Why Is My Air Source Heat Pump So Noisy? (UK Fix Guide 2025)

Quick Summary (TL;DR)

• Some noise is normal: A low hum or a gentle whoosh of air is standard for an operating heat pump.

• Abnormal noises like loud buzzing, grinding, or rattling often point to a simple, fixable issue like loose panels, debris, or an unlevel unit.

• DIY Fixes First: You can often solve the problem quickly by tightening case panels, clearing leaves/debris, and ensuring the unit is level on its base.

• Call a Pro When: If you hear screeching or grinding, the noise persists after basic checks, or the system isn't heating properly. Don't touch electrical components yourself.

Why Is My Air Source Heat Pump So Noisy? (UK Fix Guide 2025)

Hear a new buzz, rattle, or hum from your heat pump? While air source heat pumps (ASHPs) aren't silent, a sudden or excessively loud noise can be alarming. Before you worry about a costly repair, know this: many common noise issues have simple, DIY fixes.

This guide will help you play detective. We’ll break down what different sounds mean, the quick checks you can do yourself to fix a noisy heat pump, and crucially, when it's time to call in the professionals at Air Source Company for help in the Midlands.

First, Know What’s "Normal" for a Heat Pump

A completely silent heat pump doesn't exist. Modern models are designed to be very quiet, typically operating between 40-60 decibels (roughly the level of a quiet conversation or a refrigerator). You should expect to hear:

• A consistent, low-frequency hum from the compressor.

• The sound of air moving from the fan, which may vary in intensity.

• A periodic "whooshing" or mechanical sound during its defrost cycle.

Decoding the Noise: A Troubleshooting Guide

Use this table to quickly identify potential causes and solutions.

Noise Type	Likely Cause	DIY Fix	Call a Pro?
Buzzing / Vibrating	Loose side panels or mounting bolts.	Tighten all visible screws and panels on the outdoor unit.	If buzzing continues from inside the unit.
Rattling / Clanking	Leaves, twigs, or debris hitting the fan.	Turn off power. Carefully remove debris from around the fan and coil.	If you can't safely clear it or the fan blade is damaged.
Grinding / Screeching	Worn-out fan motor bearings.	None.	Yes, immediately. This requires professional part replacement.
Gurgling / Bubbling	Air in the refrigerant circuit.	None.	Yes. The system may need to be purged of air by a certified engineer.
Loud Humming	Unit is unlevel, causing vibration.	Check the unit is level on its base. Pack shims under the feet if needed.	If you cannot safely level it yourself.
Constant Loud Fan	Dirty coils forcing the fan to work harder.	Turn off power. Gently clean the aluminium fins with a soft brush.	For a deep clean or if fins are bent.

Customer Story: Solving a Mysterious Midlands Rattle

"We had a really annoying rattling sound that started every time the wind picked up. We thought the worst – a broken compressor. An engineer from Air Source Company came out and found a single, loose side panel that was vibrating against the frame. He tightened it in 30 seconds and the noise was completely gone! It saved us a huge diagnostic bill and showed us how simple the fix can be."— David & Sophie, Leicester

When to Call a Professional: Safety First

While DIY fixes can solve many issues, some problems require expert hands. Call a certified engineer if you experience:

• Any electrical buzzing from within the unit (not just the panel).

• Grinding or screeching noises that indicate mechanical failure.

• The system is noisy AND not heating properly.

• You are not comfortable performing basic checks safely.

Remember: Tampering with internal electrical or refrigerant components is dangerous and will void your warranty.

About Air Source Company

Air Source Company is your local Midlands expert for heat pump installation, servicing, and repair. Our MCS-certified engineers cover Nottingham, Leicester, Derby, and the surrounding areas. We understand the unique installation challenges and weather conditions of our region, ensuring your heat pump isn't just quiet, but also perfectly optimized for your home. We believe in honest, transparent advice—whether it's a simple fix or a complex repair.

Don't let a strange noise turn into a major repair bill. A quiet heat pump is an efficient heat pump.

👉 Get Peace of Mind with a Professional Health Check!

For homeowners in the Midlands, Air Source Company offers a comprehensive Noise Diagnostic Service. Our engineers will identify the source of the noise, perform any necessary fixes, and ensure your system is running safely and efficiently.

Book your service visit online today for fast, local expertise.

Frequently Asked Question(FAQ's)

Is it normal for a heat pump to be noisy?

It is normal for an air source heat pump to produce a low humming sound and the noise of moving air from its fan. However, loud, disruptive noises like buzzing, grinding, or persistent rattling are not normal and usually indicate a problem that needs addressing.

How can I make my air source heat pump quieter?

You can make your heat pump quieter by ensuring all external panels are tightly screwed on, keeping the area around the unit clear of leaves and debris, and checking that the unit is level on its mounting base to prevent excess vibration. Planting a small screen or shrubbery (with adequate clearance) can also help buffer sound.

Why is my heat pump making a loud buzzing noise?

A loud buzzing noise from your heat pump is most commonly caused by a loose or vibrating side panel on the outdoor unit. The first step is to safely check and tighten any visible screws. If the buzz persists internally, it may be an electrical issue, and you should call a professional.

What does a failing heat pump sound like?

A failing heat pump often makes unusual noises like loud grinding or screeching, which typically point to a failing fan motor or compressor. These sounds, especially if accompanied by a loss of heating performance, require immediate professional attention.

Can I fix a noisy heat pump myself?

You can fix some causes of a noisy heat pump yourself, such as tightening loose panels, clearing debris from the fan, or levelling the unit. However, you should never attempt to fix internal electrical components or refrigerant issues. For any persistent or concerning noises, always call a certified engineer.