Heat Pump Not Cooling? Here’s What Might Be Wrong (And How to Fix It)

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When your heat pump stops cooling during a sweltering BC summer, it’s not just inconvenient—it can make your home downright unbearable. But before you panic and assume the system is broken beyond repair, take a breath. A non-cooling heat pump can be caused by several surprisingly common issues, many of which are fixable without replacing your unit.

In this guide, Whyte Mechanical walks you through the most likely reasons your heat pump is not cooling, how to identify them, and when it’s time to call in a certified pro.

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Is Your Thermostat Set Correctly?

It sounds obvious, but we’ve seen it all. A thermostat that’s set to the wrong mode or temperature can mimic a serious system failure. Make sure your thermostat is:

• Set to cooling mode (not heat or auto)
• Programmed to a temperature lower than your current room temp
• Functioning properly (some smart thermostats show error codes or lost Wi-Fi connections)

Also, check the batteries if your thermostat uses them. If it’s not communicating with your system properly, the problem starts there.

Not sure if your thermostat is the issue? Use our free HVAC diagnostic tool.

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Could It Be a Tripped Breaker or Power Issue?

Your heat pump relies on a steady stream of electricity to run. If your circuit breaker trips, it might shut off power to the outdoor or indoor unit—or both. Here’s what to do:

• Check your main panel and flip any tripped breakers back to ON
• Look for a separate outdoor disconnect switch (often near the unit)
• Watch out for frequent tripping—that usually signals a deeper issue like a bad capacitor or motor

Still losing power to your heat pump? Our licensed BC technicians can take a look.

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Is the Air Filter Dirty or Clogged?

A clogged air filter restricts airflow to the indoor coil, preventing the system from cooling properly. If your vents are blowing warm or weak air, it could be a dirty filter.

• Replace filters every 30–90 days, or more often if you have pets
• Look for signs of dust buildup near vents or on the blower unit
• Bonus tip: A clogged filter can also lead to ice buildup on your indoor coil

Need filter replacement as part of routine maintenance? Get an HVAC checkup quote today.

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Is the Outdoor Unit Blocked or Dirty?

Your heat pump’s outdoor unit needs breathing room to release heat. Dirt, debris, cottonwood fluff, or overgrown shrubs can block airflow and reduce cooling efficiency.

• Inspect the outdoor coil for dirt, leaves, or visible buildup
• Hose down the unit (gently) to clean the fins
• Leave at least 2 feet of clearance around the unit

Noticed the outdoor unit is unusually hot or loud? Our techs can inspect it safely.

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Is the Reversing Valve Stuck or Broken?

The reversing valve is what allows your heat pump to switch between heating and cooling. If it gets stuck, your system may be blowing hot air in the summer—even if everything else is fine.

• This issue often looks like a working system blowing the wrong air temperature
• Only a trained HVAC pro should diagnose or replace a reversing valve

Worried your reversing valve is stuck in heating mode? Book a professional inspection with Whyte.

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Could Low Refrigerant Be the Cause?

Refrigerant is the lifeblood of your cooling system. If there’s a leak or the system wasn’t charged correctly during installation, your heat pump can’t cool effectively.

• Signs include ice on refrigerant lines, low airflow, or a hissing sound
• Refrigerant leaks must be fixed and recharged by certified technicians (R-410A or similar refrigerants are regulated)

Need to check for a refrigerant leak? We’ll diagnose and recharge safely.

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Is Your Heat Pump Constantly Running But Not Cooling?

If your unit runs nonstop without cooling your space, the issue could be:

• Incorrect thermostat settings
• Low refrigerant levels
• A failing compressor contactor (which controls cooling cycles)
• Oversized or undersized unit for your home

Curious if your system is properly sized? Try our instant quote calculator to find out.

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Should You Try DIY Fixes or Call a Professional?

Here’s a simple way to decide:

✅ DIY:

• Reset the thermostat
• Replace air filters
• Clean outdoor unit
• Flip breakers back on

🚫 Call Whyte if:

• Air is warm after DIY checks
• Ice forms on coils or lines
• Breakers trip repeatedly
• You hear hissing, buzzing, or clicking sounds

Our local team in the Lower Mainland understands the specific challenges of BC homes—from salty air near the coast to humid summers in the valley. We’ll fix your system fast, cleanly, and transparently.

Need fast help? Contact Whyte Mechanical today and restore your home’s comfort.

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FAQs About Heat Pumps That Aren’t Cooling

Q: Why is my heat pump running but not blowing cold air?
A: This usually means your reversing valve is stuck, refrigerant is low, or airflow is blocked.

Q: Can a dirty filter cause my heat pump to stop cooling?
A: Yes. Dirty filters restrict airflow and can freeze coils, stopping your system from cooling.

Q: What should I do first if my heat pump isn’t cooling?
A: Check your thermostat settings, then the filter, then the circuit breaker. Still stuck? Call a pro.