Repair of a Fujitsu wall-mounted heat pump in Laval-des-Rapides

A night service call for an R-410A refrigerant leak

At AirGreen , we often respond to urgent situations related to performance losses in Fujitsu wall-mounted heat pumps , especially in early spring, when systems switch from heating to cooling mode. This is exactly the case during this intervention in Laval-des-Rapides , where a customer contacted us in the evening: his unit was no longer producing heat and the outdoor compressor seemed to be running continuously without any tangible results.

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Diagnosis: a slow leak in the refrigeration circuit

Upon arrival, we immediately noticed that the Fujitsu wall-mounted heat pump , installed on a side wall of the residence, was displaying abnormally low pressure. Using our electronic manifold , we connected our high and low pressure hoses and found that the R-410A refrigerant had almost completely escaped from the circuit.

The signs observed:

• Warm indoor outlet air temperature despite heating mode being activated.

• Irregular compressor noise.

• Oil accumulation on a bend in the copper line, a typical sign of a microleak.

This slow loss, although minimal, was enough to drastically reduce the system's efficiency.

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Steps of repair

1. Leak detection and repair

We injected a fluorescent tracer into the circuit, then used a UV lamp to pinpoint the leak. It was coming from a cracked solder joint on the suction line at the compressor outlet. After purging and isolating the circuit, we made a silver solder repair , then performed a leak test under nitrogen pressure at 350 psi for 30 minutes. No pressure loss was observed.

2. Deep vacuum draw

Once the leak was repaired, we connected our dual-stage vacuum pump , providing a vacuum down to -500 microns . This step is essential to remove all traces of moisture and air from the system, thus preventing the formation of acid in the compressor.

3. Recharge with R-410A refrigerant

We then proceeded to a complete recharge of the system following the manufacturer's nominal charge, i.e. 1.25 kg of R-410A, measured on an electronic scale. The operation was carried out with the greatest precision:

• Low pressure: 115 psi

• High pressure: 385 psi

• Blowing temperature: 11°C in cold mode after stabilization

These values ​​confirmed a return to the original performance of the system.

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Final checks and recommendations

After recharging, the Fujitsu heat pump resumed stable and quiet operation. The customer immediately noticed the difference: cooler air, normal power consumption, and an automatic compressor shutoff when the target temperature was reached.

We recommended to the client:

• Have the refrigeration connections inspected every year , especially during seasonal transitions.

• Keep the exterior base clean and clear , as debris and moisture can accelerate corrosion of copper tubing.

• Plan for annual AirGreen preventive maintenance , which includes checking pressures, cleaning coils and measuring delta T.

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A typical intervention of AirGreen rigor in Laval

This repair perfectly illustrates our technical expertise and our commitment to the sustainability of HVAC systems . At AirGreen, we always prioritize the most reliable and cost-effective solution for our customers.

Our teams serve all of Laval , including Chomedey, Vimont, Sainte-Rose and Fabreville , as well as the North Shore and the South Shore for all your repair, maintenance or installation needs for Fujitsu, Gree, Midea, Sharp, Trane or Zephyr wall-mounted heat pumps .

By choosing AirGreen, each client benefits from field expertise, advanced diagnostic tools and local service across Greater Montreal.

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