Rapid intervention in the middle of winter: a heat pump that refuses to heat
At AirGreen , we know that a wall-mounted heat pump that stops providing heat in the middle of February can quickly turn a cold day into a real emergency. This is exactly the situation encountered during this service call in Sainte-Thérèse , on the North Shore, where a Haxxair outdoor unit was showing signs of weakness during periods of extreme cold.
Context of the intervention
The customer, a single-family home owner, noticed two days ago that his heat pump was no longer producing warm air. The unit was operating intermittently, and frost was abnormally accumulating on the outdoor coil . Despite several restarts, the system consistently switched to safety mode.
Upon our arrival, AirGreen technicians undertook a complete diagnosis of the HVAC system to identify the source of the problem.
Initial diagnosis: several possible causes
Our on-site observations revealed:
-
A lower than normal refrigerant level , detected using the pressure gauge connected to the unit.
-
A heat exchange coil clogged with ice , restricting airflow.
-
An overworked compressor , showing short cycles.
-
A defrost probe whose resistance values were out of tolerance.
These clues indicated a slow refrigerant leak combined with a faulty defrost sensor , a typical scenario when the unit has been operating in extreme temperatures without preventive maintenance for several seasons.
Steps of repair
-
Complete defrosting of the unit
-
Application of a professional non-corrosive de-icer to free the fins.
-
Check ventilation and clear frozen condensation drain.
-
-
Inspection of the refrigeration circuit
-
Using an electronic detector to locate a microleak at a flare fitting.
-
Cleaning the area and completely tightening after replacing the gasket.
-
-
System repair and recharge
-
Vacuum for 25 minutes to dry the circuit.
-
Recharge with R-410A refrigerant according to the set pressure from the manufacturer Haxxair.
-
Checking the pressure balance and correct operation of the compressor.
-
-
Replacing the defrost sensor
-
Installation of an original Haxxair temperature sensor.
-
Calibration test to ensure accurate triggering of the defrost cycle.
-
Results after intervention
Upon restarting, the blowing temperature increased from 16°C to 31°C , confirming the return to optimal performance. The outdoor unit was now performing regular and efficient defrost cycles. The customer was able to observe a rapid rise in the indoor temperature , with stable operating noise and controlled energy consumption.
AirGreen tips to avoid this type of breakdown
To extend the life of a wall-mounted heat pump, our technicians recommend:
-
Annual preventative maintenance , including cleaning the coils and checking the pressures.
-
Clearing snow around the outdoor unit to prevent ice formation.
-
An inspection before winter to ensure the good condition of the probes and connections.
-
Using an automatic defrost mode configured according to the actual outside temperature.
Expertise and reliability signed AirGreen
This intervention in Sainte-Thérèse perfectly illustrates our approach: diagnose accurately, repair efficiently and prevent future problems . At AirGreen, each service call is treated with the same rigor, whether it is a Haxxair heat pump , a Fujitsu , a Midea or a Sharp .
Our team serves Montreal, Laval, Longueuil, the North Shore and the South Shore daily, offering complete HVAC repair and maintenance services for all types of wall and central systems.