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Do you really need a boiler replacement?

Before forking out for a new boiler, make sure you really need one. Here's how to check if your existing one can be fixed, and what to think about if you do need a replacement
Woman looking stressed on the phone standing near a boiler

A new boiler will likely cost quite a bit of money – so first find out if it's truly necessary. 

January is the month that sees the highest number of boiler repairs, according to boiler installers Boxt. That's hardly surprising given the low temperatures we've been experiencing lately. 

If your boiler is playing up, and you think you might need a new one, there are a number of things you should check first. 

If you definitely do need a new boiler, here are your options for funding it, how to get the most out of it and how to get by in the meantime.


Worried about energy bills? Here are 10 ways to reduce your energy bills, plus our favourite expert tips for cheap ways to stay warm this winter


Check for common boiler faults that could be fixed

Rule out any faults that could be sorted out first. These include loss of boiler pressure, frozen condensate pipes and no power supply. 

Our guide to common boiler problems talks through what to look out for and how to get these issues fixed.

If it's a problem that requires a professional, or you can't work out what's going wrong, contact a Trusted Trader. All our Trusted Traders have been thoroughly vetted by Which?.

If you can't get hold of a Trusted Trader in your area, at least check that the engineer you call out is Gas Safe Registered, by searching for their name on the official list of registered engineers. 


Read more: Five signs you need a new boiler


Buying a good replacement boiler

Boiler in a room

If it's certain you do need a new boiler, ensure it's from a brand that gets good reviews. 

We've surveyed more than 10,000 people who have bought a new boiler in the past six years to find out which brands are most reliable, which are most prone to developing faults and which most customers are satisfied with. 

We also surveyed engineers to find out which brands they say make good-quality boilers.

Revealed: the best gas and oil boiler brands.

What to do if you can't afford a new boiler

There's no getting around the fact that a new boiler is expensive and needing to buy one can come as an unwelcome surprise. 

One option is to pay in instalments. Several companies allow you to spread the cost of your boiler across monthly payments so that you don't need to find all the money outright. For example, Which? Trusted Trader Heatable offers 0% APR for four years with no deposit needed. 

As with buying anything on finance, you should try your best to pay it off before your 0% interest-free period ends. Find out more about financing a new boiler.

If you're concerned you still won't be able to meet the cost of a new boiler, our guide explains how to get a free boiler or boiler grant if you're eligible. 

You can also talk to an energy adviser at Citizen's Advice on 08082231133 (lines open Monday to Friday, 9am to 5pm, excluding bank holidays). 

How to stay warm in cold weather

Young woman looking cold cradling a drink with a blanket around her legs

In the short term, if your boiler is broken and you're waiting for a fix or a replacement, do what you can to avoid getting too cold, particularly if you're more vulnerable as living in a cold home can harm your health

Layer up, close your curtains and roll up towels to make DIY draught excluders

Closing any blinds or shutters when it's dark can help stop heat escaping from your building. A recent study by the UK Blind and Shutter Association (BSSA) and the University of Salford found that 'typically windows are the weak point in a building and heat will always find its way to colder surfaces. To maximise the effectiveness of blinds, the smaller the gap between the sides of the blind and the window frame, the better'. 

You could also buy an electric heater to use temporarily. We've rounded up the best electric heaters that we've tested. 

This isn't a long-term fix though, as electric heaters are only really designed to provide a quick burst of warmth in a small area. Using an electric heater as a replacement for central heating would end up costing a lot more in the end. Central heating also offers a more stable temperature, which is ultimately more comfortable and convenient. 

You shouldn't keep an electric heater on overnight, either, as this can pose a fire risk. 

We've also put together the cheapest ways to stay warm in bed at night. And find a local Warm Space if needed, where you can spend time for free, or at low cost, out of the cold.

Make sure your new boiler is set up for maximum efficiency

Your boiler installer should do this for you in any case, but it's worth asking them about this and letting them know it's important to you. 

For example, your heating system needs to be balanced when your new boiler is set up, to make sure that all radiators are giving out the right level of heat.

Setting a lower flow temperature (if you have a condensing combi boiler) can save you money while still keeping your home warm, as it uses less gas to achieve the same room temperature. Nesta's interactive boiler temperature tool walks you through the process. How much you'll save partly depends on how well-insulated your home is and what size radiators you have. 

Heating experts The Heating Hub say that owners of Ideal, Vaillant and Worcester Bosch combi boilers could make further savings by turning off the pre-heat function (sometimes called Warm Start or Comfort mode), which is normally turned on when your boiler is first installed. The pre-heat function keeps some hot water ready in the boiler, reducing the time taken for hot water to come out of the taps. 

If you're prepared to wait a bit for hot water to come through, you don't need the pre-heat setting turned on. 

Every home is different, and your installer should fine-tune your boiler set-up to your individual heating system. Our guide to different boiler controls and how they can save you money when set up correctly, is a good starting point. 

If you can, consider a heat pump

Heat pump attached to an outside wall

If your boiler hasn't broken down, and you're not in an immediate rush, but are simply looking at your other options, you might be thinking about a heat pump. It's a more sustainable alternative to a boiler, but not without its complexities. 

Many of us will have to transition to heat pumps in future, and government grants of £7,500 are currently available. This will reduce the cost of a new heat pump considerably, although you'll still have to find some of the money, so this isn't viable if you're already struggling to pay for a new boiler. 

You'll also need to determine whether your home is well set up for a heat pump or whether you'd need to make other alterations, such as updating your insulation and radiators. 

Check out our guides to the government's Boiler Upgrade Scheme (BUS) and to heat pumps explained to find out more about applying for a grant and the steps you should take first to make a heat pump run efficiently in your home.