Common Pitfalls to Avoid When Installing or Replacing a Ductless Wall-Mounted Heat Pump in Quebec
Through our many wall-mounted heat pump installation projects across Montreal, Laval, Longueuil, the North Shore and South Shore, we’ve seen time and time again that many homeowners face the same issues or uncertainties when choosing, installing, or replacing their system. These mistakes, although frequent, can lead to unnecessary costs, reduced performance, or even premature wear of the unit.
At AirGreen, we believe it's essential to share our expertise to help Quebecers make informed, long-lasting decisions when it comes to HVAC. Here’s a breakdown of the most common mistakes we encounter in the field, along with our concrete recommendations to avoid them.
Not Considering the Right Size and BTU Capacity
One of the most common pitfalls is choosing a wall-mounted heat pump with a BTU rating that doesn't match the size or layout of the space. An oversized unit will waste energy and cycle on and off too frequently, while an undersized unit will run non-stop, which shortens its lifespan and fails to provide consistent comfort.
Our recommendations:
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Always request a professional heat load assessment before buying.
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Avoid estimates based solely on square footage. Factors like insulation, window orientation, and ceiling height affect thermal load.
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For example, a 12,000 BTU wall-mounted heat pump might suit a 500 sq. ft. living room, but if there are large south-facing windows, a 15,000 BTU unit might be more appropriate.
Ignoring Existing Electrical Conditions
Far too often, homeowners purchase a heat pump without verifying whether their electrical setup is compatible with the chosen unit (115V or 220V). This results in either unexpected electrical work or delays due to panel upgrades.
Real-world example:
In a project in Boucherville, we recommended an 18,000 BTU Sharp ZU1 unit, as it’s one of the only models compatible with 1/4 - 3/8 piping and the existing electrical wiring. The customer avoided expensive electrical modifications and any damage to their newly renovated wall.
Choosing a Model That’s Incompatible With Existing Lines
Some heat pump models are not compatible with the previously installed refrigerant lines or setup dimensions. This often leads to the need for a full system replacement, which can be costly.
Case in point:
In Laval, a customer simply wanted to replace their old unit. Thanks to our Sharp heat pump offering, which is one of the only models to use 1/4 - 3/8 piping even for 18,000 and 24,000 BTU models, we were able to reuse the existing lines, avoiding a full system overhaul.
Neglecting Regular Maintenance
One of the most overlooked aspects is HVAC maintenance. A neglected wall-mounted heat pump accumulates dirt, loses efficiency, consumes more electricity, and wears out faster.
What we recommend:
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One professional maintenance visit per year, including indoor unit cleaning, coil washing, refrigerant pressure check, and condensate drainage inspection.
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On top of that, clean the filters monthly during peak usage seasons.
Overlooking Grant Eligibility
With Hydro-Québec’s LogisVert grants, several heat pump models qualify for rebates of up to $2,172. Yet many homeowners miss out either due to lack of information or because they chose a model that wasn’t eligible.
AirGreen Tip:
We always include this analysis in our proposals. During a recent installation in Sainte-Julie, the customer received a $1,704 rebate by choosing a Gree Extreme 18,000 BTU model, which qualifies under the LogisVert program.
Focusing Only on the Lowest Price
Opting for the cheapest heat pump on the market might seem financially sound at first glance, but it often leads to mediocre performance, shorter durability, and poor after-sales service.
Our approach:
At AirGreen, we offer a carefully selected lineup of trusted brands: Fujitsu, Gree, Sharp, Midea, Bosch, Lennox. Each brand is chosen for its performance in Quebec’s climate, energy efficiency, and solid warranty coverage.
What You Should Always Check Before Installing a Wall-Mounted Heat Pump
Always verify:
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The BTU output in relation to your actual needs
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The compatibility of the refrigerant lines and existing installation
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The voltage and capacity of your electrical panel
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The required maintenance frequency
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Whether your heat pump qualifies for a government rebate
Why Trust AirGreen?
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We’ve installed hundreds of wall-mounted heat pumps across Montreal, Laval, Longueuil, the South Shore and North Shore
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Our certified technicians receive continuous training on the latest HVAC technologies
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We perform a complete technical assessment, offer responsive after-sales service, and provide custom offers for each situation, including yearly maintenance
Conclusion: Make Informed Decisions, Enjoy Long-Term Comfort
Avoiding the mistakes above will help you maximize the performance of your wall-mounted heat pump, reduce your energy bills, and ensure optimal year-round comfort. With AirGreen, you’re supported every step of the way—from choosing the right model to flawless installation, regular maintenance, and guidance on available rebates.