Table of Contents
- This article will instruct you on the top reasons and places in the HVAC system for refrigerant leaks. Some people say Freon® leaks.
- What happens when an air conditioner or heat pump has a low refrigerant charge as a result of a refrigerant leak. How a refrigerant leak affects your AC system.
- What you will see or experience with your heating and air conditioning HVAC system if you have a refrigerant leak.
- Why HVAC Contractors do not provide warranties for refrigerant leaks for heating and air systems.
- Making the decision to repair the leak or replace the system.
- Basic air conditioning repair and heat pump repair. How repairing a leak will take your system from low efficiency to high efficiency. This can also apply to a mini-split or ductless system.
- Differences between new refrigerants and old refrigerants.
- Plenty of in-depth related links that will allow you to understand the subject better.
HVAC Refrigerant Leaks | Air Conditioner Leaking Freon® - R410A - R22
New Clean Evaporator Coil for a Heat Pump
Top Reasons for AC Freon® Refrigerant Leaks – Air Conditioner Refrigerant Gas Leaks – Air Conditioning Refrigerant Leaks –
HVAC Refrigerant Leaks
There comes a day when the air conditioner stops cooling and you call your local HVAC contractor or air conditioning contractor for air conditioner service and repair. Your air conditioner is blowing hot air. Do you have an Air Conditioner Refrigerant Leak? The HVAC service technician arrives and checks the filter and some other things. You see him go to his truck and get some tools and a set of gauges while you hope for the best. Ten minutes later he comes back to report to you that your air conditioning unit is low on refrigerant.
Now comes the time when you need to understand why the air conditioner needs refrigerant and what to do next? Will this involve repairing a leak or getting a new heating and cooling system? You need air conditioner repair to fix the leak. The HVAC contractor specializes in repairing freon leaks so your AC won’t blow warm air.
Air Conditioners and Heat Pumps | HVAC Refrigerant Leaks
First of all the air conditioner or heat pump (if you have a heat pump) does not consume Freon or refrigerant. The system is a sealed system and the air conditioner does not burn or use up refrigerant to make your house cool. Cool and heat your home if you have a heat pump. Therefore, it should never have to be filled up unless a leak occurs in the system. Heating and air conditioning systems are supposed to be sealed but leaks do happen.
How, Why, and Where? HVAC Refrigerant Leaks
From time to time a leak occurs in the air conditioning system and the unit needs to be charged. A correct and precise charge is important so that it can continue doing its job of cooling the home. As the refrigerant leaks out, the system still cools. It cools too much. The indoor evaporator coil begins to freeze up because the temperature of the evaporator coil drops below the dew point.
That is humidity or moisture in your home or business, which passes through the air conditioning (or heat pump) indoor coil (evaporator) for conditioning. The refrigerant in your air conditioner is supposed to be locked in a hermetic system and sealed tight.
Signs of a Leak in an Air Conditioner or Heat Pump | HVAC Refrigerant Leaks
A leak causes ice to form on the coil and other parts of the air conditioner. Ice buildup on your AC stops it from cooling. The air conditioning system experiences a reduced amount of airflow because of the coil ice buildup. You may notice ice on the copper refrigeration lines, which run to the outside condenser.
If you see this, it is important to shut the system off immediately and call your HVAC service company. If the system is left running, the indoor evaporator coil will turn into a block of ice, and no airflow will come out of the vents. Reduced airflow is a symptom of a refrigerant leak.
Related Link: On a refrigerant temperature-pressure relationship chart or PT chart the less refrigerant in the system the colder the system. When the temperature of the coil drops below freezing, the moisture in the air freezes to the coil. (link opens in a new window)
Your vehicle typically uses R-134A, which is different than what is in-home air conditioners and heat pumps. Technically, it is inaccurate to refer to refrigerant as Freon®. Freon® is a name used to describe R-22 made by Chemours (Dupont spin-off). R-22 is currently being phased out with the final phase-out date set for 2020.
Air Conditioner Leaking Freon® - Causes of Refrigerant Leaks - HVAC Refrigerant Leaks
The most likely leaks for a central air conditioner system can be anywhere and caused by various things. Air conditioning units, as well as heat pumps, are mechanical systems with moving parts. Here are the reasons why your air conditioner has a Freon or refrigerant leak:
The bubbles indicate a leak
- Leaking Shrader Valve
- Heat Pump Accumulator Leak
- Capillary Tube Leak
- Flare Connections
- Evaporator or Condenser Coils
- Filter Dryers
- Line Set
1
Leaking Shrader Valve | HVAC Refrigerant Leaks
A Shrader valve is leaking Freon and needs to be replaced. There is a tool that can be used to change this Shrader valve without having to recover the entire amount of refrigerant from the system.
These Shrader valves look like the little valves in your car tire. They hold the refrigerant in the system and allow the technician to access the system to test the pressures or to charge the system if necessary. These Shrader valves are necessary, and sometimes the rubber seals deteriorate, or the Shrader valve gets stuck and allows Freon or refrigerant to leak out of the air conditioner system.
Shrader valves are located in or near the condenser unit but can also be in the indoor unit, the air handler. Consider yourself lucky because this problem repaired easily.
2
Heat Pump Accumulator Leak | HVAC Refrigerant Leaks
If you have a heat pump heat pumps have accumulators. Accumulators are necessary for the heat pump system to provide heat in the winter and protect the compressor from liquid slugging. Accumulators are steel, and after a few years, they begin to rust.
These rust holes allow Freon or refrigerant to leak out of the heat pump system. The heat pump accumulator replacement is possible, but the recovery of the refrigerant is necessary, and a new accumulator installed.
The new accumulators sold on the market today are also made of steel and will eventually leak after rusting occurs in the future. It is hard to say what the average life expectancy of an accumulator is and depends on the quality of steel used to make the accumulator, so the time varies on when the accumulator will leak.
To prevent this from occurring in the future with a new accumulator or new heat pump it is not a bad idea to spray the accumulator with some rust preventing paint upon discovery of a rusty accumulator on an air conditioning preventive maintenance check.
Performing a Leak Refrigerant Leak Test
3
Capillary Tube Leak
A capillary tube is leaking on the inside evaporator coil or if you have a heat pump on the outside heat pump condensing unit. These capillary tubes are tiny copper tubes, and over time and through the vibration of the system, they rub together or rub against another piece of metal.
A hole appears on the capillary tube, and Freon or refrigerant leaks from the air conditioning or heat pump system. These leaks can be difficult to find because disassembly of the system is necessary to find the leaking capillary tube.
Upon discovery of a leak, a cut is made in the capillary tube, the hole for the capillary tube reamed, and another larger piece of copper tubing soldered over the capillary tube.
This does not apply to capillary tubes which connect metering devices to thermostatic expansion valve (TXV) bulbs. These damaged TXVs need to be replaced and do not contribute to leaking Freon from the system.
4
Flare Connections
If the air conditioning or heat pump system has any flare connections, leaks generally occur at these connections. Sometimes these flare connections can easily be repaired while other times the flare fitting and connection have to be replaced and remade completely to prevent future leaks in your AC unit.
5
Evaporator or Condenser Coils | HVAC Refrigerant Leaks
The indoor or outdoor air conditioning or heat pump coil is leaking and needs repair or replacement. Most of the time, the leaks in the coils (whether they be outside or inside coils for an air conditioning or heat pump system) occur at the u-tubes. These are bends in copper at the end of the coil.
There is a tube sheet made of sheet metal that holds the coils together, and over time, and through vibration, the u-tube part of the coil rubs against the tube sheet, and a refrigerant leak occurs. Sometimes this can be easily repaired, but other times, replacing the coil is necessary. Depending on the age of the unit, indoor and outdoor coils are available for replacement.
The problem with leaks near the tube sheet is when the technician uses heat to repair the leak in the coil, the heat loosens other parts of the coils, and another leak could occur. It will take a very good technician who knows how to braze very well in order to repair this type of refrigerant leak.
6
Filter Dryers
Filter dryers are installed in all refrigeration systems. They are necessary for absorbing minute amounts of moisture in the system and for filtering trash before it gets to key components, which could be damaged or plugged if the trash was allowed to get to the components. These filter dryers have screens and desiccant inside them and the steel outer shell.
The same problem that occurs with a heat pump accumulator will eventually occur with a filter dryer, and a refrigerant leak occurs. Replacing the filter dryers is easy but only after recovering the entire amount of refrigerant or pumping the entire amount of refrigerant contained in the air conditioner or heat pump system into the condenser using the pump down method.
7
Line Set
The line set which carries refrigerant back and forth from the condenser to the evaporator coil has been pierced or damaged. Damage can occur from a lawnmower or someone tripping over the line set. Additionally, line sets generally run in voids inside walls and ceilings just below the roof.
I once had a line set that was pierced by a nail on a roof repair. The refrigerant took a year to leak out before the air conditioner was no longer functional and the customer required an HVAC professional to troubleshoot and repair the air conditioner system.
Refrigerant Leaks Final Advice - Air Conditioner Leaking Refrigerant
R-22 Refrigerant and Recovery Tank
That covers the major types of HVAC refrigerant leaks which occur with air conditioner and heat pump systems.
Depending on the age of the air conditioner or heat pump system and the type of refrigerant leak which occurs may determine whether or not you decide to replace the air conditioner or heat pump system.
Many air conditioning and heating service and repair companies will not provide a warranty for refrigerant leak repairs.
Because it is possible to repair one refrigerant leak and have another refrigerant leak occur in a different location.
It is a decision you must make by weighing the cost of the repairs versus the age of the equipment versus the cost of installing a new coil or air conditioning or heat pump system.
If the unit is old and has caused many problems, the decision may be easy, but it is a big decision, so take time and weigh it carefully.
Related Links | HVAC Refrigerant Leaks
Heat Pump Low on Refrigerant - Heat pumps are not immune to refrigerant leaks. Find out how to tell if your heat pump needs refrigerant.
(links open in a new window)
Refrigerant Leak Advisory | Health and Refrigerant Smell
Additionally, caution advised when around refrigerant chemicals, including the oil in the refrigerant, that lubricates the system. Newer refrigerant oils such as the POE’s or Polyol Ester Oil used in HFC refrigerants will absorb moisture, including the moisture in your skin, causing a burn. Furthermore, if your system is leaking refrigerant, it is almost assured that there is oil near the leak area.
The smell of refrigerant is nearly odorless. There is a slight chemical smell to most refrigerants. If you are a technician, be aware when brazing. When refrigerant burns, it turns green. That is phosgene gas, and it is very severe for your health. Avoid breathing it. The refrigerant in HVAC and automotive systems are asphyxiants. Too much will in a small area will take your oxygen away.
Most homeowners do not have to worry about this problem. If you are a technician and working on larger systems in a small mechanical room, a large volume of refrigerant can overcome you.
Maintenance
Make sure whether you have an older central air conditioning system or even a new air conditioning system, an air conditioning service provider for air conditioning maintenance. Heating and cooling systems, as noted above, are mechanical systems with lots of moving parts. It’s a good idea to have an expert check out your air conditioning equipment to make sure it is running optimally.
They can give your system a tune-up and find any problems that can result in a potential catastrophe in the future. Leak repair will increase your SEER rating, which will decrease your utility bills. Air conditioner repair of a leaky system will also give you better home comfort.
Conclusion | Refrigerant Leaks | Leaking Freon
Additionally, preventive maintenance can spot potential problems. Preventive maintenance can prevent expensive air conditioning repair bills. AC units have lots of moving parts and electrical and mechanical processes and need regular maintenance. AC maintenance can prevent AC freon leaks. It can also reduce your electric bills and keep your central AC running reliably.
HVAC Refrigerant Leaks – Leaking Freon
Technical Resource: Refrigeration and Air Conditioning Technology
It’s a pity you don’t have a donate button! I’d most certainly donate to this brilliant blog! I suppose for now i’ll settle for book-marking and adding your RSS feed to my Google account. I look forward to brand new updates and will talk about this site with my Facebook group. Chat soon!
I have mostly the same issues as in the comments that “Jude on March 26, 2021” wrote about. My unit is a Carrier 12,000 btu ductless style unit with a heat pump & it seemed to work fine the 1st summer/ early fall season after being installed in May. Startup the following season the unit was not cooling, service technician tested unit and said the coolant was low. It required 2lbs of coolant to recharge the unit which was now just past the 1yr install warranty. Paid the service call and coolant cost and unit worked fine for that season. Spoke with customer service manager & they agreed to refund the coolant cost.Turned unit on again the following April only to find it was not cooling again. The same service technician returned again to check unit and says it needs 2lbs of coolant to recharge again. Also says it’s leaking from the bottom coolant fitting on unit which now requires replacement parts to the tune of $400. Not quite sure how this happens when this unit is is not very old & is off the ground mounted on the back wall of my house which is never disturbed. All I can figure is improper installation of this fitting when it was 1st installed & the next season when it had to be recharged? Will be contacting the customer service billing manager again to discuss this issue & hopefully negotiate this cost down.Thanks!
When I turn my air conditioner on, as soon as it starts getting warm, my air conditioner (AC) does not work. I call a technician to check it out and repair it, and he finds the refrigerant (Freon) is low. So he tops it up and the AC works for the entire summer and early fall. When winter comes, it is no longer in use. Then when it starts getting warm the next year, I find the AC is not working again. The technician checks it out and says the refrigerant is low again, and has to top it up again. Again, the AC works for the entire summer and early fall, and the next year we find that the refrigerant is low again. This has happened for the last 3 years, with the technician using some sealant to plug any leaks. But this year the AC is not working again. I suspect that the refrigerant has leaked again, but will know once the technician confirms it. My question is: what is the nature of the leak, and from where do you think the leak is coming if the AC works for about 9 months without losing refrigerant but then starts leaking refrigerant when it is not in use for about 3 months or so. My technician seems to think that if the leak occurs when the AC is in use, the leak is somewhere in the top where the vents are, and if the leak is occurring when the AC is switched off, the refrigerant settles, and the leak is somewhere at the bottom, in the AC unit. Could this possibly be the case? And how can I find and fix the leak once for all, without having to pay and fill refrigerant every year. Thanks!
You have a small leak somewhere. It is not uncommon. Hire a new tech that will find the leak if the old one (tech) can’t find the leak.
Have you heard of installers not following manufacturers’ (both mini-splits equipment AND line sets) installation requirements, then customer has a failure and/or leak? Have these been proven and tracked by either a consumer protection agency (state or fed) or industry service organization? Professional membership org?
Lots of these questions. It’s why we always recommend you purchase equipment and services from vet reliable contractors. Someone who stands behind their workmanship and the product they sell.
We have a condenser coil failure in a Rheem heat pump newly installed in 2017. The leak is visible from a 5 inch oil patch seen on the bottom of the coil. My question is should we replace the coil, getting quotes from $1500 and up, knowing that Rheem coils are known to fail, or should we upgrade the condenser to a more reliable brand?
It should be covered by warranty. I know that isn’t helpful right now because you still have to pay for labor but I’d likely go for the new coil rather than a new system. I would also make sure I got a warranty on the work and the new coil.
I didn’t know that a leak can cause ice to form around your air conditioner’s components and reduces airflow. My wife and I have noticed that our living room hasn’t been getting cool recently, and we are worried that it may have something to do with the puddle that has been forming under the unit. Maybe we should consider hiring an expert to repair our AC.
I have a 12 year heat/ac unit. Service personnel just told me there is no FREON. Doesn’t know where the leak is. Cost $100/lb (7 lbs).
He doesn’t guarantee finding the leak and the work to locate would be expensive plus if the leak is inside he suggests replacement. Replacement cost with Amer Std 4 ton 16 seer plain AC (no heat) is$6,100.
is the replacement cost reasonable
Sounds like a good ballpark (always get at least three quotes from separate contractors for major repairs or replacement) and finding a leak in an old system is never guaranteed at least by myself or any contractor I ever worked for. And the cost can be reduced for replacing the refrigerant by using a drop-in refrigerant. R-22 is no longer manufactured so it is expensive but there are drop-in replacements for it that are cheaper.
If you have a heat pump I would check the accumulator for leaks. They are made out of steel and rust through. Its a common problem and 12 years is about right for a heat pump.
The unit in the house has a r22 condenser and a r410 evaporator coil. There is a leak in the evaporator coil. The cost to replace the coil is about $1300 (with installation). Trane will not provide any warranty on the coil. My HVAC company will provide a 1 year warranty. They also suggested that I should consider replacing the entire system. The inside unit is 8 years old and the condenser is older. We purchased the house 5 years ago. I should also mention that we had a hot water heater leak. The inisde unit was drenched with water for an unknown amount of time before the leak was discovered. Not sure which way to proceed. Could the inisde unit be so damaged from the water that it is not worth just replacing the coil? What about the r22 condenser and r410 evaoprator working together? Is that efficient? Is that a problem in the long run? Any input would be appreciated.
Either replace the coil only and continue with R-22 or replace the entire system? I would say replace it from a consumer perspective for efficiency reasons. You will likely notice a reduction in your electric bill plus get a fully warranty with the new system. Make sure to read up on HVAC warranties. And no, you can’t mix and match with R-22 and R-410A. It has to be either one or the other.
Need help please. I have a Fujitsu mini split with 3 heads installed May, 2019. I live in Chicago, so that means the unit was only running for 3 months. I turn the system on this season and no cold air. Repairman wants to do a leak test and gave me an estimate of $2,300! Is this reasonable? My 1 bedroom condo (1,000 sq ft) on top floor has the condenser on roof, just above my unit. Am I getting ripped off?
Call for a second opinion. Don’t pay a flat rate until you know where the leak is. In mini-splits, many leaks are found around the flare fittings or Schraeder/king valves. Always get a second opinion or even a third opinion. 2300 $ seems very high.
i have split mini with Leak?? 1st tech did Nitro test and had no leaks. The unit is year and half years old. Its a Senville, unit installed in winter, the next spring unit did not cool, new Tech found a leak at flared fitting done by old hvac guys, new Tech repaired with new flare and gasket. next winter unit worked fine and heated then came spring. Unit would not cool and new tech said low on Freon added 1.7 lbs. Tech said maybe leak?? only other flared fitting was factory flared fitting at unit in attic, no oil, and bubble test shows no leak?? any idea on problem?? What do you think? manufacture says to do another Nitro test. Tech says this might not show a small slow leak??
the tech is correct. Only thing I could recommend is ultraviolet dye injection or just fill it up whenever it stops working.
Got a new system (Goodman) in April 2018, it stopped working 2 weeks ago, I called the technician, he found that there is no freon in the system, so there is a leak some where. He charged 5# of refrigerant. It was running good for 2 weeks and quits again. It did not freeze the evaporator coil. He said, there may be a leak in the line set since he could not find the leak anywhere in the evaporator coil or outside unit. Then he did dye test, could not find any leak. While adding the freon for dye test, he opened the refrigerant line and it sprayed water out of it, it looks wired. Is it possible that there is leak in the line set which is running inside the wall in a condominium?
Yes. I’ve found many leaks in line sets usually from poor workmanship when the HVAC unit was installed or because a sharp object pierced it. In the case of poor workmanship, the AC installation company should be offering you a warranty of at least one year for a new installation for the repair service. This should be the case on any HVAC repair for a new system including leakage of refrigerant due to poor workmanship. That warranty, if you have one, should include a repair and recharge of the air conditioning installation (or heat pump). If the refrigerant line set was accidentally damaged then that’s on you or whoever pierced it.
I’ve never used dye before. I’ve always used the high-pressure nitrogen with soap bubbles or trace refrigerant in the nitrogen and a refrigerant leak detector. My success rate using those methods is pretty good at finding and fixing leaks in AC systems – or heat pumps.
We have a Trane unit, that is still within warranty (a 10yr parts and labor warranty). When it stopped cooling, the technician came out, and replaced a part, but then charged us for 3# refrigerant, the company states that “refrigerant is NEVER covered by warranty”. Is this true or are we being duped? We have had warranty work on our other unit (Maytag), and the other company’s warranty DID cover the refrigerant.
not sure, you have to read the contract.
I just had our units get a freon charge last week-we noticed our main floor a/c is now not cooling. I went outside to inspect the unit and noticed two caps just laying on the ground next to where they should have been replaced after the charge-will all of that gas have leaked out? Or do you suspect another problem? (that unit was working fine until the charge-we originally called about the unit that cools the upstairs and while the tech was here he checked the other two units(we have 3) and gave the main floor one a charge as well. Thank you.
Those caps are for the access ports on the unit. More than likely the tech simply forgot to put them back on when he was finished. Many of the caps are made of plastic and would stop refrigerant from leaking anyhow. Rather, they prevent dirt, debris, and moisture from getting inside the valve which is like a valve on your car tire. The car tire does not lose air if you forget to put the cap back on. There are times when those valves will leak and the only way to stop the leak is to replace the valve or use a brass cap instead of a plastic cap. There is a special tool to replace those valves in case they leak. If you do not have the tool the entire system needs to be recovered (refrigerant recovery) and then the valve replaced and then the refrigerant returned to the system.
I would go ahead and put the caps back on or if you are not comfortable doing it call the service company back and get the tech to return and put them back on. It will likely be embarrassing to him but it could be a lesson for him to never forget to replace those caps when he is finished with the job.