Pros and cons of air source heat pumps: are they worth it?

02 October 2023 | OVO Energy

Here at OVO, we think heat pumps are the future of home heating. They’re green, efficient, and the technology behind them is clever. We’ve put together this guide which explains the pros and cons of air source heat pumps.

Interested in saying goodbye to gas? Get your heat pump through OVO.

You can now get your heat pump installed through our exclusive partnership with Heat Geek. With a heat pump, you can save up to £210 a year on your heating bills compared to a gas boiler.1 You’ll also unlock our free add-on, Heat Pump Plus, which gives you a cheaper electricity rate to power your heat pump for less.

Find out more and register your interest here for updates on our add-on and when we’re installing in your area.

What are the pros of air source heat pumps?

1. They have longer lifespans than traditional boilers 

We’ll start with one of the biggest pros of air source heat pumps: they’re a long-term investment for your home. If they’re well maintained, these heat pumps can last for as long as 20 years.  Compare that to traditional gas boilers, which need updating much faster. Usually, a gas boiler needs replacing every 15 years at least. This means that air source heat pumps can last 25% longer!

What’s more, even in colder weather heat pumps are more efficient than gas boilers – around four times as efficient.

2. They work no matter what the temperature is outside

A myth about air source heat pumps is that they’re not very useful when the weather is cold. It’s true that the efficiency of an air source heat pump might drop slightly in winter, but you won’t feel the chill. Your heat pump will still keep your house warm when temperatures outside are as low as -15C provided the rest of the heating system is designed to do so.

In fact, some air source heat pumps can even do the opposite, and cool your house down during the hot summer months. It’s like having a boiler and an air-conditioning unit all in one!

An OVO engineer shows an older couple how to use the heat pump on their phone. They are stood outside.

3. They don’t give off any nasty carbon emissions

This is, of course, the biggest advantage of heat pumps: they’re a greener way of heating your home. 

Natural gas and crude oil – which are burned to power gas and oil boilers – are both types of fossil fuels. Not only are fossil fuels a limited resource, but when they’re burned, they release greenhouse gases into the atmosphere, including carbon dioxide. 

Air source heat pumps don’t directly release any carbon emissions into the atmosphere. They run entirely on electricity. This means that when run on renewable electricity, they’re as green as can be.

4. They’re safer than gas or oil-fired boilers 

Because air source heat pumps run on electricity, there’s no flammable fuel inside them, like gas or oil. This means that they’re generally safer. 

Also, there’s no risk of having a carbon monoxide leak when your home has a heat pump. Carbon monoxide poisoning can be fatal and is an underdiagnosed problem.

5. Most people won't need to get planning permission to install one

There are certain cases in which you might need to get planning permission. For example, if your home is in a conservation area. However most homes won't need to go through the long process of applying for planning permission as air source heat pumps have been a “permitted development” since 2011.

But you do need to follow a few rules, especially if you’re applying for funding through the Boiler Upgrade Scheme, like making sure your installer is certified by the Microgeneration Certification Scheme. You’ll also need to make sure your heat pump is a metre away from the boundary of your property and doesn’t go over a noise limit. Planning Portal has an extensive list of the necessary requirements.

6. It’s less disruptive than installing a ground source heat pump

Installing ground source heat pumps can be a long process, digging up holes in the ground to lay down pipework. Air source heat pumps can usually be installed much faster, in around five days. Less outdoor space required too. And less outdoor space is required too.

7. You can get some financial support for installing one

The Boiler Upgrade Scheme is an initiative which gives homeowners a one-off grant of £7,500 when they install an air source heat pump.  This has recently been updated from £5,000. 

Find out if you're eligible for the Boiler Upgrade Scheme.

An older couple in their home with heat pump in background. The woman sits on the chair while the man stands.

What are the cons of an air source heat pump?

Here are some of the main cons of air source heat pumps, which are worth thinking about before committing to one.

1. They can be more expensive to install than a boiler

Heat pump prices are falling, and will continue to drop as the market for them gets bigger. But – unless you’re getting a new cylinder anyway – they can still be a costly investment, even with the £7,500 Boiler Upgrade Scheme.

One of the biggest factors keeping the price of heat pump installation high is the lack of engineers who can do it. As heat pumps become more popular, there’ll be more qualified engineers.Our friends at Heat Geek have a nationwide network of award-winning installers – which is one of the reasons we’re partnering with them to test out our new heat pump offering. Register your interest and we’ll let you know when we're installing in your area.

2. They can make noise – but not as much as you might think

One disadvantage of air source heat pumps that’s often talked about is that they’re noisy. This is actually a bit of a myth.

It’s true that older, bulkier heat pumps can be noisy but modern heat pumps shouldn't sound any louder than your freezer. And as they're installed outside, it won’t usually be a sound you can hear indoors. Usually, air source heat pumps make a noise of about 40 to 60 decibels, which is no louder than a combi boiler. They tend to be quieter in the summer – when you might be outside more – and noisier on cold winter nights, when you’re more likely to be inside with the windows closed.

3. You might also need to get larger radiators

The larger the radiators that your heat pump is connected to, the more efficient your system will be. This is because heat pumps work at low temperatures and take a little longer than gas central heating to get up to temperature. It’s common for at least a couple of radiators to be replaced to make sure your system is efficient and will keep you warm on the coldest winter night

Are heat pumps any good in winter?

Yes! Heat pumps can still heat your home even in temperatures as low as -15C.

It’s a bit harder for your heat pump to work when it’s cold outside. But, there are a few things you can do to make sure it’s working as efficiently as possible, such as:

  • Insulating your home properly 
  • Use an installer that can design the heating system to work well with the heat pump in winter
  • Making sure the pump itself is clear of any debris

So: is it worth getting an air source heat pump?

There are many factors when thinking about getting a heat pump, including the size of your home, whether or not you’re connected to the gas grid, your finances and more. If you choose an engineer that designs and installs correctly, you will be sure to end up with a brilliantly performing heat pump. 

We think heat pumps are an excellent choice. Why? Because they’re helping us fight the climate crisis, one home at a time. 

To get to net zero, we all need to think about what more we can do to live our lives in the greenest way possible. And with 14% of the UK’s greenhouse gas emissions coming from home heating, heat pumps are a great place to start.

Want to be a heat pump pioneer?

We're bringing you something exciting. We’re inviting customers to test out a special heat pump offer. To find out more, register your interest and we’ll let you know when we're installing in your area.

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Sources and references:

1 Savings of £210 are based on the following comparison: a gas boiler running at 90% efficiency (as per the national average for A-rated boilers) with an annual consumption of 11,500 kWh at 5.75p/kWh, and 77% of consumption used for heating and hot water, versus an air source heat pump with a Seasonal Coefficient of Performance (or efficiency rating) of 4 and an annual consumption of 1,992 kWh at 15p/kWh with the Heat Pump Plus add-on.