Your AC breaks down in July. The tech gives you two options. How do you know which one makes financial sense? Here's the framework we use to help St. George homeowners decide.
Nobody wants to spend money on their HVAC system. So when your AC breaks down and a technician tells you it needs a major repair, you face a genuinely difficult decision: pay for the repair and keep running the existing system, or put that money toward a new unit? Here's how to think through it.
Start With the 5,000 Rule
One of the most practical frameworks for this decision is the 5,000 rule: multiply the age of your unit (in years) by the estimated repair cost. If that number exceeds $5,000, replacement is almost always the better financial decision.
For example: your AC is 9 years old and the repair is $650. 9 × $650 = $5,850. That's over the threshold — replacement likely makes more sense. If the system is 3 years old and the repair is $650, 3 × $650 = $1,950. Repair is clearly the right move.
Factor In Age and Efficiency
AC technology has improved dramatically in the past decade. Units manufactured before 2015 used R-22 refrigerant, which is now phased out and extremely expensive when it's needed for a recharge. If your older unit has a refrigerant leak, the cost of R-22 alone can make repair economically irrational.
Modern systems also operate at significantly higher efficiency ratings (SEER). Replacing a 10-year-old 10 SEER unit with a new 18–20 SEER unit can cut your cooling costs by 30–40% — savings that compound every month through St. George's long cooling season. In a climate where you're running AC 8+ months a year, efficiency gains have real dollar value.
When Repair Clearly Makes Sense
If your system is under 8 years old, has been well maintained, uses current refrigerant, and the repair is a single isolated component failure (capacitor, contactor, fan motor), repair is almost always the right call. These are mechanical components that fail on their own timeline regardless of system condition.
A well-maintained system in St. George can last 12–15 years. Getting there requires regular tune-ups and addressing minor issues before they cascade into compressor failure — which is where replacement becomes unavoidable.
When Replacement Makes Sense
Consider replacement seriously when: the system is 10+ years old, the compressor has failed (the most expensive single component), you're facing multiple repairs in the same season, the unit uses R-22 refrigerant, your energy bills have risen significantly despite normal usage, or the system simply can't keep up with summer heat the way it used to.
In Southern Utah's climate, an undersized or aging system doesn't just cost more to run — it struggles to maintain comfortable temperatures on 110°F days, which is when you need it most. A properly sized, efficient new system delivers meaningfully better comfort, not just lower bills.
Get a Second Opinion If You're Unsure
Any reputable HVAC company should be willing to give you an honest assessment of both options without pushing you toward the more expensive one. At Marlin, we give homeowners the complete picture — repair cost, expected remaining lifespan of the existing unit, and a replacement quote — so you can make an informed decision.
If a technician is pressuring you to replace without fully explaining why, or if the repair quote seems unusually high, a second opinion is always reasonable.
Marlin Plumbing Heating & Air
Serving St. George, Utah since 1978