It’s no secret that service calls for home repairs can be pricey.

Every once in a while you’ll come across companies that don’t charge an initial fee to come to your home, but that’s the exception rather than the rule—gasoline ain’t free, my friends, and neither is fleet vehicle maintenance. Home service and repair companies have to cover their costs somehow.

Depending on where you live, the cost for an HVAC technician to simply come to your home to investigate an issue can average around $100. If the problem has a simple fix—even if it’s something you could have taken care of yourself—you’re still out the fee for the service call.

If your HVAC system is nearing the end of its life or has had problems in the past, a visit from a reputable HVAC technician isn’t a bad idea. If your system is only a few years old, however, the chances of you being able to fix the problem on your own are in your favor.

So, in the interest of saving yourself a little money, stay with me as I cover some common HVAC problems and how to fix them without the help of a pro.

Common HVAC Problems (and How to Fix Them)

close-up image of hvac fan

1. System doesn’t run

Unless it’s the middle of one of those gorgeous spring or fall days where some open windows are all you need to stay comfortable, an HVAC system that doesn’t run is a nightmare. Your first clue that there might be a problem usually comes from a thermostat that won’t turn on.

How to fix it:

Before you panic, remember that HVAC systems require electricity to work. Start with your home’s main electrical panel:

  • Do you see any tripped breakers or blown fuses? If so, reset the breaker or replace the fuse.
  • If the breaker immediately trips again or the fuse blows, there’s likely a more urgent problem at play. Call an electrician.

If there are no tripped breakers or blown fuses, check the thermostat. When was the last time you changed the batteries?

  • Carefully remove the thermostat’s faceplate to determine the correct battery size.
  • Replace the batteries and faceplate.

Finally, take a look at the furnace unit. Is it unlatched? Most furnaces have a safety feature that prevents the unit from operating if the furnace door isn’t fully closed.

  • Open the furnace door and turn the unit off (if it isn’t already).
  • Wait a few minutes, then close the door fully and turn the unit back on.

If the HVAC system still doesn’t work, call a pro!

2. System runs all the time

This can be a tough problem to troubleshoot on your own, but it’s definitely worth a try. First, consider the outside temperature. If your area is in the midst of a record heat wave, any HVAC system will need to run almost continuously to maintain the temperature you set at the thermostat. Similarly, extremely cold temperatures will cause heat pumps to run frequently.

How to fix it:

dirty pleated furnace air filterIf the weather isn’t overly hot or cold, restricted airflow could be causing the HVAC unit to work too hard.

Start with your HVAC unit’s air filter. Air has a hard time passing through a dirty filter, which means that your HVAC system must work harder to maintain the temperature set at the thermostat.

  • Generally speaking, air filters should be changed quarterly. If you have pets, allergies, or open your windows frequently, replacing the air filter monthly is not a bad idea.
  • If you’ve purchased fiberglass or pleated paper filters in the past, consider springing for a higher quality electrostatic filter.

If your filter is clean or has been recently replaced, check your thermostat settings. If they’re too low or too high, your unit will struggle to maintain (or even reach) the set temperature, which will cause it to run constantly.

  • In the summer, try to keep your thermostat set to 78 degrees Fahrenheit.
  • In the winter, set your thermostat to 68 degrees Fahrenheit.

These temperature settings will prevent your HVAC system from working too hard—and running up sky-high utility bills.

Overnight and when you’re away from home, the US Department of Energy recommends setting your thermostat seven to ten degrees lower in the winter and higher in the summer to help save money and reduce the load on your home’s HVAC system. Install a smart thermostat so you don’t have to remember to change the thermostat manually.

3. Heat pump is blowing cold air on heat setting

According to HVAC repair companies, this is one of the most common complaints from homeowners. Heat pumps are still relatively new technology compared to traditional gas furnaces and boilers, and they do provide heat differently than many people are accustomed to.

Heat pumps provide warmth at a much slower rate than a furnace. In fact, the temperature of the warm air put out by a heat pump may be as much as 30 to 40 degrees cooler than that of a gas furnace.

So, while I’m not going to tell you that it’s all in your head, your fear that your heat pump is broken might, in fact, be all in your head.

How to fix it:

This isn’t so much a fix as a confirmation: use a thermometer to check the temperature of the air coming out of the supply vents. The easiest way to do this is with an infrared thermometer.

Note: If that sounds like an expensive tool you’ll never use again, I can assure you that they are actually very handy to have around the house, and you can find a decent one for about $20.

When the heat is on, the temperature of the air coming out of the supply vents should be higher than the temperature in the room. The temperature difference may not be much—don’t be alarmed if the supply air is only 85 or 90 degrees Fahrenheit.

If it’s the same temperature as the air in the room (or lower), your heat pump is malfunctioning, and you should call an HVAC technician.

When to Call an HVAC Technician First

HVAC repairman working on HVAC unit

While you can do some HVAC troubleshooting on your own, there are a few instances that warrant an immediate call for help.

1. Concerning odors

The first time you turn on your heat in the fall or winter, you’ll probably notice the smell of something burning. This should only last less than half an hour and is completely normal. If the burning smell lingers, there may a problem with the system.

Other odors you should not ignore:

  • Burning or smoldering wiring. Burning electrical wire has a very distinctive, metallic smell. This odor could be caused by parts that are failing or disintegrating, so be sure to contact a professional for help.
  • Natural gas. The smell of natural gas is hard to describe, but impossible to forget. Even if you have a natural gas-fueled furnace, you should not smell gas in your home. If you do, there’s a bigger problem at play—call a repair technician.

2. Unusual sounds

No HVAC system is going to be completely silent, but you should not hear loud or sudden popping, banging, thumping, or metallic scraping.

If you hear any of the above, turn your system off and place a service call. Strange noises usually indicate a part that is out of place or off balance, and those problems only worsen with time.

3. System continually trips circuit breakers or fuses

Electrical heating and air conditioning systems use a lot of power—so much, in fact, that they should be connected to their own dedicated circuit on your home’s main electrical panel.

If your HVAC system trips a breaker or blows a fuse, there’s no need to immediately panic. Are you in the middle of a bad storm? Is your electrical service provider experiencing service outages? If so, ride out the storm or the service outage and then reset the breaker or replace the fuse.

If everything weather- and service-wise seems fine and the breaker immediately trips, your HVAC system—or electrical system—may have a problem. Electrical work can be dangerous, so don’t try to handle any issues yourself.

The Bottom Line

No one wants to hand over their hard-earned money without good reason, but when it comes to your home’s air conditioning and heating, there are some instances where that service call fee is worth every cent.

However, unless you’ve noticed electrical problems or strange odors or noises, check the following parts before picking up the phone:

  • Furnace filter
  • Main electrical panel
  • Thermostat setting
  • Thermostat batteries
  • Supply air temperature

And remember that preventative maintenance can go a long way toward reducing the need for service calls.

  • Change your air filters at least quarterly (once a month if you have pets or allergies).
  • Keep your thermostat set to reasonable levels.
  • Schedule a checkup visit twice per year—once in the fall and once in the spring—to make sure your system is ready for hot and cold weather.