Buying a home? 10 HVAC questions that could save you thousands

• Homebuyers should ask about the age, maintenance history, and any major repairs of the HVAC system.
• The condition of the ductwork, energy efficiency ratings, and any existing warranties are also important factors.
• Red flags include missing maintenance records, equipment older than 10 years, and unusually high utility bills.

Buying a home is one of the most exciting yet stressful experiences. You spend hours scouring new listings, scheduling showings, touring homes and, ultimately, submitting offers. When you finally get one accepted, it feels like you've won the lottery.

Your journey isn't over, however. The next hurdle you need to clear is the home inspection.

While most buyers focus on the roof, foundation and plumbing, the HVAC system deserves just as much attention. Heating and cooling equipment can be one of the most expensive systems to repair or replace, and problems aren't always obvious during a walkthrough. Asking a few simple HVAC questions before you sign on the dotted line can help you avoid costly surprises and make a more informed purchase.

USA TODAY talked the the HVAC experts at ARS to learn the most important question to ask the seller about their HVAC system.

Why the HVAC system matters more than you think

Your home's HVAC system, which often includes an air conditioner, furnace and/or heat pump, is one of your home's most expensive mechanical systems. A single unit can cost you more than $10,000 on its own, but more complex projects can cost upwards of $30,000.

While some HVAC issues are easy to spot during a showing, many problems can be masked. More are easily overlooked or simply unknown. Yet, there are several things that indicate something is wrong with an HVAC unit. Asking just a few questions can unearth the problems that live underneath the surface.

10 questions to ask the seller about the HVAC system

1. How old is the HVAC system?

The HVAC system's age is one of the most important factors to consider, and could the the biggest indicator that you'd need to replace the unit. "Once you start getting over 12 to 15 [years], that's when the more expensive componentry starts to see end of life," adds Ken Turner, HVAC sales manager at at YES! Heating, Air Conditioning, Plumbing and Electric℠.

2. Has the system been regularly maintained?

When homeowners taken care of their HVAC systems, they last longer. Sellers should be able to produce service records or maintenance documents to prove that their air conditioners and heating systems have been professionally maintained.

Failure to share these records is a clear red flag. "If someone's saying that they're maintaining the equipment, most heating and air companies will give customers that documentation," says Turner. If they can't, there's a good chance preventative maintenance has not been performed regularly.

3. Has the HVAC ever needed major repairs?

Past problems can predict future ones. Besides regular maintenance, it's important to know about any major repairs that have been done. This information tells you a few things about the condition of the system.

For example, regular refrigerant leaks could mean there is a problem with an air conditioner's coil; multiple compressor repairs might indicate a new air conditioner is on the horizon. Ask the seller for HVAC repair records alongside maintenance records.

4. What type of heating and cooling equipment is installed?

You should walk away from any showing knowing what type of HVAC system is installed (and what might be missing). Not all homes have a complete cooling and heating system, so you may need to factor those comforts in if they are something you can't live without.

For example, a home might have a furnace for heat but lack a whole-home air conditioner. You would have to weigh the pros and cons of installing one or relying on other ways to cool your home.

5. Are there any known comfort issues?

If you notice rooms that are much hotter or colder than others, it could mean the HVAC system is on the verge of replacement or that there is a leak in the ductwork.

Also, take note of what the thermostat says and compare it to what the home feels like. If there's a disparity, that could mean an issue. "If the thermostat's on and you can see it's not achieving the temperature it's supposed to be, that could be a very big visual cue of something not performing right," says Turner.

6. How energy efficient is the system?

Energy efficiency is important because it directly impacts your monthly energy bill. The most common energy efficiency ratings to know include:

• SEER2 (Seasonal Energy Efficiency Ratio 2): Measures the cooling efficiency of air conditioners and heat pumps. Higher SEER2 ratings indicate greater energy savings.
• EER2 (Energy Efficiency Ratio 2): Measures cooling efficiency at a specific outdoor temperature, providing a snapshot of performance during peak cooling conditions.
• HSPF2 (Heating Seasonal Performance Factor 2): Measures the heating efficiency of heat pumps over an entire heating season. Higher ratings mean lower heating costs.
• AFUE (Annual Fuel Utilization Efficiency): Used for furnaces and boilers to show how efficiently fuel is converted into heat. For example, a 95% AFUE furnace converts 95% of its fuel into usable heat.

7. What is the condition of the ductwork?

The home's ductwork is just as important as the HVAC units, and could be a major reason why a home's energy use is high. Think of ducts as the cardiovascular system of a home. Air flows through this series of connected tubes and delivers it to and from every room of the house. If the ducts aren't installed right or are blocked, even the most energy-efficient HVAC system will perform poorly.

You probably won't notice ductwork problems during a tour, and it's very possible it will get missed on a home inspection. Disconnected sections of ductwork, collapsed flexible ducts or heavy dust and mold buildup inside the walls can be nearly impossible to detect by just doing a sweep. Musty odors, excessive dust and strange hissing noise can mean problems with the ducts, but other problems can go unnoticed.

When buying a home, ask the homeowners about the ducts to find out their age and when (or if) they were last checked.

8. Are the air filters and indoor air quality components up to date?

HVAC systems can be more than just an air conditioners and furnace. A home's HVAC system might include air purifiers, UV lights, humidifiers and dehumidifiers that add extra layers of comfort. Home air purifiers can be great additions if you or a member of your family suffers from allergies, and a home humidifier can feel like luxury during cold, dry winters.

As you explore the home and get inspections, you'll want to know about the age, maintenance records and current condition of these systems.

9. Is the system still under warranty?

Most manufacturer warranties last between five and 10 years, and if your HVAC system is still under warranty, you'll want to make sure that transfers when you buy the home.

"Anything over 10 years is going to be outside of the manufacturer warranties," says Turner. This is where an extended home warranty can come in handy. The seller may have one already, or it could be included in the sale of the home to protect against unexpected breakdowns.

10. Should you get a separate HVAC inspection?

A general home inspection will look at the HVAC, but it won't go as in-depth as a separate HVAC inspection would. Home inspectors typically verify that the system operates and look for obvious signs of damage or wear, while HVAC professionals can evaluate components such as refrigerant levels, airflow, electrical connections, ductwork and overall system performance.

An additional HVAC inspection might be a good idea if equipment is older, maintenance records are unavailable or the system shows signs of potential problems.

Red flags that require buyers to take a closer look

The most glaring red flags are the ones that are hard to miss, like visible corrosion or a system that doesn't turn on. Other red flags are more subtle. Here's what should set off some alarms if you encounter them while looking at a house:

• Missing maintenance records
• Very old equipment (anything over 10 years warrants a closer look)
• Frequent repairs
• Unusually high utility bills
• Visible rust, corrosion or neglected components

7 Quick HVAC questions to ask the seller

These seven questions will tell you everything you need to know about the state of a home's HVAC system:

1. How old is the HVAC system?
2. When was it last serviced?
3. Have there been any major repairs?
4. Are maintenance records available?
5. Is any warranty coverage transferable?
6. Have there been comfort or airflow issues?
7. What were the average utility costs for heating and cooling?