace part may need to be replaced more frequently, depending on the time of year. The more you use your furnace, the dirtier the air filter will become. If you neglect your air filter, you may find yourself Googling “how to fix a furnace” once again.

Thermostat Malfunctions

Check the thermostat when gas furnace troubleshooting. If you find yourself trying to figure out how to fix a gas furnace, it might be easy to overlook the thermostat—but you certainly shouldn’t.

If your thermostat isn’t working correctly, here are a few tips that could get it back up quickly. 

Turn the power off and remove the cover. Clean it with a vacuum or a soft brush. Check it for any sign of corrosion, and then remove it with an electronic contact cleaner. Change the battery if that seems to be a problem.

Airflow Problems

Airflow problems generally mean something is stopping the air from flowing. Check your furnace filter. It may be dirty or even installed incorrectly. Replace it in the correct position. 

Another thing to try is to check all your vents. Make sure they are open. Too many closed vents can cause your furnace unnecessary heat buildup. 

Finally, if those don’t work, try hitting the reset button. If it doesn’t get better, try again after 30 minutes.

Loud Furnaces Noises

Is your furnace making strangely loud noises? If so, you may be wondering what you can do to fix a furnace and stop these sounds once and for all. When gas furnace troubleshooting, look out for these sounds and their causes:

  • Popping or Pinging: This could just be your ductwork expanding and contracting as your furnace heats your home.
  • Rattling: There may be loose furnace panels that need tightening.
  • Grinding: The furnace’s bearings need to be replaced by a professional.
  • Squealing: A belt may have slipped or needs replacing.

Problem Still Isn’t Fixed

It feels good to be capable and fix things on our own. But sometimes – especially if we don’t know what we’re doing – we can cause more damage than is initially present. That additional damage can cost substantially more than the original dilemma as well.

If you’ve been gas furnace troubleshooting and find yourself at a dead-end, contact professionals that know how to fix a furnace, like the ones at Neighborhood, for dependable St. Cloud heating repairs

Contact a Heating Expert

Folks, if you are unsure about how to fix a furnace, we would like the opportunity to help you out. Our certified heating technicians are experienced and work with these common problems often. We can keep both you and your home safe by making knowledge and experience-based repairs. 

We can save you the time it takes to figure out what your problem is, the time it takes to research how to fix it, and the time of actually gathering all the proper tools and fixing it. We want to take the stress of furnace repairs from you, and we want to get your furnaces working again as quickly as possible.

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