AUTHOR
Mars, Founding Editor, Renewable Heating Hub
While truly noisy heat pumps are increasingly rare thanks to improved technology and design, a minority of installations can still create considerable problems; most often when systems are poorly installed or inappropriately located. This mismatch between expectations and reality can result in real distress for homeowners who suddenly find themselves living with distracting, often intrusive sounds.
On the Renewable Heating Hub forums, we continue to see sporadic posts from homeowners who are grappling with noise issues they never expected.
Take, for example, Lokisam, who shared their experience:
I’m shocked to find that I can hear my heat pump inside the house… I can hear it all the time in the living room (sometimes quieter, sometimes louder) and it’s been driving me nuts.
Their bedroom, located above the outdoor unit, suffers from whooshing and startup sounds that have already disturbed sleep. What’s more, the homeowner was told that the unit (an 8kW Samsung) was among the quietest on the market.
Another member, @sjn, reported a similar experience:
The compressor noise doesn’t vary like this when it’s on a domestic hot water cycle… but at other times it can sound more like someone using an electric pressure washer or an impact driver.
And it’s not just the external unit. Inside the home, pipework and components (especially if installed without sufficient vibration isolation) can act as amplifiers. Speaking from personal experience, I’ve found that even though our outdoor unit is about 20 metres from the house and completely silent inside, we still get a lot of hums and distracting sounds from our buffer tank and multiple circulation pumps. It’s those low-frequency noises that you begin to tune into, and again it comes down to installation.
Claire, another homeowner, shared a very relatable account:
We recently had a Daikin Altherma 11kW heat pump installed. We’re happy with how it’s heating our home and the costs, but I hate the thing due to the noise in our bedroom.
When we had our original survey for the heat pump, we were told we would not hear it indoors. I thought I’d hear it in the lounge, because it’s next to French doors. However, it isn’t a problem in the lounge as much, but the noise is so annoying in our bedroom. When it’s turned off, it’s such a relief, and I can’t sleep with it going. I’m not sure if it’s from the unit or the flow and return. It’s about 25-30 decibels inside the room.
While it is quieter than our old oil boiler, the oil boiler was in our utility room, so we didn’t hear it, and it was only noisy on start-up, whereas the heat pump runs a lot, especially in winter. And this is on the bedroom wall. So in the evening, I try to get our toddler to sleep, and it drives me mad.
While we do live in a quiet location, we also live next to a military air base, so we are used to noise, but this is just annoying, constant noise. Turn it off, and it’s like being out of a loud bar and being relieved to have peace.
Ally, a well-respected forum contributor and HVAC installer, suggests that these problems often stem from a substandard installation:
ASHP noise from the outdoor unit should not transmit through solid walls and double-glazed windows. If it’s clearly audible, reflective surfaces or poor pipework installation might be to blame. Flexible connections, rubber feet, insulated pipe clips… these are small details that make a big difference.
So why is this still happening?
Elton believes policy and regulation are lagging behind:
We urgently need a proper tonality measure. Coarse tonality can add +6dB(A), which is a significant jump. Remember, every 10dB is a doubling of perceived loudness. Without accounting for this, units can pass as permitted development (PD) even if they would fail environmental health tests for noise nuisance.
I don’t think we need to ban certain models outright, but we do need stricter guidance and enforcement, especially for more powerful units in dense residential settings. The lack of standardisation in how manufacturers report maximum noise levels only adds to the confusion.
There’s also a cultural issue, and Elton adds:
Noise is often dismissed as a ‘myth’ or something to laugh off.
That narrative might help push sales targets, but it doesn’t help the long-term sustainability of the rollout. When estate agents start advising people to avoid homes with heat pumps, we should all be paying attention.
The truth is, noise doesn’t need to be a problem. With proper planning, good product selection and thoughtful installation, most homeowners never even notice their systems running. But where corners are cut, the consequences can be life-changing, particularly when noise infiltrates bedrooms and living spaces.
Getting this right isn’t about demonising heat pumps; it’s about treating them seriously, as major pieces of infrastructure. If we want the transition to low-carbon heating to succeed, we need to build trust, and that means tackling and addressing noise head-on, not sweeping it under the rug.
Flexi-Orb Says:
There are some basic installation considerations that need a higher level of thought and investigation, along with discussions with the customer before committing to the siting of the Heat Pump. These may include not fixing the heat pump to a wall or near a bedroom window, and not hiding it at the side of the house with a fence in front of it – this won’t help with noise or its designed operation. It’s important to let the heat pump breathe, so positioning it at the back of the house gives it lots of room to dissipate the noise from the fans and the compressor.
– James Livingstone, Head of Certification
Properly installed heat pumps won’t cause a noise issue for you or your neighbours, and the Flexi-Orb Scheme includes a validated noise assessment methodology. Until now, the industry has relied on datasheet numbers, not real life situations.
– Chris Higgs, Wizard of Heat Pumpery
