Why Is My Heat Pump So Loud in Winter? Tips for a Quieter System

Introduction

You’re enjoying your cozy, energy-efficient home… then suddenly, your heat pump starts humming, buzzing, or clanking—especially in the winter. Is something broken?

Not necessarily.

While cold-climate heat pumps are quieter than ever, winter operation can still introduce some unexpected sounds, especially during defrost cycles or on older models. In this post, we’ll explain why your heat pump might be louder in winter, what’s considered “normal,” and how to quiet things down without sacrificing performance.

Why Do Heat Pumps Get Louder in Winter?

There are a few natural reasons your heat pump might sound different—or louder—during cold months.

Common Causes

• Defrost cycles: When the system reverses to melt frost, you may hear a “whoosh,” gurgling, or hissing sound.
• Fan blades hitting snow or ice: A partially blocked fan can vibrate or thump.
• Compressor strain: The system works harder at -15°C and below, especially if undersized.
• Metal contraction: Exterior components may creak as they expand and contract in freezing temps.

Example: A homeowner in Ottawa reports their unit makes a short, deep buzz during defrost but runs quietly the rest of the day—a normal sound for that brand.

What’s Considered “Normal” Heat Pump Noise?

Let’s break it down:

Heat Pump Noise Table

Sound	Possible Cause	Is It Normal?
Low hum	Compressor running	Yes
Gentle whoosh	Defrost mode	Yes
Gurgling	Refrigerant flowing	Yes
Light tapping	Expansion/contraction	Yes
Loud clanking or rattling	Loose part or debris	No
Fan scraping sound	Ice or snow in blades	No
High-pitched whining	Failing motor	No

Newer heat pumps often run between 40–55 dB (similar to a quiet dishwasher). Older or improperly installed units may exceed 65+ dB.

How to Quiet a Noisy Heat Pump in Winter

Here are tips to minimize sound without compromising function:

Noise-Reduction Tips

• Clear snow and ice from the unit regularly.
• Leave 18–24 inches of clearance on all sides.
• Mount your unit on a vibration-isolated stand.
• Use a rubber sound pad under the base.
• Add a snow shield or roof drip guard.
• Keep screws and brackets tight (metal loosens over time).
• Install the unit away from bedroom windows.

Homeowner tip: “We added rubber bushings between the bracket and wall. It cut the vibration noise in half!”

Choosing a Quieter Heat Pump Model (For New Installs)

If noise is a top concern, ask your installer about these quiet features:

Quiet Features to Look For

• Variable-speed inverter compressors → Smooth, low-noise operation.
• Low-decibel fan blades → Aerodynamic designs reduce turbulence.
• Cold-climate models → Designed to reduce compressor strain in winter.
• Sound rating labels → Measured in decibels (dB); aim for ≤55 dB.

Quiet Canadian-Favourite Brands

• Mitsubishi Zuba Central.
• Daikin Aurora.
• Bosch Climate 5000.
• LG Red Series.
• Fujitsu Halcyon XLTH.

Look for systems with night/silent mode—they can reduce fan noise during sleep hours.

When to Call a Professional

If you hear anything alarming or your system suddenly gets louder, it’s time for a checkup.

Call a Pro If:

• The noise is new or getting worse.
• You hear grinding, scraping, or clicking.
• Your indoor air feels cooler during heating mode.
• You see vibration marks on walls or siding.
• Your neighbours can hear it clearly through the wall.

Pro Tip: Book an annual winter prep check before cold weather hits. A tech can lubricate parts, secure mounts, and clear obstructions.

Conclusion

Some heat pump noise in winter is totally normal—especially during defrost mode or in deep cold. But with the right model, maintenance, and positioning, your heat pump can hum quietly along while keeping your home warm and efficient all season long.