A Sharp heat pump that no longer heats during the winter: fast and precise intervention by AirGreen
In the heart of Sainte-Julie , a loyal AirGreen customer contacted us about a heating problem with his Sharp Eco Inverter wall-mounted heat pump . Despite the reputation for reliability of this Plasmacluster Ion technology model, the system had not been producing sufficient heat for several days, even at full power.
With temperatures hovering around -10°C, the situation was becoming urgent. Our team quickly moved in to carry out a complete on-site diagnosis .
Initial inspection: a suspicious lack of pressure
Upon arrival, our certified technician noted several clues:
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The Sharp outdoor unit was working, but the compressor seemed to run continuously with no results .
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The fan was blowing out cold air instead of warm air.
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No error messages were displayed on the indoor module.
So we connected our service pressure gauges (visible in the photo) to measure the pressure in the refrigeration circuit. The verdict: partial lack of R410A refrigerant , probably caused by a micro-leak at a flare fitting.
Precise diagnosis: leak at the connection and drop in thermal efficiency
A careful visual inspection revealed traces of refrigerant oil on one of the connection nuts. This is often the typical sign of a slow leak , imperceptible in the short term but which, over the months, alters the performance of the heat pump and compromises heating in winter.
The consequences were clear:
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Pressure loss → drop in the evaporation point of the fluid → insufficient heat .
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Compressor overconsumption of electricity.
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Risk of premature wear of the inverter motor.
Step 1: Recover remaining gas and leak test
Before any recharge, our team recovered the residual refrigerant using an ecological recovery system that complies with the standards of the Quebec Ministry of the Environment .
Next, a nitrogen leak test was performed at 300 psi to pinpoint the leak. It was coming from the suction fitting , which was slightly loose.
After cleaning and drying, we replaced the flare ring , added a drop of POE refrigerant oil to lubricate the seal, and then tightened to the exact torque recommended by Sharp.
Step 2: Vacuum draw and calibrated recharge
Once the leak was repaired, we performed a deep vacuum down to 500 microns to remove any residual moisture in the circuit.
The heat pump was then accurately recharged to factory specifications for the Sharp Eco Inverter 12,000 BTU model.
Evaporation/condensation pressures and temperatures were carefully checked using a digital manifold.
Result: perfect nominal values , a sign that the circuit was once again watertight and stable.
Step 3: System Calibration and Defrost Check
We then activated the extended heating mode to monitor the heat pump's behavior in real conditions.
The discharge temperature sensor and the defrost sensor have been tested. An inverter module firmware update has been performed to improve automatic defrost management.
Finally, we checked the relative humidity level inside the home and noted better thermal homogeneity after 15 minutes of continuous operation.
Final result: winter comfort restored in Sainte-Julie
After intervention:
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The discharge temperature increased from 26°C to 42°C .
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The compressor has returned to a normal operating cycle .
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The noise level remained low thanks to the good balance of the fan.
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And above all, the customer found the comfort and warmth she expected without an increase in her electricity bill.
This well-maintained Sharp Eco Inverter heat pump is back in full operation—proof that inverter systems, when properly maintained, can deliver exceptional performance even in extreme cold.
AirGreen best practices: prevention and maintenance
This type of breakdown could have been avoided with annual preventive maintenance , including:
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Checking the tightness of the fittings .
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Cleaning the condenser and evaporator .
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Pressure and subcooling measurement.
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Inspection of the insulation of pipes exposed to frost.
At AirGreen, we strongly recommend that residents of Sainte-Julie, Brossard, Longueuil, Laval and Montreal schedule these maintenance sessions before winter to prevent performance losses and extend the life of HVAC equipment .
Local expertise, guaranteed results
Each AirGreen intervention is based on three pillars: precise diagnosis, sustainable intervention and total transparency .
Our technicians, specialized in Sharp, Fujitsu, Midea, Gree and Lennox brands, are experts in inverter systems and guarantee repairs that optimize both energy efficiency and comfort .
This repair in Sainte-Julie perfectly illustrates the rigor of our methods: from the leak test to the final recharge , everything is carried out according to the strictest standards of the HVAC sector in Quebec.