10 Common HVAC Problems (And How To Fix Them)
Dealing with HVAC problems is an unfortunate part of being a homeowner. Without much HVAC knowledge, these problems can seem like the end of the world, even though they typically aren’t. That's why it’s important to have a basic understanding of common HVAC problems and how to fix them.
Common HVAC problems like poor airflow and musty odors in many cases can easily be fixed by replacing the air filter. Other problems, like temperature inconsistencies, can indicate problems with the air handler and ductwork. Keep in mind that it’s better to replace your AC or furnace if it’s over 15 years old, as repairs aren’t always worthwhile.
While you can fix some problems yourself, some repairs, like rewiring a thermostat, can be challenging. In that case, you’re better off calling a professional HVAC technician. Follow along as we highlight 10 common HVAC problems and suggest how to fix them.
10 Common HVAC Issues And Solutions
1. Short-Cycling
Short-cycling is one of the most common and annoying HVAC problems. This refers to an AC or furnace that turns on, runs briefly, shuts off, then repeats the cycle over and over. Unfortunately, this annoying cycle may happen indefinitely until you address the root of the problem.
This can occur due to dirty filters, low thermostat batteries, dirty evaporator coils, electrical issues, and more. The good news is that many of these problems are easily fixable without professional help. That’s why it’s a good idea to start by checking your air filter and thermostat batteries.
Slowly move through the list of possible causes until you reach something that you can’t fix, like a refrigerant leak. In that case, call your local HVAC service to fix the problem.
2. AC Blowing Warm Air
Nobody expects warm air to come out of their vents when they run the AC. However, this happens all the time, especially if you don’t keep up with HVAC maintenance. This can happen if your AC is low on refrigerant or if the condenser coils are dirty.
However, you should inspect the air filter before checking for those issues, as they require professional help. A clogged air filter can restrict airflow and strain your AC to the point where it blows warm air. Replacing your air filter should fix this issue, as well as many other common HVAC issues.
If you find ice on your refrigerant lines, it likely means that you’re low on refrigerant. This can occur naturally, but it can also happen if there’s a leak, which is dangerous. Schedule a checkup right away if you notice a leak.
3. Musty Odors
Do you notice musty odors when your AC or furnace runs? If so, it’s most likely because of excessive dust, debris, pet hair, and moisture in your air ducts. This can also happen if mold and mildew have formed in your ductwork.
Musty odors typically indicate that you haven’t had your air ducts cleaned in a long time. You’re supposed to get your air ducts cleaned every 3 to 5 years. Dust and debris accumulate within air ducts every day, and they can create blockages.
This debris can get moist when cold and warm air mix as you run your HVAC system. Schedule a cleaning to remove the debris and treat your air ducts for mold. Not only will your air ducts smell better, but you’ll also improve the indoor air quality.
4. Boiler Leaks
Nobody expects to see water pooling in front of and around their boiler. That means you may have to fix your boiler and pay for the cost of water damage. Leaks aren’t always easily detectable, as water may seep from the joints and pressure relief valve.
Boilers are also often tucked away in areas where homeowners don’t necessarily see them every day. Routinely inspect your boiler to ensure no water is leaking. Boilers can become corroded and damaged over time, and water can leak.
Leaks also occur due to excessive pressure, worn seals, and damaged gaskets. Turn your boiler off right away if you notice a leak, then inspect the fittings and pressure relief valve. Consult a professional if you detect corrosion, as the boiler may need to be replaced.
5. Exorbitant Bills
High energy bills are among the first signs of many common HVAC problems. Most people expect their bills to increase during the peak of summer and winter, but only by so much. However, extreme bill increases often point to problems with your furnace or AC.
As usual, you should start by checking your air filter, as a dirty filter can raise your bills. Next, check the blower motor for strange noises and physical changes, or damage. Unfortunately, there’s a chance that your AC or furnace is too old or damaged.
Old ACs and furnaces must overwork, which can explain why your bills are so high. AC units typically last 15 to 20 years, and furnaces typically last 15 to 30 years. If the cost of repairs totals thousands of dollars, you’re better off replacing the unit.
6. Faulty Pilot Light
Some people struggle to keep their boiler's pilot light lit during the fall and winter. Without it, you can’t run your furnace, so you must troubleshoot everything you can before calling a professional. Sometimes, a pilot light can go out for simple reasons, like a heavy draft, which is the best-case scenario.
However, you may be dealing with a dirty pilot light, which you must carefully clean. To do so, turn the furnace and gas off, then clean the pilot light orifice with compressed air. Avoid using chemicals to clean the pilot light, as that is a big fire hazard.
You can also use a soft wire brush, but make sure you don’t apply too much force. If cleaning the pilot light orifice doesn’t work, you may need to replace the thermocouple.
7. Faulty Thermostat
Does the temperature on your thermostat match the temperature in your home? If not, it can indicate some problems with the thermostat, which are mostly easy to fix. To start, replace the batteries in the thermostat, as low batteries cause many issues.
If that doesn’t work, you may be dealing with faulty wires, which is a trickier problem to fix. This is likely the case if your furnace stays on when the thermostat is off. In that case, you must hire a licensed electrician or HVAC technician to fix the problem.
Otherwise, you may simply need to replace your thermostat if it’s over 10 years old. Thermostats only last 10-15 years in most cases, and their performance dips as they age.
8. Air Handler Failure
Each HVAC system has an air handler, which circulates the warm and cool air throughout your home. Like everything else, this component can grow faulty over time, and it will affect your comfort at home. First, you’ll probably notice that your HVAC system is loud when it operates.
This can happen because of issues with the dampers and blower motor. Such sounds often go hand-in-hand with inconsistent airflow throughout your home. Air handler failure can also cause short-cycling and increase your energy bills despite the weak performance.
The average cost to fix an HVAC air handler is $2,800, depending on which components are faulty. However, it may be a case where the air handler is one of many faulty components, and you may need to replace your system altogether. Otherwise, you can cheaply replace the blower motor for $400 to $1,200.
9. AC Won’t Run
If your AC won’t run, it could be due to several reasons, such as a failed capacitor. The capacitor is a crucial AC component that stores and uses energy to turn your system on and off. Capacitors provide the initial “push” to start your AC, which can’t happen if the capacitor is in bad shape.
The fan may still work, but you won’t feel any cool air coming from your air ducts. You must typically replace this part altogether, which is best left to professionals. Replacing an AC capacitor costs $250, on average, or up to $400.
10. Ductwork Leaks
Do you notice uneven temperatures, high bills, and weird sounds under parts of your air ducts? If so, that likely means that your ductwork is leaking. This can happen due to poor installation, but it also happens naturally due to gravity.
Air ducts sometimes sag and come apart at the connections, which creates gaps and causes air to leak. Not only does this make your home feel uncomfortable, but it can also waste money. The air won’t be delivered throughout your home as intended, so the heating and cooling energy gets wasted.
Hopefully, only one section of your ductwork needs to be fixed, and if that's the case, you can expect to spend $600, on average, to repair a single section. However, sealing several sections of ductwork can cost between $500 and $4,000, depending on the severity of the problem.
Summing It Up
Familiarize yourself with problems associated with dirty air filters, like poor airflow and high energy bills. It’s also important to listen to your HVAC system, as banging and thumping sounds can indicate air handler problems. Call an HVAC service right away if you smell electrical burning odors or see water in front of your boiler or AC.
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Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.
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