Why you should plan for your boiler's replacement at every stage of its life

With the summer in full swing, your boiler breaking down might be the last thing on your mind.

But whether your heating system is newly installed or approaching the end of its life, taking time to plan ahead in the warmer months is a good way to avoid overpaying or being forced into a snap decision by an urgent boiler replacement when the time comes. 

Avoid a costly call out in the depths of winter and put together a plan for what you’ll eventually replace your boiler with, even if that’s a long way away. Forward planning can open up a wider range of options and make sure you’ve got the right funding in place, especially if you’re interested in low-carbon heating options. It also gives you the opportunity to make other improvements to your home that will help pave the way to a lower-carbon, cheaper-to-run future.

Wherever you are in your boiler’s lifespan, our free personalised energy planning service will show you where you can make improvements to your home’s energy efficiency and how much it will cost. Try it out and start your home’s tailored energy plan: Use our home energy planning tool.

Why you should avoid a last minute boiler decision

If your boiler unexpectedly breaks down and needs replacing, as happened to a third of boiler owners in our last survey*, you’ll need a replacement as soon as possible. Especially if it happens when it’s freezing cold, leaving you with no time to make a well-informed replacement choice and consider all your options. 

In the same survey, 14% told us they would consider swapping to an air source heat pump for their next heating system.10% told us they would consider a ground source heat pump, 7% a biomass boiler and 16% a hybrid heat pump and boiler system.

Combining an efficient heat pump with an energy tariff that discounts the energy used to run it can make heat pumps a temptingly cost-effective choice, as our research has found.

Read more: use our calculator tool to see how to maximise your heat pump savings with a specialist tariff in our guide to air source heat pump costs and savings

But installing low-carbon tech isn’t an overnight decision you can make when your boiler has already packed up. With longer lead times, and considerations about optimising your home’s set up - perhaps with some additional insulation or other home improvement updates - it’s worth putting a plan in place well in advance of needing a new boiler in a pinch. 

Even if you are planning a like-for-like boiler replacement, keeping it well maintained and having a succession plan in place will mean you’re set up as best as possible for a smooth transition. You'll know how you're going to pay for it and who will be on hand to carry out the work.

Here are our top tips, depending on your boiler's current condition:

1) If your boiler is new or in good working condition

You’d be forgiven for forgetting about your heating system once it’s newly set up and working well. But it’s a good idea to check the small print of your boiler’s warranty, which more often than not will require you to have an annual boiler service to remain valid. 

Even well working boilers may not be operating at their best, most efficient potential. During a boiler service, your engineer can set yours up to make instant energy bill savings by making the most of its settings and features. 

The summer months, when heating engineers are less busy, are a good time to book in a service. Get our top tips for making the most of your appointment, and find out how much you can expect to pay, in our guide to getting the best boiler service.

No matter what heating system you have, you’ll save money on your bills by keeping the heat you generate inside your home. If your boiler is still in its early years and you’re not worried about needing a replacement any time soon, it’s a good time to put your savings towards other home improvements that will lower your bills by making your home more energy efficient. You’ll start to see a return straight away, and you’ll also be future proofing your home so that it’s optimised for a low-carbon heating system in the future.

Insulation

• Loft insulation is one of the best - and most affordable - places to start when it comes to improving your home’s energy efficiency.
• Our guide to how to buy loft insulation takes you through the options and costs, plus explains what you can DIY yourself with a little know-how, and where you'll need to ask an expert. 
• Insulating walls and floors are bigger, more disruptive jobs, but can have big rewards if you’re in a position to make these updates. If you’re having other building work done, it’s worth factoring it in at this stage to minimise disruption and make your home improvements more cost effective. Head to our guide to how to insulate your home for a look at how to take a fabric-first approach to your home’s heating. 

Double glazing

• It's an expensive job, but updating your windows will see instant rewards, making your home cosier in winter and keeping it cooler in summer. It will warm up quickly and for longer when your heating is on, making your home cheaper to heat. You'll also benefit from better sound insulation.
• Get started with your guide to how to buy double glazing.

2) If your boiler is starting to develop minor faults

If your boiler is starting to age, it’s even more important to keep up regular servicing and maintenance to keep it going as long as possible. Because heating systems are so expensive to install, it’s rarely cost-effective to replace a boiler ahead of its time. You’re better off making sure you have some savings ring-fenced for repairs as and when you need them. 

Our research consistently finds that on the whole, you’re better off paying ad hoc for boiler repairs, rather than taking out insurance policies that can have spiralling premiums. But in some cases - if your boiler is particularly unreliable, for example - you might prefer the peace of mind that comes with a policy. You might also get it as part of packaged deals with other home or contents insurance, so see whether you are entitled to anything through other policies you have to make sure you’re not paying twice.

Our guide to how to choose the best boiler cover explains whether you need it, and how much it costs. 

For ad hoc boiler servicing and repairs, it’s worth choosing a boiler engineer you can trust. Having someone on hand who you can rely on, who knows your home and your system already, can be an invaluable resource as your boiler ages. 

Which? Trusted Traders vets local traders and makes sure that they have all the right certifications and credentials. Check past customer reviews and find a heating engineer near you at Which? Trusted Traders.  

Or, see our ranking of bigger, national boiler servicing firms, along with tips for what to ask about, in our guide to how to get the best boiler service.

Planning ahead for your next heating system

At this stage in your boiler’s life, it’s really worth making a plan for what might come next. 

If you’re likely to want another boiler, bear in mind that this will be a big expense. While financing options are available, it’s always best to pay up front if you can, so it’s a good time to start ring-fencing some savings so you know you have them ready. Gradually building up a dedicated savings pot means you won’t be caught off-guard by a big bill later on.

Our guide to how much a new boiler costs talks through the options. Or head to our guide to the different types of savings account explained.

If you’re interested in switching to a low-carbon heating system such as a heat pump, or a hybrid system, this stage in your boiler’s life is a good time to start researching what is on offer - in terms of the options that will best suit your home and the routes to financing. 

Many UK homes are heated by wet central heating, which circulates hot water through pipes that’s been heated up by a fossil fuel-powered boiler. But there are lots of other models out there, all of which have different pros and cons for different types of home. You can also put together hybrid systems that use a variety of technologies for different things, in different parts of your home, or at different times of year. 

Read more about: the different types of home heating system.

Talking to an expert about what could work for your home in the future can be invaluable. If you have a forward plan in mind for building work you might need and what you might expect to spend, you can do the work gradually as and when it suits you. Plus, you can keep an eye out for any relevant grants or discounts that might help with costs.

Upgrading your central heating

• Air-to-water heat pumps are the most common type installed in UK homes. They operate by passing water through your central heating system, so can be most closely compared to a typical boiler system. However, they tend to heat water to lower flow temperatures than boilers. That means that, while it’s not essential, heat pumps can be more efficient to run if you have large heat emitters (i.e. radiators) throughout your home.
• You can get an assessment at any time to see whether your home’s radiators are up to the task. If they need to be upgraded, you might choose to do this ahead of time to spread out the costs.   
• Wet underfloor heating is, in essence, simply turning your floor into a very large radiator that runs at a low flow temperature, so it can pair very well with a heat pump system. It’s expensive to install, but if you are doing other renovation work it could be a good time to consider installing it both for future-proofing and to make your home cosier straight away. 
• Read more in our guide to wet underfloor heating, including how it works, installation and running costs, and testimonials from homeowners who have had it fitted.

3) If your boiler is nearing the end of its life

By the time your boiler is showing signs that it might not last much longer, or if it’s particularly old, you should have a plan in place for what comes next. 

Find out more: 5 signs you might need a new boiler

Research your options, and make sure you have a heating engineer who you trust on hand.

If your next system is going to be a boiler, head to our guide to how to buy the best boiler, think about your boiler costs and see our ranking of the best boiler brands. 

We don’t recommend replacing a functioning boiler before its time. But if yours is unlikely to last the winter, having a plan ready will spare you the chaos of a last-minute decision.

Replacing a boiler with a heat pump

If you’re interested in making the switch to a heat pump, you’ll need to get prepared earlier than you would do to buy a new boiler. A like-for-like boiler replacement often only takes a few days, whereas a heat pump is likely to take a few weeks. If your boiler is on its last legs, it’s sensible to start the process before it becomes an emergency.

Look for local heat pump installers that come well recommended and ask for a selection of quotes, as you would for other home improvement works. Some energy companies and banks offer deals on heat pumps and installation. In order to access the government’s Boiler Upgrade Scheme (BUS) grant, you’ll need to use an MCS-registered engineer. The grant offers a discount of £7,500 on the upfront price for homeowners in England and Wales. The Scottish government also offers a similar scheme.

Read more on: air source heat pump costs and savings, which includes our heat pump running costs and savings calculator. Plus, find out how to access the government’s Boiler Upgrade Scheme.

Generally, you'll need space outside for an external condenser unit (roughly 1m x 1m x 2m), plus one metre clearance for air flow. Inside, the heat exchanger takes up about the same space as a gas boiler. The closer you can place this to the outside unit, the better. Integrated systems are available, which combine the heat exchanger and hot water cylinder into one unit, which is roughly the size of a fridge-freezer. Otherwise, you'll need a separate hot water cylinder too.

It’s possible to install heat pumps in flats and terraced houses with less space, though this might come with additional challenges. A good installer should be able to let you know your options and what, if any, work your home might need to get set up. For small flats, particularly those that already have electric heating and hot water, an air-to-air heat pump might be a good choice, though these aren’t currently covered by the BUS grant. 

See testimonials from Which? members who have had heat pumps installed in a variety of different homes, and their opinions (both positive and negative) in our guide: what it’s really like to have a heat pump.

Head to Which? Trusted Traders to find vetted local heat pump engineers near you. You can also use the MCS Register to find certified installers of heat pumps, solar panels and other green tech in your area.

Use our personalised home energy planning service

No matter where you are in your boiler’s lifespan, if you're interested in making your home more energy efficient it can be tricky to know where your money is best spent and what types of installation would benefit your home's specific requirements. That’s where our home energy planning tool can help. It cuts through the confusion, giving you information tailored to your property. Using data you input, as well as your EPC reports and other specifics, the tool will let you know how you can reduce your energy bills and how much it might cost upfront. 

You can get started with a plan and make any initial updates when your boiler is still working, so that you know you're well set up and ready to act when you do need a replacement.

Find out more and try out our home energy planning tool to start your personalised plan.

*Our research: May 2024 UK general public online survey of 10,028 people who are responsible for the maintenance of their boiler and our May-June survey of boiler engineers.