Installing heat pumps might help the climate, but do they fit in British homes?

The Coronation, Eurovision, and summer holidays are on the horizon. Replacing your central heating is slipping down the priorities list. But if your boiler is on the brink, now might actually be a great time to start considering a heat pump (before it’s two degrees again, said boiler breaks and you panic buy another).

I recently started to investigate the switch to a ground source heat pump to coincide with some planned renovation work. Like roughly half of the population, I knew very little about these systems, but was surprised by just how ‘green’ they are: they don’t produce any CO2 emissions at the point of use and the heat generated is four times the amount of electricity used in the process.

After hours of research and conversations with experts, I finally felt like I knew enough about how they work and what I would need to do to get one… spoiler alert, it’s not straightforward.

Here are some of the things you’ll need to think about.

Ground source or air source?

Ground source heat pumps absorb heat from the soil, whereas air source heat pumps absorb heat from the air. Ground source heat pumps are more efficient, but they require boreholes or trenches to be dug in your garden, meaning this option is ruled out for many, especially those seeking to minimise stress and expense.

For this reason, most people choose air source heat pumps (so I’ll focus on these).

Do you have space?

Starting outside, a typical unit is about one metre wide, one metre tall, and half a metre deep. The bigger the house, the bigger the heat pump. It will need at least one metre distance from any boundary walls for the development to be permitted. Bear in mind that the heat pump will make some noise when it’s running, so you might want to avoid placing it near a bedroom window. Most modern heat pumps are designed to be low-noise though, and are generally no louder than a gas boiler.

UK homes typically have combi boilers that generate hot water instantly, whereas heat pumps require storing hot water in a cylinder until needed. These cylinders can be large, comparable to a standard fridge, depending on the household’s hot water usage.

If you have a combi boiler, you’ll need to find space to install a cylinder, which may require sacrificing storage space. If you already have one, you may need to replace it with a larger one. Fortunately, a number of heat pump installers include a free house assessment as part of their service. It’s worth shopping around for one of those.

Could your home be better insulated?

Do you have loft and cavity wall insulation, draft proofing and double-glazed windows? The better insulated your home is, the less heat the heat pump will need to generate, and the cheaper it will be to run. Investing in improved insulation is often worth the upfront cost, as it saves on electricity costs over time.

Will my radiators need to be upgraded?

If you’re a bit of a heat geek, you might already know that the temperature of the water flowing into your radiators is known as the ‘flow temperature’. The flow temperature you need depends on factors like the radiator size, insulation and desired home temperature.

Higher flow temperatures make heat pumps less efficient and more expensive to run, so installers may recommend replacing smaller radiators with larger ones in order for the heat pump to run at a lower flow temperature. As with insulation, investing in radiator upgrades will save on running costs in future. So if you’re already planning home renovations, now could be the ideal time to upgrade your existing heating system.

How much would this all cost?

The average cost of a heat pump installation in a ‘typical’ home is £11,500, but with the voucher from the Government’s Boiler Upgrade Scheme the fee is generally reduced to around £6,500.

By comparison, a new gas boiler installation will typically cost £2,000-£4,000. There’s no way of sugar-coating this – for the foreseeable future, a heat pump is almost always going to be more expensive to install than a boiler.

How about running costs? Based on recent data, a heat pump works out as only £48 more than gas over the course of a year. However, the pump beats an oil boiler on running cost by £88 per year and an LPG boiler by an impressive £650.

So in summary, a heat pump is not going to actively save you much today if you have a standard gas boiler. But the energy crisis is prompting a reform in the energy market and we should expect to see gas prices increase and electricity costs fall – reducing the running costs of a heat pump.

It’s also worth noting that if you have solar panels (or are thinking of installing them) then they would likely allow you to run your heat pump for free, as well as massively cut your carbon emissions.

So, is it all worth it?

Whether or not a heat pump is right for you and your home will depend on many factors. The best thing to do if you are considering installing a heat pump is to talk to a local heat pump installer who can give you advice for your circumstances.

I know it may sound much more complicated than just sticking with a trusty boiler, but with the ban on gas boiler sales in 2035 approaching fast, it might be worth getting ahead and pivoting to a pump. One day soon, it could save you money, and cut your carbon footprint for the future.