Troubleshooting10 min

When to Repair vs Replace Your HVAC System: The Complete Decision Guide

Use the 50% rule as your starting point: if the repair costs more than 50% of a new system's price, replacement often makes more sense.

By Kodiak HVAC TeamUpdated January 6, 2026

Quick Answer

The repair vs. replace decision depends on your system's age, repair cost, and efficiency. General rule: if your AC is over 10 years old AND the repair costs more than 50% of replacement cost, replacement usually makes more sense. Also consider if you've needed multiple repairs recently—frequent problems signal a system near end of life.

Your AC breaks down. You call for service and the technician tells you it needs a major repair. Now you're faced with a tough question: should you pay for the repair, or is it time to invest in a new system?

This is one of the most common questions we hear, and there's no one-size-fits-all answer. But there IS a logical framework for making this decision. Let's walk through it step by step.

The 50% Rule: A Starting Point

A widely-used rule of thumb: If the repair costs more than 50% of what a new system would cost, replacement is usually the smarter financial choice.

Simple Math Example

New AC system cost: $6,000. Repair cost: $3,200. That's 53% of replacement cost. Unless your current system is relatively new (under 8 years old), replacement likely makes more sense.

But this rule alone doesn't tell the whole story. Age, repair history, and efficiency all factor in.

The Age Factor

How old is your current system? This matters a lot:

System AgeGeneral RecommendationWhy
Under 8 yearsRepair (usually)Still has significant life left
8-12 yearsDepends on repair costEntering middle age
12-15 yearsConsider replacementEfficiency declining, parts aging
Over 15 yearsReplace (usually)Past expected lifespan

AC systems typically last 15-20 years with good maintenance. Once you're past 12-15 years, even a successful repair may be followed by another failure soon. You're essentially putting money into a system with limited life remaining.

The Repair History Factor

Is this the first repair, or has your system needed work before? Track record matters:

  • First major repair in 10+ years: Repair probably makes sense
  • Second repair this year: System may be on its way out
  • Third or more repair in 2-3 years: Replacement is likely smart

The Domino Effect

When major components fail, other parts of similar age often follow. A compressor failure on a 12-year-old system is often followed by capacitor, contactor, or blower motor failures within the next year or two.

The Efficiency Factor

Older systems are less efficient than new ones—sometimes dramatically so. If your system is 15+ years old, it's probably rated around 10-13 SEER. Modern minimum efficiency is 14 SEER, with most systems at 16-20 SEER.

What does that mean for your wallet?

Annual Cooling Cost Comparison (3-ton system)

10 SEER (15+ year old system)
$720/year
Typical older system
14 SEER (minimum today)
$515/year
28% savings
18 SEER (mid-range new system)
$400/year
44% savings

Over 10-15 years, these savings add up to thousands of dollars. Factor this into your repair vs. replace calculation.

Specific Repairs: When to Repair vs. Replace

Usually Worth Repairing (Any Age)

  • Capacitor: $200-$300
  • Contactor: $250-$400
  • Thermostat: $200-$800
  • Refrigerant recharge (small leak): $200-$800
  • Drain line cleaning: $200-$300

Repair If Under 10 Years, Otherwise Consider Replacement

  • Blower motor: $400-$900
  • Fan motor: $400-$800
  • Refrigerant leak repair: $200-$800
  • Control board: $400-$800

Often Better to Replace (Unless System Is New)

  • Compressor: $1,500-$3,500
  • Evaporator coil: $1,800-$3,500
  • Multiple components failing together

The Decision Framework

Use this step-by-step process:

Making Your Decision

  1. 1

    Get the repair cost

    Get a written quote for the repair from a reputable company.

  2. 2

    Calculate the percentage

    Divide repair cost by estimated replacement cost. If under 50%, lean toward repair.

  3. 3

    Check your system's age

    Over 12-15 years? Factor in limited remaining lifespan.

  4. 4

    Review repair history

    Multiple recent repairs? The trend may continue.

  5. 5

    Consider efficiency

    Old system? A new one could pay for itself in energy savings.

  6. 6

    Factor in your plans

    Selling soon? Repair may make sense. Staying long-term? Investment in new system pays off.

Real-World Examples

Example 1: Repair Makes Sense

Situation: 7-year-old Trane system needs a blower motor ($650 repair). No prior major repairs. System runs efficiently.

Decision: REPAIR. System has 8-13 years of life remaining. Repair cost is about 10% of replacement. First major repair in 7 years is normal.

Example 2: Replacement Makes Sense

Situation: 14-year-old system needs compressor ($2,200 repair). Replaced blower motor last year ($600). System is 10 SEER.

Decision: REPLACE. Repair is 35% of replacement cost, but system has maybe 3-5 years left. Already had a recent repair. New system would cut energy bills 30-40%.

Example 3: Borderline Case

Situation: 10-year-old system needs evaporator coil ($1,500 repair). No prior major repairs. 13 SEER.

Decision: COULD GO EITHER WAY. Repair is 25% of replacement—mathematically makes sense. But system is entering high-risk age range. Consider: Are you staying in the home long-term? Can you afford another major repair in 2-3 years if needed?

What We DON'T Do: High-Pressure Replacement Tactics

Some companies push replacement on every service call because they make more money on installations. Here's what to watch for:

  • "Your system uses old refrigerant that's being phased out" – R-22 was phased out, but repair is still often viable
  • "Parts for your system aren't available" – Rarely true for systems under 20 years
  • "It would be dangerous to keep running it" – Unless there's a cracked heat exchanger or major electrical hazard, this is exaggeration
  • No option given to repair – A good company presents both options with honest pros/cons

At Kodiak, our technicians are paid hourly—not commission. We don't benefit from pushing replacement when repair makes more sense for you.

Frequently Asked Questions

Need Help With Your HVAC?

$89 diagnostic fee waived with repairs. Same-day service available.

Frequently Asked Questions

It depends on the repair. Minor repairs ($150-$500) are usually worth it at 10 years. Major repairs (compressor, coil) are borderline—consider the system's history and condition. If it's been reliable and well-maintained, repair might make sense.
Usually no, unless it's extremely inefficient (under 10 SEER), uses R-22, or can't keep your home comfortable. "If it ain't broke" still applies—but schedule replacement before the next summer, not during.
Ask questions. A trustworthy contractor explains their reasoning, presents multiple options, and doesn't pressure you. Get a second opinion if you're unsure. Honest contractors welcome second opinions.
Yes. A new 16 SEER AC uses about 35% less electricity than a 10 SEER unit for the same cooling. Over 15 years, that adds up to thousands in savings—sometimes enough to offset the cost difference between repair and replacement.

Ready for a Free Estimate?

No pressure, no obligation. Get honest pricing for your HVAC project.

KHT

Written by

Kodiak HVAC Team

HVAC professional at Kodiak Heating & Cooling.

Need Help With Your HVAC System?

Our $89 diagnostic fee is waived with repairs. Same-day service available in Charlotte and surrounding areas.