Short answer: Use the 50% rule and the $5,000 rule to decide. If the repair cost exceeds 50% of a new system's price, replace. Multiply your system's age by the repair cost — if the result exceeds $5,000, replacement is the better financial move. In Las Vegas, AC units typically last 12–15 years due to extreme heat stress.
We get this question more than almost any other: Should I repair this or just replace the whole thing? It sounds simple, but for Las Vegas homeowners it carries real stakes. Your HVAC system runs harder here than almost anywhere in the country — 2,500 or more hours per year of runtime, attic temperatures that routinely hit 150°F, hard water that scales heat exchangers, and monsoon dust that clogs coils after every storm. A system that might last 18 years in Seattle is legitimately worn at 12 in the Mojave.
There is no single right answer, but there is a clear framework for reaching the right answer for your specific system, budget, and goals. We use it every day when our technicians walk homeowners through a diagnosis. Here is how it works.
The 50% Rule and the $5,000 Rule: Two Thresholds That Cut Through the Noise
Industry-wide, the two most reliable heuristics for repair-versus-replace decisions are the 50% rule and what we call the $5,000 rule. Used together, they give you a fast, defensible answer before you even think about energy savings.
The 50% Rule: If the cost of a repair exceeds 50% of what a new system would cost, replace. A full HVAC replacement in Las Vegas — new air handler, condenser, and coil — typically runs $6,000 to $15,000 depending on system size, brand, and whether ductwork modifications are needed. So: if a repair quote comes in above $3,000 to $7,500 (adjusted for your system's replacement cost), replacement is almost always the better financial move.
The $5,000 Rule: Multiply the system's age in years by the cost of the proposed repair. If that product exceeds $5,000, replace. Example: a 10-year-old system facing a $600 repair gives you 10 × $600 = $6,000 — above the threshold, so replacement is worth a serious look. A 4-year-old system with an $800 repair is 4 × $800 = $3,200 — below the threshold, repair makes sense. This rule accounts for the fact that an older system is statistically likely to need more repairs in the near future even after you fix today's problem.
Neither rule is absolute, but both give you a rational starting point instead of gut feel.
Age Thresholds: What Las Vegas Heat Does to HVAC Lifespan
National averages put air conditioner lifespan at 15 to 20 years. In Las Vegas, plan for 12 to 15 years under normal maintenance, and 10 to 12 years if the system has been undersized, poorly maintained, or running from an attic that lacks adequate ventilation. Furnaces fare better here — because heating season is short, a gas furnace can last 18 to 22 years in the Valley. Heat pumps fall in the middle, typically 12 to 15 years given year-round compressor use.
Use these age brackets as your baseline:
- 0–7 years: Repair almost anything short of compressor replacement on a large system. The equipment has substantial remaining life and a replacement would rarely pencil out.
- 8–12 years: This is the gray zone. Evaluate using the $5,000 rule. If the system has had multiple recent repairs, declining efficiency, or uses legacy R-22 refrigerant (which is no longer manufactured and costs $50+ per pound when available), lean toward replacement.
- 12+ years: Replacement wins more often than not. Efficiency gains from a modern system plus reduced repair risk usually outweigh the repair cost within 4 to 6 years in Las Vegas, where cooling costs are high.
One detail that matters a great deal here: find out your system's actual manufacture date, not the installation date. Check the data plate on the condenser or air handler — the first two or four digits of the serial number usually encode the production year. Systems installed in new construction can sit in warehouses for 12 to 18 months before installation, meaning your "10-year-old" system may actually be closer to 12.
For a closer look at HVAC maintenance practices that extend system life, our maintenance guide covers what to inspect and when.
Repair Cost Categories: What the Numbers Actually Mean
Not all repairs are equal. A $150 capacitor swap on a 14-year-old system is a very different conversation from a $3,200 compressor replacement on a 13-year-old system. Here is how we think about repair cost tiers in the context of Las Vegas systems:
Minor repairs ($150–$600): Capacitors, contactors, fan motors on smaller systems, thermostat replacements, refrigerant top-offs on a system with no active leak. At this cost, it almost never makes sense to replace unless the system is very old and you were already planning a change. Our AC repair technicians handle these same-day in most cases.
Moderate repairs ($600–$1,500): Evaporator coil cleaning with chemical treatment, blower motor replacement, minor ductwork sealing, hard-start kits, condensate system overhaul. Apply the $5,000 rule here. A $1,000 repair on a 6-year-old system (product: $6,000) is borderline — worth weighing against replacement if there is a history of other recent repairs.
Major repairs ($1,500–$3,500): Compressor replacement, condenser coil replacement, full refrigerant system overhaul after a major leak. This is where the 50% rule becomes essential. A $2,500 compressor replacement on a system where full replacement would cost $8,000 is 31% of replacement cost — potentially worth it if the system is young and otherwise healthy. The same repair on a 13-year-old system with corroded coils and an aging blower is almost never worth it.
One Las Vegas-specific caution: our hard water creates scale buildup on heat exchanger surfaces and in drain pans. We regularly see systems that look repairable on paper but have heat exchanger corrosion that means even a successful repair will fail again in 18 months. A thorough diagnostic — not just a parts swap — is essential before committing to a major repair on any system over 8 years old.
For a full look at heating repair options for furnaces specifically, we have a dedicated guide covering what is worth fixing versus when to upgrade.
The Energy Efficiency Math: When Replacement Pays for Itself
In Las Vegas, the efficiency argument for replacement is stronger than in most U.S. cities because we run our cooling systems so hard. A home that spends $250 per month on electricity in July and August, with HVAC representing 50 to 60% of that bill, is spending roughly $150 per month on cooling during peak months.
A modern 18 SEER2 system replacing a 12-year-old 13 SEER system can cut cooling energy use by 25 to 35%. On a $150 monthly cooling bill, that is $37 to $52 per month — roughly $400 to $550 per year. Over a 12-year system life, that is $4,800 to $6,600 in savings before accounting for utility rate increases (NV Energy rates have trended upward consistently). The efficiency payback period on a $9,000 replacement is often 7 to 10 years — reasonable for a system you plan to keep.
The math shifts when you factor in repair avoidance. An older system that generates one $800 repair per year in addition to efficiency losses is losing $1,200 to $1,400 annually compared to a new system. At that rate, a $9,000 replacement pays for itself in 6 to 7 years.
If you are ready to explore what a new system would cost for your home, our AC installation page covers current equipment options and our process. For those concerned about upfront cost, financing options are available that let you pay monthly rather than all at once.
Heating Systems: The Often-Overlooked Half of the Decision
Most of these conversations in Las Vegas focus on cooling, and understandably so — but furnaces and heat pumps are part of the same repair-versus-replace analysis, and they interact. If you are replacing an aging air conditioner, the moment to also evaluate your furnace or air handler is now, not in three years when the next component fails.
Gas furnaces in Las Vegas typically run fewer than 500 hours per year versus 2,500+ for cooling. That light load means a well-maintained furnace can last 18 to 22 years. But age still matters: a 20-year-old furnace with a cracked heat exchanger is a safety issue, not just an efficiency issue, and replacement is non-negotiable. Any time a technician mentions a cracked heat exchanger, that is the end of the repair conversation.
For homeowners considering a full system overhaul, pairing a high-efficiency heat pump with a gas furnace as a dual-fuel system is an increasingly popular option in Las Vegas. The heat pump handles mild-weather heating efficiently, and the gas furnace takes over when temperatures drop below 35°F (which does happen in December and January in the Valley). Our heating services page walks through the options in more detail.
If you are on a maintenance plan, your technician is already evaluating both heating and cooling components at each visit — which is the best early-warning system available for avoiding surprise failures.
Making the Decision: A Practical Checklist
Run through this before you call anyone:
- How old is the system? Find the manufacture date on the data plate, not the installation date.
- What is the repair quote? Get it in writing with a clear description of what is being replaced and why.
- What would full replacement cost? A ballpark from our HVAC services page or a quick call to our office gives you a comparison point.
- Apply the $5,000 rule: Age × repair cost. Over $5,000? Lean toward replacement.
- Apply the 50% rule: Repair cost ÷ replacement cost. Over 50%? Replace.
- What is the repair history? One repair in five years is normal. Three repairs in two years is a system in decline.
- Is the refrigerant R-22? If yes, factor in the scarcity premium on refrigerant for future service — it adds meaningfully to every repair going forward.
- How long do you plan to stay? If you are selling in 18 months, a smaller repair may be the right call even on an older system. A new system does improve resale value, but payback through the sale price is not always dollar-for-dollar.
- Are there efficiency rebates available? NV Energy periodically offers rebates on high-efficiency equipment that can reduce replacement cost by $300 to $700.
Frequently Asked Questions
What is the 50% rule for HVAC repair vs. replacement?
The 50% rule states that if a repair costs more than 50% of what a new system would cost, replacement is generally the better financial decision. In Las Vegas, a full HVAC replacement runs $6,000 to $15,000 depending on system size and scope, so repairs exceeding $3,000 to $7,500 typically trigger a serious replacement conversation. The rule exists because a costly repair on an aging system does not reset the system's age — it simply buys time on equipment that is likely to need another repair soon.
How long do HVAC systems actually last in Las Vegas?
Air conditioners in Las Vegas realistically last 12 to 15 years under normal maintenance — shorter than the 15 to 20 year national average, because our systems log 2,500+ runtime hours annually and operate in extreme heat. Attic-installed systems face additional stress from ambient temperatures reaching 150°F, which accelerates wear on capacitors, contactors, and refrigerant lines. Gas furnaces last longer here, often 18 to 22 years, because heating season is short. Heat pumps, which run year-round, typically fall in the 12 to 15 year range.
Is it worth replacing a 10-year-old HVAC system in Las Vegas?
It depends on the repair cost and the system's condition. Apply the $5,000 rule: 10 years × repair cost. If the product exceeds $5,000, replacement deserves serious consideration. A 10-year-old system that has been well-maintained, uses current R-410A refrigerant, and needs only a moderate repair ($400 to $600) is probably worth keeping. A 10-year-old system with a $2,000 compressor quote, corroded coils, and a history of recent repairs is a candidate for replacement — you would be investing significantly in equipment likely to fail again within 3 to 5 years.
Does a new HVAC system really save money on electricity in Las Vegas?
Yes, and the savings are more meaningful here than in most of the country. Because Las Vegas homes run cooling systems for 5 to 6 months at high intensity, efficiency gains compound quickly. Replacing a 13 SEER system with an 18 SEER2 system typically reduces cooling energy consumption by 25 to 35%. On a home spending $150 per month on cooling during peak months, that is $40 to $50 in monthly savings — roughly $400 to $600 per year. Over a 12-year system life, those savings partially or fully offset replacement cost, especially when combined with repair avoidance on the old system.
Should I replace my AC and furnace at the same time?
In many cases, yes — and this is a question we encourage homeowners to ask proactively. The indoor air handler (which houses the furnace or electric heat strips and the evaporator coil) is matched to the outdoor condenser for efficiency and compatibility. Installing a new high-efficiency condenser on an aging air handler often means you cannot achieve the system's rated SEER efficiency because the components were not designed together. If the furnace or air handler is within 3 to 5 years of end of life, replacing both at once saves you a second installation fee, ensures compatibility, and lets you coordinate any ductwork modifications in one project rather than two.
Ready to Make the Call? Talk to Our Team First.
The Cooling Company has been serving Las Vegas homeowners since 2011 with honest diagnostics and upfront pricing. When you call us for a repair-versus-replace evaluation, we give you both quotes side by side — repair cost, projected system life, and replacement cost with projected energy savings — so you can make a fully informed decision. No pressure, no upsell. Just the numbers.
Call us at (702) 567-0707 or explore our services below.