The air conditioner dies on the hottest afternoon of the year. A technician opens the outdoor unit and tells you the compressor has failed. The repair is one price, a new system is another, and the decision gets made badly without transparent pricing more often than it should.
There is a piece of arithmetic most homeowners never hear, and it settles most of these questions in about a minute.
What the arithmetic actually says
Multiply the age of your system in years by the cost of the repair you are considering. If that total is close to what a new system would cost you, replacement usually wins. If it is well under, the repair is usually worth doing. It is a starting point, not a verdict. Age alone never decides it.
Two examples anchor it. A system that is a few years old and has needed one repair. The total stays well under a replacement, so the repair is usually worth doing, and the system still has most of its life in front of it. A system that is old and has needed work every year. The total passes a replacement, so replacement usually wins, and a failure on an aging system also tends to be followed by others.
| The system | The arithmetic | What usually happens |
|---|---|---|
| A few years old, the first repair | Stays well under a replacement | Repair it |
| Middle aged, the second or third repair | Lands close to a replacement | Check the warranty, then the parts |
| Old, and it has needed work every year | Passes a replacement | Replace it |
The arithmetic compares one repair against one replacement and asks which one comes out ahead. It works from the numbers in front of you, the age from the data plate and the cost of the repair you are considering, so it is worth doing properly rather than guessing at it.
Three worked examples
The old system that needs work every year. The compressor has failed and the pattern says the next failure is not far behind this one. On the arithmetic alone, replacement wins, because keeping the old machine going over the years it has left costs more than a new one would cost you to put in. A compressor failure on an aging system also tends to be followed by others.
The system that is a few years old and has needed one repair. One clear fault on a system with most of its life left in front of it is a repair rather than a replacement. The total stays well under what a new system would cost, so the repair is usually worth doing. The same fault on a much older system moves the answer the other way, because the age and the cost of the repair are multiplied together and the total climbs with it.
The warranty case. A system that is a few years old, with parts coverage still on it, may not cost you anything for the repair at all. The arithmetic decides between repairing and replacing. It does not decide between paying and not paying.
Use the real numbers: the price on your estimate, the age from the data plate, and the last two years of repairs rather than only the last one.
Repair or replace: the decision list
The more items that point at replacement, the less the arithmetic matters.
- The system is more than 12 to 15 years old. Parts get harder to find and the efficiency you bought in year one is gone.
- You have called for repairs more than once in the last two years. One repair is maintenance. Repairs every year are a pattern.
- The bills keep going up. A system working harder for the same comfort costs more to run every year.
- The comfort in the house is uneven. Rooms that stay warm while others cool usually mean undersized ducts or a system that cycles.
- The fault is a design problem, not a wear problem. A system too large for the house, or ductwork that leaks, causes the same trouble with new equipment.
- It runs on an old refrigerant. R-22 is being phased out, so refrigerant is limited and parts get harder to find.
- Parts coverage has run out. A system with 10 year parts coverage still on it deserves a different calculation.
- The heat exchanger is cracked or the unit is badly corroded. That is a safety replacement, not an optional one.
And the other way round. Repair if the system is under 10 years old, the fault is small and clear, the warranty covers it, and the ductwork is sound.
Five questions to ask before you decide
- What exactly failed, and how do you know? You want a diagnosis, not a guess. If the technician cannot explain the fault in a sentence, ask what they will do to find out.
- How much is the repair, and how much is the replacement? Both in writing, with the ductwork line on each, because a replacement priced without ductwork is not a price.
- What does each warranty cover? Parts and labour, and how long each lasts.
- How old is the equipment, and when was it installed? The date is on the data plate, or on the original invoice.
- What happens if I do nothing and the fault comes back? A good contractor will tell you what the next failure is likely to cost.
What an honest second opinion is worth
If another company has told you to replace your system, we will look at it again and give you an honest second opinion. Here is what that is worth and what it is not.
It is worth something because the expensive part of a replacement decision is the diagnosis, not the equipment. A second opinion that ends with a specific fault, a specific repair price and a specific replacement price turns a stressful conversation into a comparison. It is worth most when the first recommendation arrived without a written quote, because the fault was never established.
It is worth nothing if it is another opinion without numbers. Ask for four things: the fault, the repair price, the replacement price with ductwork included, and the warranty on each. If you cannot get those four, you have a second opinion of the same guess.
RB was great, very informative, easy to talk with, up front about the process with all options available to us. Steve Chervony, Google review
What drives the price of a replacement
The factors to know before the conversation starts, and what a quote should itemise.
- System size, from 2 to 5 tons, set by a Manual J load calculation rather than by square footage, and it scales the equipment, the labour and the electrical work together.
- Efficiency rating, which decides how much equipment you are buying and how it performs year after year.
- The condition of the existing ductwork, which is worth addressing if the ducts are leaking, undersized or disconnected, and which decides what the new system can be sized to.
- The electrical scope, including any new circuit, sub-panel or service work the house needs.
- Access and install location, whether the unit goes on the roof, the side of the house, the attic or the ground, because the labour follows the access.
- Brand and efficiency tier, which is the choice with the widest spread in it and the one that is largely yours to make.
- 10 year manufacturer parts coverage, plus 1 to 5 years of labour from us on a replacement, and 5 years on an installation.
- Financing is available on qualifying credit.
- A military discount for active and veteran service members on a new system installation. Ask us about it.
- Rebate paperwork. We help customers get approved for California TECH Clean California rebates.
We size the equipment with a Manual J load calculation before anything is ordered, so it matches your house rather than a rule of thumb. We quote the exact price in writing before work begins, with transparent diagnostics and free phone guidance for installation planning. Nothing is added once the job has started.
When to stop and call a licensed technician
Either way, the work itself is not a do it yourself job.
- Any work on a refrigerant line, which has to be recovered and handled by a certified technician.
- Anything inside an electrical panel beyond resetting a breaker.
- Gas appliance work of any kind, including a pilot light that will not stay lit.
- A compressor, a blower motor or a heat exchanger, which are not homeowner components.
- Water near the unit, a burning smell or a hissing sound. Switch the system off rather than adjusting it.
- A replacement decision made on the spot without a written quote. A recommendation to replace a system needs a reason.
RB HVAC Inc. is a licensed HVAC contractor in Stockton, licensed in California under number 1094161, rated 4.9 across 215+ Google reviews. We work across Stockton, Sacramento, Modesto and surrounding communities, and we quote the price in writing before any work starts.
