Last Revised: 9/1/26
Buying a house should be an exciting experience, but it doesn’t come with a roadmap and any decision you make could feel like a wrong turn. The process is rarely straightforward, so some level-headed guidance from someone who’s been there before can make the seemingly complicated simple.
The Mattionis can’t tell you which house your family should call home, but when you do find your next home, we can give you the full picture on all things HVAC and plumbing. So you know exactly what you’re getting yourself into.
Here’s what you need to be doing today, so that you’re on the right track tomorrow.
What Do I Need to Know About HVAC Before Buying a Home?
When you’re touring homes, the HVAC system is easy to overlook. It’s not as photogenic as a kitchen remodel, but glossing over it before signing paperwork can lead to some serious question marks over your head later. Here’s the skinny on what to know about HVAC before you buy.
Bring this to your next walkthrough: Questions to ask the seller or their agent
- How old is the furnace, and how old is the air conditioner or heat pump?
- Is there a manufacturer warranty still active, and can it transfer to a new owner?
- Do you have service or maintenance records from the past few years?
- Has the system had any major repairs? If so, what and when?
- When was the ductwork last inspected or sealed?
- What type of thermostat is installed, and how old is it?
1. Get the Equipment’s Age
Start with the basics. How old is the furnace? How old is the air conditioner? It’s a simple number that’s really important to look at. There’s not a magic wand that gets waved over these systems when you inherit them. They are what they are, and their ages are a great place to start learning about what you’re getting into.
Their manufactured date is usually printed on the unit itself, or your real estate agent can request it from the seller. Generally, air conditioners and heat pumps last 12-15 years, and furnaces can last closer to 20. A system installed in the last 3 years is a green flag. If the system is over 10 years old, the replacement costs coming in the next few years are something to consider, even if they’re still running fine today.
2. Ask About Remaining Warranties
HVAC manufacturer warranties usually run 5 to 10 years, and are sometimes transferable to a new homeowner if registered properly. You’re well within your rights to ask the seller or their real estate agent whether any HVAC warranty coverages are still active and transferable.
If a critical component fails after you move in, an active warranty is the difference between a free repair and one that comes out of your pocket.
3. Verify the Outdoor Unit’s Condition
Take a slow, thorough walk around the outdoor AC unit to check its condition. Make sure there’s 1-2 feet of clearance around it and that the coils are clean. A coil packed with leaves, grass clippings, or mulch indicates the equipment has been running with poor airflow. In other words, it’s been working harder than it should.
That doesn’t mean it’s a deal breaker, a little TLC goes a long way towards providing proper airflow to the outdoor unit. But because it’s such an easy fix, poor clearance around the outdoor unit really does tell you a lot about how the less visible parts of the system have been treated.
Green Flags
- Systems installed within the last 3 years
- Coils are visibly clean with open clearance on the sides and back
- No rust, corrosion, or staining on the indoor equipment
- Seller has documented proof of annual tune-ups
Red Flags
- Systems over 10 years old
- Coil packed with debris, or crowded by fencing, mulch, or shrubs
- Visible rust or corrosion, especially near the heat exchanger or flue pipe
- No maintenance records, or the seller can't answer basic questions
4. Check the Indoor Equipment for Rust, Corrosion, or Leaks
Whether it’s a furnace in the basement or an air handler in a closet, you’ll want to take an up-close look yourself. Rust, corrosion, or any staining suggests there’s recently been a leak. Make sure any signs of a leak have been followed up on. In particular, it’s worth confirming with your inspector that there are no signs of corrosion around the heat exchanger or flue connections, as those directly impact safety.
A nice, clean unit shows that it’s been well-maintained and that it’s going to have the best chance of making it a long time. Period.
5. Why a Clean, Well-Maintained Unit Matters
None of these checks require any HVAC expertise. You should look for each of them during a walkthrough. Here’s what it boils down to:
You’re evaluating whether the system has been maintained on a regular schedule to assess how much longer it’s likely to run before it needs to be replaced. A clean, cared-for unit is far more likely to run efficiently and avoid surprise breakdowns than one that looks like it hasn’t been touched in ages.
A few extra steps worth taking before you close:
Get the system’s service and maintenance record from the seller or their agent. A homeowner who’s kept up with yearly tune-ups will typically keep a record of it. If it’s absent, you’ll want to know that too.
Consider a pre-purchase HVAC inspection by a licensed technician, separate from your general home inspection. A technician will catch things that a general inspector might miss.
Don’t stop at the equipment: ask about the thermostat’s age and type, and whether the ductwork has been sealed recently. Duct issues are known to quietly undercut a system’s efficiency.
Quick recap before you keep reading
Buyers: check the equipment's age, ask about a transferable warranty, and look for clean coils with proper clearance outside and no rust or corrosion inside. If you're not sure about its condition, a documented service history (or lack thereof) is the tiebreaker. Now here's the seller's side of the same conversation.
Sellers: Think Like a Buyer
Getting ready to list your home on the market? Here’s your short version: do everything above from the other side of the table. Get a proper inspection on your equipment before you list, especially if you have a gas-fired furnace. An HVAC tune-up done ahead of time confirms everything’s in tip-top shape and won’t cause any hiccups later down the line.
A clean unit and proof of maintenance reassure buyers the same way you’d want to be reassured. It’s an easy way to head off issues before a buyer’s inspector finds them for you.
Your HVAC can work against you, but it can also work for you and make your home stand out in a crowded market.
Get Peace of Mind Before You Buy or List
An HVAC system may appear to be in good working condition during your tour. Red flags can even go unnoticed by a general inspector. A comprehensive inspection is the only way to get the full picture. It’s not complicated: get eyes on the equipment, understand its age and condition, and receive a professional opinion before it becomes a surprise repair bill (or a sooner-than-expected system replacement).
That’s exactly what our technicians at Mattioni do every day. Give us a call at (610) 400-8510 or book online and we’ll send a licensed technician to inspect the system. We understand the stress that comes with both buyer’s pre-purchase and seller’s pre-listing. We’ll tell you plainly what shape it’s in and whether anything needs pressing attention.
The Mattioni family has been serving neighbors across Chester, Montgomery, and Delaware counties for more than 75 years. Our goal is simple: to give clarity to something that can feel complex. Because nobody should buy or sell a home wondering what’s really behind that HVAC closet door.
