Your AC stops blowing cold air on a 95-degree Westminster afternoon. Now you're weighing a repair bill against a full replacement — and you don't know what a replacement actually costs. That's a stressful spot to be in. This guide answers exactly how much it costs to replace an AC unit in Westminster, CO, so you can make a clear decision before you call anyone.

Quick Answer: What Does AC Replacement Cost in Westminster, CO?

In Westminster, CO, replacing a central AC unit typically costs between $3,800 and $7,500, installed. The final number depends on your home's square footage, the efficiency rating of the new unit (SEER2), and whether your existing ductwork needs any work. Larger homes or systems that require ductwork upgrades can push the total above $10,000. Premium variable-speed systems run $7,500–$11,000 or more.



Ready to get a local number for your home? Visit our air conditioning repair Westminster CO page to schedule a diagnostic or request a replacement quote.

What Affects the Cost to Replace an AC Unit in Westminster?

Several factors move the price up or down. Knowing them helps you read quotes and avoid surprises.

Home size and unit tonnage. Larger homes need larger systems. Westminster homes typically require units between 1.5 and 5 tons. A unit that's too small will run constantly and wear out fast. Sizing is done with a Manual J load calculation — any reputable contractor should perform one before recommending equipment.

SEER2 efficiency rating. SEER2 replaced the old SEER standard for new equipment in January 2023. Higher SEER2 ratings mean lower monthly utility bills, but they come with a higher upfront cost. Deciding how much efficiency to buy depends on how long you plan to stay in the home.

Brand and equipment tier. Entry-level systems cost less to buy but may cost more to operate over time. We install brands like Amana and Lennox because they offer reliable performance across a range of budgets.

Ductwork condition. This is the most-overlooked cost factor we see on Westminster service calls. Homeowners often don't ask about ductwork until they see a line item on the invoice. Leaky, undersized, or damaged ducts can add $500–$2,000 or more to a replacement job.

Labor and permit costs in Jefferson and Adams County. Westminster spans both counties, and permit requirements apply to HVAC replacements. Permit fees and labor rates are part of your installed cost.

AC Repair vs. Replace — How to Decide in Westminster

This is the question most Westminster homeowners are really asking. Here's a practical way to think through it.

The $5,000 Rule. Multiply your system's age (in years) by the cost of the repair being quoted. If that number exceeds $5,000, replacement is usually the better financial move. For example: a 10-year-old unit with a $600 repair = $6,000 — lean toward replacement.

Age matters in Colorado's climate. Systems over 12–15 years old face a combination of efficiency loss, refrigerant challenges, and parts availability issues. Colorado's high-altitude climate and wide temperature swings put extra wear on equipment.

The R-22 refrigerant phase-out. Older units that use R-22 refrigerant can no longer be recharged affordably. The EPA phased out R-22 production, making it scarce and expensive. If your system runs on R-22, a refrigerant leak is often the tipping point toward full replacement.

When repair still makes sense. If your unit is under 8 years old, properly sized, and facing a single-component failure, repair is likely the right call. A diagnostic gives you the information to decide.

One Westminster homeowner called us for a refrigerant recharge on a 13-year-old unit. After inspection, we showed them that a replacement would pay for itself in roughly four summers through energy savings alone. They had the numbers — and they made the call.

Should You Repair or Replace? — 5 Quick Questions

• [ ] Is your unit 12 years old or older?

• [ ] Have you had two or more repairs in the past two years?

• [ ] Does your system use R-22 refrigerant?

• [ ] Is the repair quote more than half the cost of a new system?

• [ ] Are your energy bills noticeably higher than they used to be?

If you checked two or more boxes, replacement is worth a serious look. Schedule a diagnostic with our team: air conditioning repair Westminster CO

What to Expect From an AC Replacement in Westminster

Knowing what the process looks like takes the stress out of the decision.

Timeline. A standard AC replacement in Westminster takes 4–8 hours. If ductwork repairs or upgrades are needed, the job may run longer. We'll give you a clear scope before we start.

What a reputable company should include:

• Manual J load calculation to properly size the new system

• Permit pull with Jefferson or Adams County

• Removal and disposal of your old unit

• Startup testing and refrigerant charge verification

Questions to ask any contractor before signing:

1. Will you pull a permit for this job?

2. What brand and model are you installing, and what's the SEER2 rating?

3. What warranty covers parts and labor?

4. Will you do a load calculation before recommending a size?

5. What's included in the installed price — any ductwork inspection?

We always pull permits for Westminster replacements. It protects your equipment warranty and your home's resale value. Skipping a permit can create problems when you sell.

Financing. Many manufacturer programs and HVAC contractors offer financing options for qualified buyers. Ask about available terms when you request a quote.

5 Things to Confirm Before Your AC Installation Day

1. Permit has been pulled with the correct county

2. Equipment brand, model, and SEER2 rating confirmed in writing

3. Old unit removal and disposal included in the scope

4. Access to electrical panel and refrigerant lines is clear

5. Someone will be home for the full installation window