Refrigerant leak problem detected in time thanks to in-depth diagnosis
At AirGreen , our expertise in residential HVAC system repair often leads us to work on Fujitsu wall-mounted heat pumps that are experiencing performance losses or refrigerant circuit failures. This project, carried out in Boucherville , perfectly illustrates the importance of a thorough diagnosis when an indoor unit shows signs of failure.
Context of the service call
The customer contacted us after noticing that their Fujitsu system was no longer producing heat despite the fan appearing to be running. The indoor unit was blowing warm or even cold air, even after several minutes of use.
Upon our arrival, our AirGreen-certified technician performed a thorough visual inspection of the wall unit, installed in a living room with a concrete ceiling—a setting typical of modern buildings on the South Shore.
Initial diagnosis: suspicion of internal leak
Upon removing the front cover, we discovered traces of refrigerant oil near the copper coil and suction pipe connection . This sign is often indicative of a micro-leak in the refrigerant circuit .
Using an electronic detector, the presence of R410A refrigerant was confirmed in this area, confirming the leak.
Symptoms observed:
-
Rapid drop in pressure on the low line.
-
Oil accumulation visible at the bend of the coils.
-
Insufficient blowing temperature in heating mode.
Repair Steps
-
Disassembly and release of the inner coil
The wall unit was carefully disassembled, revealing the internal copper and aluminum coil. A slightly oxidized area at the factory solder joints caught our attention. -
Precise location of the leak
By injecting a tracer gas (nitrogen + hydrogen), we confirmed a slow leak at a bend connection on the upper part of the coil. -
Copper-phosphorus brazing repair
After draining the circuit and purging the line, our technician reapplied the silver solder at the leak point, ensuring a lasting seal. This operation requires precise temperature control to avoid damaging the coil structure. -
Leak test and repressurization
The system was pressurized to 350 psi of nitrogen for 45 minutes. No pressure drop was observed, confirming the successful repair. -
Vacuum extraction and recharging with R410A refrigerant
A vacuum was applied for 30 minutes, followed by recharging to the exact factory charge indicated on the Fujitsu nameplate. -
Complete reassembly and performance test
After replacing the housing and sensors, we ran a full heating and cooling cycle to check performance.
Results and final performance
At the end of the intervention:
-
The blowing temperature reached 44°C in heating mode .
-
Refrigeration pressures have stabilized at values in line with Fujitsu specifications.
-
The compressor was operating at full efficiency without overloading .
The customer immediately felt the difference: restored thermal comfort and quiet operation .
Prevention and advice
We took the time to explain to the customer that micro-leaks on the coils can occur after several years of operation, especially in environments where temperature and humidity variations are frequent.
Our recommendations:
-
Have the refrigerant level checked every two years .
-
Avoid cleaning the coils yourself with unsuitable products.
-
Schedule annual AirGreen preventive maintenance including cleaning, pressure testing and calibration of probes.
AirGreen Expertise: Precision and Sustainability
This Fujitsu wall-mounted heat pump repair in Boucherville demonstrates our commitment to quality, durability, and energy performance . Through our accurate diagnosis and professional brazing techniques, we extended the system's life and restored optimal performance—without costly replacement.
Whether in Montreal, Laval, Longueuil, on the North Shore or the South Shore , our teams respond quickly with constant attention to detail and certified technical mastery.