Why Is My Heat Pump Freezing Up in Summer? (And 5 Fixes That Could Save Your System)

Avoid the meltdown before it starts—how to stop your heat pump from icing over in the BC heat.

When your heat pump is freezing up in summer, something’s seriously wrong. It’s like seeing frost on your lawn in July—confusing, frustrating, and, if ignored, expensive.

At Eco Pro Heating, we get panicked calls every year from BC homeowners wondering, why is my heat pump freezing up in summer? You invested in efficient cooling. You expected comfort. And now, you’re staring at an icy outdoor unit while your home roasts inside.

Let’s fix that. Here’s what’s really happening, what it means, and what you can do right now to prevent a total breakdown.

Is your system already frozen? Skip to the Contact page and we’ll send a certified technician fast.

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What’s a Heat Pump Really Doing in Summer?

Before we tackle the freezing, it’s worth understanding what your heat pump is designed to do.

Unlike a furnace, which creates heat, or a traditional AC, which just cools, a heat pump transfers heat both ways. In summer, it pulls warm air from inside your home and releases it outdoors through refrigerant-filled coils. It does this using a system of:

• Indoor air handlers
  
• Outdoor compressor
  
• Refrigerant lines
  
• Evaporator coils

It’s a smart, efficient system. But when one part goes out of balance—airflow, pressure, dirt, or refrigerant—it can throw everything off. And that’s when you start asking: why is my heat pump freezing up in summer?

Learn more about our team and our values at Eco Pro Heating.

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1. Low Refrigerant: The #1 Culprit

Why is my heat pump freezing up in summer? Most of the time, it’s low refrigerant.

When your refrigerant levels are low, it causes pressure inside the system to drop. That makes your evaporator coil much colder than it should be. Add moisture in the air—and boom: ice.

Low refrigerant usually points to a leak, and leaks require certified handling. DIY won't cut it here.

What to do:

• Shut off your unit.
  
• Switch your thermostat fan to “on” (not “auto”) to thaw the ice.
  
• Call a certified HVAC technician to check for leaks, recharge, and test the system.
  
  

Book your inspection today before the problem gets worse.

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2. Dirty Coils Are Insulating the Problem

Your heat pump works by exchanging heat across metal coils. But when those coils are coated in dust, grime, or pollen, they act like insulation—trapping cold in.

This leads to inefficient heat transfer and often a full freeze-up during cooling season.

What to do:

• Clean coils carefully with a garden hose (no pressure washer).
  
• Never use chemical cleaners unless instructed by a professional.
  
• Schedule a seasonal maintenance service.
  
  

Check out available heat pump rebates in BC if you're thinking of upgrading your unit.

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3. Poor Airflow Is Starving Your Coils

Your system needs a steady flow of warm indoor air over the coils to function properly. But clogged filters, blocked vents, or a sluggish blower motor can all restrict airflow—and that’s a recipe for ice.

Symptoms of poor airflow:

• Weak air pressure from vents
  
• Uneven cooling in rooms
  
• Rising humidity indoors
  

What to do:

• Replace filters every 30–90 days
  
• Keep return vents unblocked
  
• Have your blower motor tested if airflow seems low
  

Explore our full HVAC services on the homepage.

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4. Thermostat Settings That Confuse Your System

Sometimes, why is my heat pump freezing up in summer? has a simpler answer: thermostat miscommunication.

Setting your fan to “auto” during a freeze-up keeps cold air from moving, allowing ice to accumulate. Similarly, setting the temperature too low for long periods may overwork your system.

What to do:

• Set your thermostat fan to “on” during a freeze
  
• Avoid setting temps lower than 20°C for extended periods
  
• Invest in a smart thermostat to regulate runtime and reduce wear
  

Have questions about smart thermostats? Reach out today.

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5. The Problem Could Be Installation or Age

If your system is constantly freezing—even after filter changes and cleanings—it may be due to poor installation or simply age.

Heat pumps that are:

• Improperly sized
  
• Installed without airflow consideration
  
• 10+ years old
  

…are more prone to freeze-ups, especially during extreme BC summer conditions.

What to do:

• Schedule a system evaluation
  
• Ask about sizing and load requirements for your home
  
• Consider upgrading to a newer, rebate-eligible unit
  

See if your home qualifies for heat pump rebates

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Why Is My Heat Pump Freezing Up in Summer? Quick Troubleshooting Guide

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Let Eco Pro Heating help with a free inspection

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How to Prevent Your Heat Pump from Freezing Up in BC

Prevention is always cheaper than repair. Here's what we recommend for BC homeowners:

• Seasonal Maintenance: Spring and fall tune-ups catch problems early.
  
• Filter Discipline: Mark your calendar—new filter every 1–3 months.
  
• Clean Surroundings: Keep outdoor units clear of leaves, grass, and clutter.
  
• Watch Your Thermostat: Don’t overcool or overwork the system.
  

BC’s climate is moderate—but heat waves are getting hotter and more frequent. A frozen unit in the summer isn’t just inconvenient, it’s dangerous for homes with infants, pets, or seniors.

See our full story and why customers trust Eco Pro

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Q&A: Why Is My Heat Pump Freezing Up in Summer?

Q: Can I run my heat pump while it’s frozen?
A: No. Running a frozen unit puts stress on the compressor and can cause permanent damage. Turn it off immediately.

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Q: How long does it take to defrost?
A: With the fan set to “on,” most minor freezes can melt in 1–2 hours. If ice persists, call for service.

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Q: Is this covered under a warranty?
A: It depends. Mechanical failures are often covered. Maintenance issues (like dirty filters) usually are not. We can help check.

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Q: Should I upgrade my heat pump?
A: If it's over 10 years old or needs frequent repairs, it may be time—especially with BC’s generous rebates.

Ask us about your system’s lifespan and rebate eligibility

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The Bottom Line

If you’re asking why is my heat pump freezing up in summer, don’t wait until it shuts down completely. It’s almost always preventable, and almost always fixable—if you act fast.

Eco Pro Heating is your trusted partner for heat pump repair, installation, and seasonal care in BC. With rebate knowledge, expert techs, and top-tier customer service, we’ll get you cooling again fast.

Book your service now or see rebate options to upgrade your system.