19 Common Furnace Problems (And How to Fix Them)

A furnace is a big investment. When all goes well, it runs continuously for years, providing heat and comfort with very little attention needed on the part of the homeowner except to service it regularly.

19 Common Furnace Problems

Unfortunately, that’s seldom what actually happens. Furnaces are machines made of many parts that must all work together correctly in order to run smoothly. Sometimes they break down and need to be repaired. 

It’s not always obvious that you have a problem with your furnace. But if you do spot a problem, you may be able to do something about it. Here are 19 Common Furnace Problems (And How to Fix Them).

Before we move on, if you are not comfortable with any of these DIY steps, then make a service call to Baylor Heating, Air Conditioning And Plumbing. You shouldn’t try to save a few dollars at the expense of your well-being.

1. Check Your Thermostat to make sure it’s ON 

Step 1: Some thermostats are connected to the house’s electrical system, while others use batteries. If your thermostat uses a battery, check it. Make sure it’s the right type of battery and that it is installed correctly. You may need to change the battery.

Step 2: Open the thermostat and carefully blow any dust that may have clogged it.

Step 3: Ensure that the date and time are correct on electronic or programmable models since the system may be on a timer.

Step 4: Now, check the breaker. If it’s on, turn it off and check the fuse for the furnace.

2. Safety Switch on Furnace Door  

This is a safety switch. In case the door is open while the furnace is running, the switch will shut off the power to prevent a fire from breaking out. Inspect for obstructions around the door and remove any that may be causing this problem. Make sure that nothing blocks the closed position of the door when it shuts.

If you discover you need to install a new safety switch, follow these steps;

Step 1: Turn off the power

Step 2: Prep the blower door

Step 3: Wire the safety switch

Step 4: Now, check and test the installation

3. Furnace is Not Producing Heat 

Try to Reset Home Circuit Breaker  

Step 1: If the furnace isn’t producing heat, then try resetting the home circuit breaker. This can be done by pressing a special button inside a panel of electrical breakers or switches. 

Here’s how to Test your Home Breakers: Go to your home’s breaker panel and look for the circuit that controls the furnace. Check to see if it’s thrown to the “Off” position or in the middle. 

Step 1. Manually test your breaker. Flip it back and forth.

Step 2. Make sure it is staying in the “On” position.

This will reset your breaker. If this does not work, you have a problem either with the wiring in the circuit or your circuit breaker itself.

4. Furnace is Not Producing Enough Heat 

Check and Change Your Clogged Filter   

A clog in the furnace filter can cause many problems, including problems with heating. This is because an air filter limits the amount of air that gets to the burner. This makes your furnace work harder to produce heat. Replacing your furnace filter is easy and helps to protect your HVAC components. It also improves your indoor air quality. 

5. Keep the Area Around Your Furnace Clean and Unobstructed 

It’s important to keep the area around your furnace clean and unobstructed. If you have areas filled with boxes or storage, make sure to sort through them. Get rid of anything that is blocking your furnace.

6. Heating or Rapid Cycling Problems  

If the furnace is cycling on and off rapidly or not producing heat, then you have a problem. This can be caused by several things, including clogged filters, dirty burners, faulty limit controls, bad inducer blower motor, or defective fan speed control board assembly. If you change the filter and the problem remains, you may have to call a professional.

7. Noisy Furnace or Duct Work 

Step 1: If you hear noises coming from your furnace, the problem could be a loose part. If it’s ductwork, then duct tape can fix this. If not, you should have it fixed by a professional from Baylor HVAC.

Common Furnace Noises

a. Pinging or popping sounds: This is a common noise, and it usually isn’t a problem. However, if the furnace is making popping sounds every time your blower comes on, then you have a more serious issue. This could be caused by dirt or debris in the burners, as well as corrosion.

b. Rattling noises: This is a sign that something isn’t screwed in or tightened enough. This could be a loose part that needs to be fixed by a professional.

c. Squealing noises: This means that something is rubbing against something else. It could be a loose belt, or it could mean that there is too much tension on the belt.

d. Grinding sounds: This usually means that your blower wheel is damaged or has broken parts in it. You will have to replace this part as soon as possible to prevent further issues.

8. Flame Sensor Needs Cleaning   

If everything seems to be working, but the furnace isn’t producing heat, then you might have a dirty flame sensor. You can clean it by taking off the front of your furnace and cleaning the electrode with some steel wool.

9. Know the Age of Your Furnace  

If you don’t know the age of your furnace, then now might be a good time to do some research. If it’s more than 15 years old, now may be a good time to think about an upgrade. With newer furnaces, you have access to technology that saves energy and improves indoor air quality.

10. Furnace Does Not Blow Air  

Step 1: If your furnace is blowing mainly cold air, then you have a problem. This may be due to dirty burners, clogged filters, faulty limit controls, or an inducer motor that is not working properly. If the filter is clean and the problem remains, then it’s likely that there’s a blockage in the ducts or a problem with the blower.

Step 2: The limit control can be tested for continuity using a multimeter. If you have an inducer motor that is not working, you’ll have to call a professional to come to service it.

11. Check Your Vents 

Do they need to be cleaned? If so, do so. Look for signs of clogs or blockages in the vents.

12. Inspect Gas Line 

If you have gas appliances, then inspect the gas line to make sure that it’s not leaking. It’s also possible that there is a blockage in the gas line or a defective regulator. Check your entire gas line. Is it closed? Is the switch turned off?

13. Smelling Gas 

Any type of gas leak can be dangerous. If you suspect a gas leak, it is important to leave your home and call a professional immediately. 

14. Check Your Limit Switch   

Step 1: If your furnace doesn’t have a limit switch, then you can skip this step. If you do have one, then check to make sure that it is working properly. Inspect the wires and connections for corrosion or damage. 

Step 2: Check for loose or broken wires on the temperature limiter (limit switch), then tighten the wires.

Step 3: If you find a loose wire, re-attach it to the furnace and make sure that it is making good contact with the screw terminal by clamping down on it or screwing it in tightly. Check for corrosion on the terminals and clean them if needed.

15. Check Your Electric Ignition or Pilot Control  

Step 1: If your furnace ignites but doesn’t stay lit, then you have a problem with the pilot. If there is no spark near the pilot to light it up, then you have an ignition system failure. Here are some ways to test the different components of the electric ignition system.

Step 2: Disconnect power from your furnace and check the wire connections at the safety limit control board and switch terminals. Check wiring and connection to the furnace. Make sure it is connected properly and isn’t corroded or frayed.

Step 3: Check for loose screws at the motor blower housing assembly repair kit. Tighten any loose screws if needed.

Step 4: Replace the limit switch if the other components are tested to be ok.

16. Oil the Furnace Blower Once a Year 

This helps the blower work more efficiently, saving you energy and money. It also helps to extend the life of your HVAC components. The blower distributes heat throughout your house.

17. Look at the Burner Flames  

Make sure that the gas flames are blue and don’t have any yellow or orange hue. If you see more of a yellow color, then your burners may be dirty. Turn the power and gas off and clean the burners with a vacuum cleaner.

18. Gas Furnace Blower Runs Continuously  

If your furnace blower runs continuously then you probably have a problem with the limit control. This will not cause a loss of heat in your home, but it can damage the unit if left on for several hours or longer. Turn off power and gas to the furnace and clean the switch using an electrical contact spray cleaner. 

19. Clean Leaves and Debris from Heat Pumps or Intake and Exhaust Vents  

Remove leaves, pine needles, and other debris that may be obstructing your unit’s venting system. Inspect and clear away debris around your heat pump.

Contact Us For More Details on The 19 Common Furnace Problems (And How to Fix Them)

There are many problems that can arise with your furnace. Today, we’ve discussed 19 of the commonest furnace problems and how to fix them. Get the most out of your system with preventative maintenance.

We’re here to help you with any heating repair. Whether it’s during regular business hours or after hours for emergency heating repairs, we’ll be there quickly to solve your problem. Our technicians are experienced, well-trained, certified professionals who’ll make sure you receive the highest quality care available. Contact us today at 812.425.8435.

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