You’ve found your dream home. Now, make sure you won’t get hit by a surprise repair bill once you get the keys.

One of the first items to evaluate when touring properties is the heating, ventilation and air conditioning (HVAC) system. The HVAC system regulates the air quality and temperature within a residence — and can be a deciding factor when you’re trying to choose between several properties.

HVAC systems typically have a lifespan of 10 to 15 years, so you might think an older system could be a red flag. But that doesn’t mean a buyer should overlook a home with an older HVAC unit. How long a heating and cooling system lasts depends not only on its age but also on how well it is maintained.

“In some cases, an eight- or nine-year-old system makes sense to replace. In other cases, you may have a system that’s 15 years old that still makes sense to keep,” says Joey Dooley, general manager at ARS/Rescue Rooter in Texas.

A typical home inspection can reassure a buyer that a unit is in working condition. But sometimes you need to dig a little deeper to ensure you won’t end up facing a substantial repair down the line.

Some telltale signs that a more in-depth HVAC review is needed include unusual noises (such as hissing, rattling or banging) and musty odors coming from the vents. Once the general inspection is complete, consider scheduling a specialized HVAC inspection during the contingency period of your purchase contract.

The cost of this checkup can range from $100 to $300, but it’s a wise investment in your future: An HVAC inspection can surface problems to address with the seller before you close on the property if significant repairs or a system replacement are needed.

Why HVAC inspections are important

Your heating, ventilation and cooling system circulates clean air throughout your home; filters out odors, moisture and pollutants; and keeps it at a comfortable temperature. Ensuring the HVAC system is working properly is important not only for your comfort but also for your health.

One of the first items an HVAC technician will look at is the unit’s age, the type of heating and cooling system, and the refrigerant the air conditioner uses. Older ACs that use Freon, for example, are largely better off being replaced, since that refrigerant was phased out beginning in 2010 and is now difficult (and expensive) to find.

After determining how old your HVAC unit is, the inspector will also look for signs of deferred maintenance, such as clogged air filters, dirty condensator and evaporator coils and worn-out belts. Other details the inspector will probably check include:

Equipment damage

Rust, cracks, water pooling around the unit, stains, dents and other physical damage could indicate minor issues that can be easily resolved… or a more serious problem that could require a major repair or replacement.

Ductwork integrity

The HVAC ducts allow heated or cooled air to flow throughout the home. Gaps, leaks, obstructions or loose connections in the ductwork can result in reduced efficiency, higher energy bills and uneven temperatures throughout the home.

Insulation

The right amount of insulation helps your HVAC system run more efficiently and lowers energy consumption. Some older homes may not have enough insulation to meet current efficiency standards.

At the same time, some materials, such as fiberglass or blown-in cellulose, may have compressed and settled over time, creating gaps and losing their temperature-controlling properties. If the insulation has been exposed to water, it can become a breeding ground for mold, creating additional problems for the homeowner.

Efficiency

Your inspector will also verify the HVAC system’s Energy Star rating, ensure it is working efficiently and confirm that the unit is the correct size for the home. A unit that is too small for the coverage area will work overtime to maintain a constant temperature, leading to increased energy consumption and higher utility bills.

How an HVAC inspection can influence your home purchase negotiation

Once the inspector has examined all aspects of your heating and cooling system, you’ll receive a written report detailing the findings, including any potential problems and the recommended course of action.

The results from this report can provide significant leverage during your contract negotiations. If the inspector finds that the HVAC system is nearing the end of its life span, you may request some form of seller concession, including:

• A seller cash credit towards closing costs
• A purchase price reduction to cover the cost of a future repair/replacement
• Seller-funded repairs

Another option is for the seller to agree to purchase a home warranty that covers repair costs for a specific period, typically the first year of new ownership, which can give the prospective buyer some time to budget for repairs later on.

However, at some point, the buyer will have to decide whether investing in a home with an HVAC system nearing the end of its useful life is worthwhile. An HVAC inspection report can make that decision easier.

“If one home has a newer, high-efficiency AC system and another home has a system that looks like it’s on its last legs, the house with the better system is more attractive,” Dooley says.