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Réparation d’une thermopompe murale TCL à Sainte-Thérèse
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Repair of a TCL wall-mounted heat pump in Sainte-Thérèse

A TCL compressor that no longer started: a typical but critical breakdown

At AirGreen , we frequently work on TCL wall-mounted heat pumps , particularly in single-family homes on the North Shore . This time, our team was dispatched to Sainte-Thérèse for a TCL outdoor unit installed about five years ago that was no longer starting, despite a stable power supply. The customer reported that the indoor fan was working, but the blown air remained lukewarm, even in maximum cooling mode.

The objective: to quickly identify the cause of the compressor not starting and restore comfort before the rise in summer temperatures.

Diagnosis: Compressor inactive despite correct communication

Initial check

Upon our arrival, we carried out a series of tests:

  • voltage measured at the circuit breaker: 240V stable;

  • communication cable continuity: confirmed;

  • Main board intact, no error codes displayed.

Despite these results, the compressor remained silent at startup . By placing our current clamp, we noticed that no current was drawn during the cold call sequence. This indicated either a faulty starter (capacitor or inverter module) or a mechanically blocked compressor .

Step 1: Test the capacitor and inverter module

First we opened the side housing of the TCL compressor:

  • the starting capacitor showed slight deformation, a sign of thermal wear;

  • multimeter test: 0 μF — confirming that it was completely out of order .

The inverter module, for its part, displayed consistent voltages on the output phases, which ruled out an electronic fault.

The diagnosis was therefore clear: the capacitor had to be replaced .

Step 2: Replacement and recommissioning

After turning off the main power and disconnecting the original capacitor, we installed a new 40 μF / 450V capacitor , which is perfectly compatible with the TCL model.

We then have:

  1. tightened the electrical connections;

  2. secure the wiring with insulating ties;

  3. powered back on and restarted the system.

In less than 20 seconds, the compressor started and the outdoor fan began to rotate normally. An indoor discharge temperature of 7.8°C was measured after 10 minutes of continuous operation.

Step 3: Final checks and preventive maintenance

Before concluding, we have:

  • checked refrigerant pressures (R-410A): normal;

  • cleaned the external condenser with a blower;

  • applied a hydrophobic treatment to the fins to prevent corrosion;

  • validated electrical stability over three complete cycles.

We also advised the customer to opt for annual maintenance , which is essential to avoid overloading the compressor and premature deterioration of electronic components.

Results and customer feedback

The TCL system has returned to full performance:

  • operational compressor;

  • stable cooling cycle;

  • normal operating noise;

  • power consumption within tolerances.

The customer, satisfied to regain optimal comfort without costly replacement, highlighted our speed and clarity of explanations. We added his file to our AirGreen preventive monitoring program, guaranteeing an automatic reminder for the following year's maintenance.

The importance of electrical diagnosis on wall-mounted heat pumps

TCL heat pumps offer good energy performance, but like any HVAC unit, they require careful monitoring of their electrical components. Capacitors, in particular, undergo significant thermal cycling and age quickly if they are not checked every season.

Capacitor failure is one of the most common causes of compressor failures across all manufacturers (TCL, Midea, Zephyr, Gree, etc.). At AirGreen, our technicians carry these parts in inventory, often allowing for same-day repairs.

AirGreen: your HVAC partner on the North Shore

Thanks to our expertise and our complete stocks of parts for consumer brands like TCL, we ensure:

  • an accurate and transparent diagnosis ;

  • quick repair without unnecessary replacement;

  • complete coverage across Montreal, Laval, Longueuil, the North Shore and the South Shore .

We combine technology and know-how to ensure sustainable and energy-efficient comfort for every customer.

AirGreen — TCL heat pump repair experts in Montreal, Laval, Longueuil, North Shore and South Shore.
Fast, professional and certified service to keep your HVAC system operating at its full potential.