Air conditioning, heat pump or refrigerator / freezer refrigerant gas or liquid leaks: How do we repair refrigerant leaks in air conditioning, heat pump, or other refrigeration systems? This article series discusses how to repair refrigerant leaks in air conditioning and cooling systems, using as an example, repairing a leaky or damaged air conditioning the cooling coil (evaporator coil) in the air conditioning air handler unit. Our photo at page top shows the cooling coil in the attic air handler component of a central air conditioning system. If your air conditioning or heat pump system has lost its cooling capacity or won't start see REPAIR GUIDE for AIR CONDITIONERS. As we explain in our articles on lost cooling capacity or air conditioning systems or heat pumps that are not working, a refrigerant leak in your air conditioner or heat pump means that eventually it will just not produce cool air (during air conditioning) nor warm air (during heating if it's also a heat pump).

First we need an accurate diagnosis of the air conditioning problem. If your air conditioning or heat pump system has lost cooling (or heating) capacity, there can be various causes besides loss of the refrigerant in the system. As we also introduce at CONDENSING COIL REPAIR REPLACE, there is a big payoff in cleaning dust, debris, grass clippings off of a dirty refrigeration condensing coil (this includes outdoor condenser/compressor units for air conditioners and heat pumps and also the condensing coil on a home refrigerator or freezer). Because a refrigeration system works by transferring heat from hot refrigeration gas/liquid to ambient air around the condensing coil, if the condenser coil is blocked by dirt and debris, this can prevent complete cooling of the high temperature refrigerant gas back to a liquid state. The result is you'll get refrigerant gas bubbles passing through the refrigerant metering valve. On refrigeration systems that include a sight glass you can actually see these gas bubbles passing through the system.

More details are at REFRIGERANT SIGHT GLASS. Gas bubbles in the liquid refrigerant line can result in complaints of running water, gurgling, burbling, or similar sounds coming from the refrigerant piping system. See REFRIGERANT PIPING GURGLING. Watch out: Incidentally a second source of bubbling sounds heard in the refrigerant piping suction line near the compressor could be refrigerant oil pooling in that location.window ac unit diagram This oil pooling is not usually a consequential problem provided the collection of oil does not block passage of refrigerant in the system. how to fix a carrier ac unitIn good HVACR design the refrigerant piping slopes back from the evaporator unit (cooling unit or air handler) towards the compressor/condenser unit so that refrigerant oil in the line finds its way back to the compressor motor.ac unit water sensor

At HVAC school we were taught that some HVAC technicians, in the opinion of the instructor (and our own as well), like the idea of a "delivery route" business, coming around periodically to replace lost refrigerant. In our view in many circumstances this can be a questionable practice. Air conditioners and heat pumps are designed as a closed, hermetically sealed system - they are not supposed to leak refrigerant, and refrigerant leaks are an abnormal condition. The refrigerant leak can be found and repaired. If the technician was in a hurry, perhaps given many service call assignments, or if s/he didn't want to be hassled by a customer complaining over an "attempt convert a simple recharge to a costly service call", or if the company just likes to deliver refrigerant (lots of repeat business), or finally, if the system with the refrigerant leak is large, commercial, complex, and old - at end of life, s/he may not have mentioned that refrigerant leak repair is even possible.

If you are faced with a costly service call or repair on an old air conditioning system (such as the need to replace a corroded, leaky evaporator coil) on a system that is at or near end of life, it is understandable that you might just prefer to wait and replace the whole system. But it is not air conditioner or heat pump system age that makes a refrigerant leak able to be found or not, it is system complexity. Sometimes, especially with large complex commercial systems, because tracing all of the piping and tubing and looking for leaks is time consuming, some people opt to just add refrigerant. Just adding refrigerant is not the best practice. And with old freon-based cooling or heat pump systems such leaks might be illegal as you are damaging the environment and making a prohibited release of Freon gases to the air. The refrigerant gauge set photo above is discussed in detail at GAUGE, REFRIGERATION PRESSURE TEST. A step by step example of adding refrigerant to an air conditioning system using a rather minimalist approach is illustrated

at SPLIT SYSTEM AC / HEAT PUMP REPAIRS. Sorry to ask readers to click again but for more space we have moved this topic to REFRIGERANT LEAK SEALANT USE "Stop leak" products have been in use for decades, particularly in the automotive industry where they were used to address leaks in automotive cooling systems. Those products traditionally used a carrier and fibers (originally asbestos) - an approach not suitable for refrigeration systems whose refrigerant metering devices may not tolerate particulates, even small ones. Since the 1980's several inventors (e.g. Packo & Bailey 1980, 1982, 1984) have patented other approaches (and chemistry) for sealing small leaks in refrigeration systems. Some of these refrigerant leak sealant products use triethoxyl (vinyl) silane that forms a seal when exposed to air and can seal small openings in refrigeration systems without clogging up the capillary tube or thermostatic expansion valve. This discussion has moved to COOLING / EVAPORATOR COIL REPAIR

I f an evaporator coil is leaking (or also if the condensing coil is leaking) you'll find out pretty quickly as refrigerant will be lost and the cooling system will stop providing cool air. You'll need expert diagnosis by an HVAC service technician. Sketch at left courtesy of Carson Dunlop Associates. For an example of coil replacement costs see our condensing coil replacement discussion at CONDENSING COIL REPAIR REPLACE . Watch out: good practice following work on refrigerant piping systems or system evacuation and recharging within refrigerant includes the installation of a debris filter and refrigerant drier device. at REFRIGERANT DRIERS & FILTERS In case you didn't realize it, in order to solder a repair in an air conditioner or heat pump piping, tubing, evaporator coil/cooling coil, or condensing coil, it will first be necessary to remove all of the refrigerant from the system. The HVAC technician will connect a pump to pull a vacuum on the system to remove as much air, gas, debris, and moisture as possible.