It’s often ignored even though the heating ventilating and air conditioning (HVAC) system is one of the most important components of your home’s ecosystem. The HVAC system helps keep you comfortable by circulating air throughout your home and filtering out allergens in the air. The HVAC system is what also allows us to maintain enjoyable indoor temperatures separate from the outside environment.

Many homeowners aren’t even aware their HVAC system is running inefficiently until it completely stops working or causes an increase in the energy bill. At this point, many homeowners will then contact their local HVAC company where they'll be recommended to

70% of residential HVAC systems are performing below standard.

buy a new replacement system. This reactive approach to servicing your home’s HVAC system is more expensive and often times avoidable. HVAC systems typically don’t break overnight, instead, they slowly become inefficient over time with a series of small malfunctions throughout the system.

The best way to go about maintaining an HVAC system is to have a set plan that you follow every year. In this guide to HVAC maintenance, we’ll go over the basics that you need to know in order to put a plan into place, including what goes in to proper maintenance, how often you should do it, and how much it costs.

Schedule of Maintenance Tasks:

Once a month

  • Inspect your air conditioner refrigerant lines for leaks. These two lines, which are typically copper, connect your outdoor air conditioner to your system’s indoor evaporator coil.

Once a season

  • Replace the air filter every 90 days.
  • Turn off water to the furnace humidifier in the summer.
  • Replace the humidifier filter and turn water back on in the fall.

Once a year

  • Go through your home and replace the batteries in all of your carbon monoxide detectors.
  • Lubricate your HVAC motor and replace the fan belt if it’s not running efficiently.
  • Clean your AC condensation drain line with bleach to prevent the build-up of mold and mildew. Directions on how to do that here and here.
  • Take a look at your outdoor AC unit and ensure that, in addition to being free of debris, the unit is standing on level ground.

If you follow this list and make sure to do the right tasks at the right times, your HVAC system should run well for a long time. The life expectancy of an HVAC system is about 10 to 25 years—and with preventative maintenance you can expect yours to last closer to 25 than 10.

Most HVAC units are a “split system.” This just means some of your components are indoors, and some are outdoors. For the next step in your DIY HVAC inspection, head outside to make sure that your outdoor unit’s compressor and blower are in good condition. The outside unit can usually be found behind or to the side of the house on a small concrete slab.

Now head indoors and locate your furnace.

Check your filters every month. At least once a season, you should change the furnace filters which help by preventing dust and debris from getting in and slowing things down. This video by Van Metre Customer Care provides a good explanation for how to do that.

You can also check out this 1-minute video with a clearer visual to locate the furnace filter.

What about hiring an HVAC technician to come in?

Even though you can handle most of the standard HVAC maintenance tasks on your own, your heating and cooling system is rather complex, and some issues might not be apparent to you. In the same vein, there are more nuanced checks that need to be done occasionally, such as checking for proper functioning of electric components and ductwork.

It’s a good idea to occasionally bring in a pro for HVAC maintenance. If your system is new you can probably get away with having someone come just once a year or every other year. For older systems, plan to have professional maintenance performed twice a year—in the spring and then again in the fall.

HVAC maintenance and repair costs

Your HVAC system isn’t going to cost you too much if you stay on top of preventative maintenance. Costs to budget for include high-efficiency air filters, which are about $20 apiece (you’ll need four per year) and a bottle of bleach for cleaning drain lines—about $5.

If you hire a technician to come in and perform maintenance, expect to spend about $70 to $100 per visit. Ask about any discounts that might be available. Some HVAC maintenance companies also offer annual contracts, where you pay a set fee to have someone come out once a year.


Repairs are where things start to get pricey. Here are average HVAC repair costs, according to HVAC.com:

Repair blower motor: $150
Replacement blower motor: $450
Thermostat replacement: $50 to $200+
Replacement ignitor: $300 to $400
Repair flame sensor: $80
Replacement flame sensor: $250
Repair heat exchanger: $100
Replacement heat exchanger: $500 to $1,200
Repair pressure sensor/circuit board: $50
Replacement pressure sensor/circuit board: $350
Replace gas valve: $150
Replacement smart valve: $750
Replacement draft inducer: $150 to $450

Keep in mind that these costs are averages, and that your exact costs will vary depending on your system’s type and age. As for the cost to install an entirely new HVAC system? That’s about $6,000 to $12,000, which is definitely enough to warrant staying on top of your maintenance task list.

Stay up to date with HVAC maintenance and you can help prevent a lot of the common problems that lead to expensive repairs. And as always, when in doubt, bring in a pro.