Buying a Colorado Home This Fall? Your Inspector Probably Won’t Test the AC. Here’s What to Do About It.

By Prerna Kapoor, CLHMS | REAL Brokerage | September 16, 2026

Last October I had a buyer under contract on a home in Castle Rock, and the inspection report came back with a line most people skim right past: “Cooling system not operated due to outdoor temperature.” The AC was a 16-year-old unit. Nobody knew whether it worked. And the seller had already blown out the sprinklers the week before, so that system sat untested too.

That’s the quiet reality of buying a home in Colorado between October and April. Some of the most expensive systems in the house simply can’t be checked, and the inspection report will say so in one polite sentence. Here’s what actually gets skipped, why, and how I help buyers protect themselves anyway.

The 65-Degree Rule Nobody Mentions at the Showing

Home inspectors follow written standards, and the big one in this state is InterNACHI’s Standards of Practice. Those standards say an inspector is not required to operate cooling equipment when the exterior temperature is below 65 degrees Fahrenheit, or in any other conditions that could damage the equipment. Running a compressor in cold air can genuinely hurt it, so this isn’t inspectors being lazy. It’s them protecting the seller’s equipment and their own liability.

Along the Front Range, that threshold arrives sooner than people expect. The National Weather Service puts Denver’s average first freeze at October 7, and plenty of October mornings never climb past the low 60s. So if your inspection lands on a cool day, the air conditioner gets a visual look, a check of the age and data plate, and nothing more.

I see this most in Parker, Castle Rock, and Highlands Ranch resales from the early 2000s, where the original AC units are now pushing 20 years. A replacement in that size range often runs well into five figures, and it’s the single largest item a fall inspection routinely leaves blank.

Sprinklers, Swamp Coolers, and Everything Else That Gets Winterized

By mid-October, most Denver-area sellers have had their irrigation system blown out. Once the lines are drained and the backflow is shut, an inspector can’t test zones, heads, or the controller. A cracked line or a dead valve won’t show up until you turn the water back on in April. I wrote about what that spring turn-on should look like in this irrigation checklist, but the point here is that you’re buying that system on faith.

Evaporative coolers, still common in older Denver and Aurora homes, get drained and covered the same way. Hot tubs and pools are usually winterized too. And if there’s snow on the roof, the inspector walks what they can see and notes the rest as “not visible.” In a real Colorado winter, that can be most of it.

None of this means skip the inspection. It means the report has gaps, and you need a plan for each one.

What Still Works Perfectly Fine in Cold Weather

Some checks actually get better in the off-season. Furnaces and boilers run under real load, so the inspector sees the system doing its job rather than idling on a mild day. Radon testing is often more reliable in fall and winter because homes are closed up, which is the condition the EPA wants for a short-term test anyway. That matters everywhere in Colorado, since the entire state sits in the EPA’s highest-risk radon zone. My radon guide walks through what to expect.

Sewer scopes work year-round. So do electrical, plumbing under pressure, water heaters, attic insulation checks, and the whole interior. If anything, a cold-weather inspection is the best time to catch drafts, failed window seals, and ice-dam potential along the eaves.

How to Protect Yourself on the Systems That Can’t Be Tested

This is where your contract matters more than your inspector. The Colorado Contract to Buy and Sell gives you an Inspection Objection Deadline and an Inspection Termination Deadline, and your written objection is where untested systems get addressed. A few tools I use for buyers, depending on the situation:

Ask for the seller’s service records. A dated receipt showing the AC was serviced last summer, or the sprinkler system was running in September, tells you far more than a visual inspection ever could. Sellers who have them are usually happy to share.

Negotiate a home warranty as part of the resolution. Many plans cover HVAC failures, and a seller-paid first year is a common ask when a major system couldn’t be verified. I covered how those policies actually work in my home warranty guide.

Write a spring re-test into the deal. For irrigation especially, buyers sometimes negotiate a credit at closing, or an escrow holdback that releases once the system is tested. It takes a cooperative seller and a title company willing to hold funds, but I’ve done it.

Bring in an HVAC technician on a warm day. Colorado gives us plenty of 65-degree afternoons even in November. If one lands inside your inspection period, a licensed HVAC tech can safely run the system when a general inspector won’t. All of this belongs in the same conversation as your inspection repair negotiation, not as an afterthought.

Why I Still Like Fall and Winter for Buyers

I don’t want this to read as a warning against off-season buying. It’s usually the opposite. Fewer buyers are looking, sellers who list in November tend to have a real reason to sell, and the negotiating room on inspection items is often wider than in May. The tradeoff is that you carry a little more uncertainty on a couple of systems, and you manage that uncertainty with paperwork instead of a test.

If you’re heading into an inspection in the next few months, read the report for the words “not operated” and “not visible” before you read anything else. Those lines are where your negotiation should start. And if you want a second set of eyes on one, I’m always happy to look. No pressure, no pitch.

Quick answers

Why won’t my Colorado home inspector test the air conditioner in the fall?
Industry standards allow inspectors to skip operating cooling equipment when the outdoor temperature is below 65 degrees, because running a compressor in cold air can damage it. The unit gets a visual review only, and the report should say so.

Can I still negotiate over a system the inspector couldn’t test?
Yes. Your written inspection objection can request service records, a seller-paid home warranty, a closing credit, or an escrow holdback tied to a spring re-test. The key is raising it before your Inspection Objection Deadline.

Is winter a bad time to get a home inspection in Colorado?
No. Furnaces get tested under real load, radon tests are more reliable with the house closed up, and sewer scopes work year-round. The main gaps are AC, irrigation, and anything under snow.

Prerna Kapoor | REALTOR® | Luxury Home Specialist
REAL Brokerage | 720-949-5450 | info@prernakapoor.com
CLHMS • RENE • PSA • ABR | International Sterling Society Award Winner

Prerna specializes in residential real estate across Parker, Aurora, Lone Tree, Castle Pines, Highlands Ranch, Cherry Creek, Greenwood Village, and Centennial. She speaks English, Japanese, and Hindi.