Refrigerant leak detection & repair
If your system needs refrigerant,it has a leak.
Refrigerant is not fuel and it is not consumed. A sealed system that was charged correctly stays charged for its entire life. If yours is low, something is letting it out — and adding more without finding that is a repair nobody performed.
The thing nobody explains
Your AC does not use refrigerant up
An air conditioner is a closed loop. The same refrigerant circulates through the coils, changing between liquid and gas, over and over, for as long as the system lives. Nothing burns it, nothing consumes it, and a properly sealed system will never need more.
So when a technician tells you the system is "a little low on freon" and adds a pound or two, what has actually been established is that there is a hole somewhere. Refrigerant did not evaporate into thin air — it escaped into it.
"Low on refrigerant" is not a diagnosis. It is a symptom, and the diagnosis is where it went.
Why the annual top-off is such a bad deal
This is the industry's quietest recurring charge. It feels cheap each summer and it costs a great deal more than it looks.
You are buying the same thing repeatedly
Every top-off pays for refrigerant that will be outside your house again by next season. Over five or six years that adds up to more than locating and repairing the leak would have cost once.
The compressor is running starved the whole time
Refrigerant cools the compressor as well as your home. A system that spends every August low on charge runs its compressor hot and lean, and that is exactly the wear pattern that produces a four-figure failure three summers later.
It costs you on every PG&E bill
An undercharged system works harder for less cooling. You pay for the refrigerant, then you pay again every month in consumption while it slowly escapes.
The leak is getting worse, not staying put
Leaks do not hold steady. A pinhole that needed one pound this year will want two next year, and the interval between calls shortens until something fails outright.
It is going into the atmosphere
Refrigerants are regulated for a reason and technicians handling them are required to be EPA certified. Knowingly recharging a leaking system year after year without repair is not a defensible practice, whatever the invoice says.
Our position is simple: we will not top off a leaking system and send you an invoice as though something was fixed. We locate the leak, tell you what repairing it costs, and if the honest answer is that the system is not worth repairing, we tell you that too.
How a leak is actually located
Four methods, used together. A gauge reading tells you the system is low; none of these can be skipped if you want to know where from.
Electronic leak detection
A calibrated detector traced slowly along the coils, joints, fittings and line set. Sensitive enough to find leaks far too small to see, and it is the workhorse of the process.
Bubble solution
Applied to accessible joints, valves and service ports. Unglamorous, cheap and remarkably effective at finding exactly the leaks that get overlooked in favor of expensive answers.
Nitrogen pressure test
The system is pressurised with dry nitrogen and watched for pressure decay. This is how slow and intermittent leaks get caught — the ones that will not reveal themselves under normal running pressure.
Visual and oil trace evidence
Escaping refrigerant carries compressor oil with it, leaving residue at the leak point. Oil staining on a coil face, a fitting or in the drain pan is often the fastest clue there is.
Where leaks usually are
Ranked roughly by how cheap they are to put right, which is also roughly the order they should be checked.
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Cheap fix
Service valve cores and caps
Schrader cores wear and seep, exactly like a tire valve. Frequently the entire problem, and among the cheapest repairs in HVAC. Always worth checking before anything expensive is proposed.
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Cheap fix
Flare fittings and connections
Common at the outdoor unit and on mini-split installations. Often just needs correcting and resealing rather than replacing anything.
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Moderate
Brazed joints on the line set
A joint that was marginal from a previous repair or from the original install can open under years of thermal cycling. Usually repairable in place once located.
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Moderate
The condenser coil
Outdoor coils take physical damage and corrode, particularly in dusty valley conditions. Repairable in some cases, replaceable in others, and generally less expensive than the indoor coil.
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Expensive
The evaporator coil
The expensive one, and the most commonly blamed. Formicary corrosion produces microscopic pinholes throughout the tubing that cannot be spot-repaired. More on coil replacement.
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Expensive
The compressor body or fittings
Least common, and the most serious. A leak at the compressor itself usually means the compressor is being replaced rather than repaired.
Which refrigerant is in your system
It is printed on the data plate of your outdoor unit, and it changes the economics of a leak repair more than almost anything else.
R-22
Older systems, generally pre-2010
Production and import into the United States ended in 2020, so the only supply left is reclaimed material. Prices reflect that scarcity, and a system that needs several pounds becomes expensive quickly.
On a leak: component and electrical repairs are still worth doing at almost any age. A significant refrigerant leak usually pushes the decision toward replacement, because the refrigerant itself has become the costly part.
R-410A
Roughly the last fifteen years
The long-standing standard for residential equipment. It is being phased down for use in newly manufactured systems under federal rules, but existing R-410A equipment can still be serviced and recharged normally.
On a leak: repairs remain entirely practical. Supply is available and the economics of finding and fixing the leak are straightforward.
R-454B and other low-GWP blends
New equipment
What new residential systems now ship with, chosen for much lower global warming potential. These are A2L refrigerants, classified as mildly flammable, which means specific handling, detection equipment and technician training.
On a leak: serviceable as normal, but only by a company properly trained and equipped for A2L refrigerants. Worth confirming before anyone opens the system.
If you have R-410A, you have not been made obsolete
A sales line doing the rounds right now suggests that R-410A systems are finished and should be replaced immediately. That is not what the phasedown means. The rules govern refrigerant used in newly manufactured equipment — your existing system can still be serviced, repaired and recharged.
Supply will tighten gradually over years, and that is a fair thing to factor into a replacement decision when the time comes. It is not a reason to replace a healthy system this summer, and anyone telling you otherwise is selling rather than advising.
Where we stand
We do not use injected leak sealants
Sealant products are sold as a cheap alternative to finding the leak. They are injected into the system in the hope of plugging a hole from the inside, and they occasionally work on a very small leak.
They also circulate through the entire sealed system, and they do not distinguish between the hole you want blocked and the metering device, the compressor, or a service technician's recovery equipment.
We would rather spend the hour finding the leak. If the honest conclusion is that the system is not worth repairing, we will tell you that instead of buying you a season with something that makes the next repair worse.
Why we avoid them
- They can foul the metering device and restrict the system
- They can contaminate recovery and recycling equipment, which is why many shops refuse to service a treated system
- They mask the leak rather than fix it, so nobody learns where it actually was
- Manufacturers commonly warn against them, which can complicate a warranty claim
What it costs
The range is wide because the leaks are
A worn valve core and a leaking evaporator coil are both "a refrigerant leak" and they are not remotely the same job. That is why we locate it before quoting rather than pricing the worst case in advance.
Refrigerant type moves the total, since replacing what escaped costs very differently on R-22 than on newer refrigerants. Coil and compressor leaks are quoted separately because they are component replacements rather than leak repairs.
Refrigerant questions
Why does my AC need refrigerant every year?
Because it has a leak. Refrigerant circulates in a sealed loop and is never consumed, so a system that was charged correctly should never need topping up. Annual recharging without leak repair means you are paying repeatedly for refrigerant that escapes into the atmosphere while the compressor runs starved.
How much does refrigerant leak repair cost in Fresno?
Typically $400 to $1,600 depending on where the leak is and which refrigerant the system uses. A worn service valve core is at the low end. A leaking evaporator coil or compressor is quoted as a component replacement rather than a leak repair. See published repair ranges.
Can you just add refrigerant to get me through the summer?
We will be straight with you about what that does. Where a leak is small and you are planning a replacement anyway, a controlled recharge can be a reasonable bridge and we will say so. What we will not do is bill it as a repair, or do it repeatedly year after year while the compressor runs low on charge.
Is R-410A being banned?
Not for servicing existing equipment. Federal rules govern the refrigerant used in newly manufactured systems, which is why new equipment now ships on lower-GWP refrigerants such as R-454B. Your existing R-410A system can still be serviced, repaired and recharged. Supply will tighten gradually over years, which is worth factoring into a future replacement decision but is not a reason to replace a healthy system now.
What is R-454B and does it change anything for me?
It is one of the low global warming potential refrigerants that new residential systems now use. It is classified A2L, meaning mildly flammable, which requires specific handling, leak detection equipment and technician training. If you are having new equipment installed, it is fair to ask whether the company is trained and equipped for A2L refrigerants.
How long does leak detection take?
Usually an hour or two. An accessible leak at a fitting can be found quickly. A slow leak inside an indoor coil in an attic takes considerably longer, and may require a nitrogen pressure test to confirm. It takes as long as it takes, which is precisely why some companies would rather add a pound and leave.
Is a refrigerant leak dangerous?
Residential refrigerant leaks are not usually a household safety hazard, though they should not be inhaled deliberately and leaks in confined spaces deserve ventilation. The greater risks are to your compressor, your electric bill and the environment. Never attempt to add refrigerant yourself — handling it legally requires EPA certification.
Find the leak, not just the symptom
Proper detection, a straight answer on whether it is worth repairing, and a price before anything happens.
Prices shown are typical ranges for the Fresno area and are not quotes. Refrigerant handling requires EPA Section 608 certification. California Heating & AC Repair is operated by Craftline Renovations, Inc. · CSLB License #999179 · Licensed and insured.