New boiler replacement and installation information and costs
The complete guide to choosing a new boiler, from how much it will cost to how to make an installation as smooth as possible. Free top tips download
How does a boiler work?
A boiler provides hot water for central heating, taps and showers. In simple terms, it works by passing incoming cold water through a heat exchanger which makes it hot. This heat exchanger is kept hot through a burner, which is powered by gas (or oil). The gas is ignited automatically by an electric ignition switch. when there is a demand for heat.
Which are the best boilers to install?
Choosing a boiler to install can be a complicated affair and the best choice for you will depend on what type of boiler you’re replacing, your own usage patterns and your particular home. There are three main types of boiler to choose from:
Regular (Heat Only) Boiler
A regular boiler, also known as a heat only boiler, is common to older properties. You’ll know you’ve got one if you’ve got tanks in the loft, as these two tanks feed water into the cylinder and the so-called ‘open vent’ central heating system. They’re a good solution for larger properties where multiple users will be needing hot water at the same time — but they do take up a lot of space and homeowners can experience low shower pressures.
System boilers require a cylinder for storing hot water, however the major heating and hot water system components are built into the boiler itself, making it quicker and easier to install. In addition, there is no need for a tank in the loft for the heating, so it can be an option in a home with little or no loft space or where the space is earmarked for a conversion. System boilers are compatible with vented or unvented cylinders. A vented cylinder will require a storage tank in the loft, an unvented cylinder is connected to the cold main and delivers higher pressure at the taps.
Combi boilers are the most compact of all the options, as they completely eliminate the need for a separate water cylinder – producing hot water on demand from the boiler itself. They’re relatively simple to install, too, and are a great solution for average-sized homes which enjoy good water pressure. They’re not necessarily perfect for everyone, however. They struggle to cope with multiple simultaneous hot water demand and can supply disappointing shower pressures. On the plus side, because the hot water is only produced when needed, they are very energy efficient.
Off-mains Boiler Solutions
Some 4 million homes in the UK are located away from the mains gas network and as a result have to choose an off-mains alternative to a gas boiler. The most common choice is to use oil – many of the regular boiler manufacturers provide oil-fired options of their models, powered by an oil supply from a tank usually located in the garden. Oil prices are extremely volatile and not everyone likes the idea of relying on fossil fuels to heat their home. The other popular alternative is an LPG-fired boiler, which relies on bottled gas. Again, prices are relatively high for the fuel and you have to keep on top of deliveries.
There are some greener alternatives. The most popular solution is to opt for a heat pump, which relies on an electricity-powered heat exchanger extracting heat energy either from the air (air-source) or ground (ground source). They remove the need for a boiler completely but installation and product costs are significant, although some Government support is available through the Renewable Heat Incentive (RHI) scheme. Another option is to install a boiler powered by biomass fuel (typically wood pellets).
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When is the Right Time to Replace your Boiler?
Replacing a boiler is almost always a distressing purchase, meaning you’re forced into action by the existing system failing – and being prohibitively expensive to repair. Boilers typically last around 20 years but some last much longer (and some give up much sooner). If you’re having other home improvements carried out it might be a good time to combine the disruption all at once.
One of the key reasons to change is that your existing boiler is likely to be less efficient than a potential new replacement. Many older boilers operate at between 50-70% efficiency (meaning 50-70% of the energy going into the boiler is converted into heat) whereas modern boilers have to be at least 86% efficient. As a result, you will save money in the long term with a boiler replacement.
Another key deciding factor is the availability of spare parts for repair. As the boiler gets older the manufacturer is less likely to stock spares, making repair much more difficult.
How to Get a Boiler Installed
When it comes to boiler installation, there are three main options. The first is to use one of the big energy suppliers who provide their own supply-and-fit service – allowing homeowners to choose from a (fairly limited) range of boilers and then have one of their installers install. The process usually involves a free visit from a ‘heating advisor’ who will provide a recommended course of action.
The second option is to use a large independent boiler and central heating installer. They tend to have a broader range of potential products to choose from and will send out an advisor (often chargeable, but discounted off a potential purchase) to give recommendations.
Lastly, the UK is blessed with a huge number of expert independent heating engineers and plumbers. These engineers will be able to visit your home and give you independent advice and a fixed price quote for the boiler installation. Of course, all engineers will have their favoured boiler makes but most will be able to offer several options at different price points.
There are several advantages to using a local heating engineer:
– You get to speak to the qualified gas fitter from the start of the process, so there are no surprises. Larger companies will often send a salesman to survey and quote and this may lead to problems later in the process.
– A heating engineer will be very reliant on his or her reputation and as a result is much more likely to provide excellent customer service.
– Critically, using this route means that the person installing the boiler is the same one who will service it – meaning they know the boiler well and how it was installed.
– As they usually have lower overheads, they can often provide keener prices than the bigger companies.
Grants that cover some, most or all of the cost of a replacement boiler are available under the Government’s Energy Company Obligation (ECO) scheme. This specifically targets people who own their own home or tenants who have the landlord’s permission, as well as those in certain situations in social housing. In order to qualify you must earn below a certain income level (currently £30,000) and also claim one of several different types of benefit. The amount you can claim depends on your circumstances. The boiler being replaced must be at least 8 years old and worse than 86% efficient.
What is the Best Boiler Brand?
Every installer has their own particular favourite brands – whether it’s Vaillant, Baxi, Viessmann, Worcester-Bosch, Ideal or any of the other dozens of boiler brands selling in the UK. In many ways when choosing a heating engineer you’re also often choosing the brand that they are loyal to as well – but there are differences. Boiler manufacturers not only offer different warranty lengths, different efficiencies and, of course, differing price points, but their reputations will differ according to heating engineers’ individual experiences of being called out to common faults, or difficulties in finding spares at reasonable prices, and so on. The best course of action is to consult several heating engineers during the quotation process to get their views.
What Size Boiler Should I Choose?
Before you choose a boiler, a heating engineer should properly survey the system to ensure the right size boiler is specified. The size of the output of the boiler (quoted in kW) is calculated by adding up the outputs of all the radiators in the house (radiator outputs are usually quoted in BTUs (1BTU = 0.29w, so a large 7000BTU radiator will output approx 2kW) and allowing extra for bathrooms. However, other factors do go into the calculation, which is why it’s important a heating engineer carries it out. Typically, an average size house will need a boiler in the 20-30kW range, a bigger property between 32-40kW.
Fixing a faulty boiler can be difficult and expensive. One of the great benefits of buying new is that manufacturers will offer a parts and labour warranty on the boiler, with the term varying between 2 and 12 years depending on the manufacturer and the model. As with any warranty, it’s worth checking the terms and conditions of the particular manufacturer’s warranty to make sure it’s actually worthwhile. Most warranties require you to have the boiler serviced by registered/approved engineers, which can in some cases add to the regular servicing costs. Don’t forget that a boiler is only part of a wider central heating system, so boiler warranties can be surprisingly limited in what they actually cover – and as a result many manufacturers insist on a deposit payment paid before their engineer visits which is refunded only if the work is covered under warranty.
Several companies offer central heating and boiler insurance, typically charging £5-10 per month. This insurance usually provides unlimited repairs (parts and labour) for a central heating system and includes the boiler. If you’re considering boiler insurance, make sure the excess is relatively low (typically in the region of £50) as a regular service should help you avoid most issues before they happen. Make sure too that the insurance company can provide 24/7 cover with speedy response – if your boiler does fail, you’ll need help quickly.
There isn’t a lot you can do to maintain your boiler yourself – keeping the casing clean is beneficial but hardly likely to make sure it works well. An annual service from a heating engineer is, however, a critical part of not just maintaining boiler performance but ensuring safety. A service will deal with any problems of pressure, ensure the boiler is burning correctly, that the flue is clear, connections and pipework are clean and sealed properly, and check for any potential wear and tear issues. A typical boiler service will cost around £100.
Choosing a Boiler Installation Engineer
Hopefully your boiler installer will be the same person who services your system for years to come – so unlike choosing many tradespeople, the heating engineer is likely to become a part of the family, visiting year in, year out and on the days when the system breaks down, too. As a result, it’s an important decision. Anyone working with gas must be on the Gas Safe Register (this replaced the old CORGI register in 2009). After that, the choice of boiler installer comes down to several key things. Are they relatively local – because they will need to come back and service the boiler once a year and it’s better to have an expert to hand if things go wrong? Do they have experience of different boilers, and can therefore provide you with different options dependent on your budget? Try and get quotes from three different engineers and meet them in person — so much of this long term relationship is based on trust.
The Importance of Controls
In many ways the effectiveness of the system will be not so much down to the boiler as how it is used – which means controls are important. Driving the system efficiently means not just reducing heating bills but also running the boiler at a smoother level – which means it is likely to last longer. For example, many people set their preferred hot water temperature too high – it needs to be heated to 60˚C to kill off bacteria, but typically a hot shower is around 40˚C, meaning that the hot water is mixed down with cold – a real waste. Also, try and co-ordinate a domestic hot water (DHW) load (usually lasting around an hour to fill a cylinder) with the central heating timing to ensure you’re not constantly powering up the boiler – your hot water shouldn’t be on constant demand every time someone turns a hot tap on. Smart controls such as Nest and Hive make minimising heat demand even easier.
Best Ways to Save on Your Boiler
Don’t scrimp on the boiler itself – but you can certainly help out with reducing installation costs. Remove any cabinetry yourself and ensure that the installer will not be spending valuable time sorting out clear access to the boiler space.
Time of the year – most heating engineers tend to be busy from September (as people turn on their heating systems only to find they don’t work) through to March (when heating systems are tired and liable to break after a heavy winter’s work). If you’re able to plan in advance, look to get prices for installation during Spring and Summer. Heating engineers are likely to be a bit quieter during this time and as a result might offer keener prices on installation.
What happens before the installation?
Before the day of the installation, an expert plumber/surveyor should arrange a visit to your property to review your current installation.
They will check the following:
- Your current boiler’s position
- Water pressure
- Number of radiators
- Position of the flue
- Number of bathrooms in your home
They’ll advise on the best boiler solution for your circumstances and identify the best location to house your new boiler.
Our expert Gas Safe registered Boiler Installers Steven Moorhouse & Aaron Clancy from Here 4 Heat Ltd have over 10 years of boiler installation experience. Read their top tips to ensure a successful boiler installation:
- There are very few boilers now that will last 20 years. In the South (a hard water area) we find that the average lifespan of a combination boiler is 12-14 years depending on the make. A heat only will last longer.
- Budget for the best boiler you can afford and make sure you get a good warranty agreement in place. Research boiler brands online and remember you can also check feedback reviews on Checkatrade.com for insights on their recommended installation companies.
- Consider booking your first service, there and then, after installation, to ensure your investment is kept in tip-top condition. Write the name and number of your engineer on a label and fix to a discreet part of the boiler so you can find it quickly in case of an emergency.
- Plan the best time to get your boiler replaced and remember that you will have to accommodate a day without hot water.
- While the engineer is hard at work, you don’t need to be at the property. An average boiler installation may take around a day or two to complete, so be sure to check when you need to be back at your home so they can talk you through how your new boiler works. This is really important as you need to know the essentials to ensure that you have a trouble-free period after your new boiler is in situ.
- As well as conducting the installation of your boiler, the engineer may also need to carry out what’s known as a power flush. This is an additional process which simply gets rid of any debris that may be lying inside the system after the boiler has been put together.
One final tip: New boilers are efficient because of their electronics but they are not as robust as the old cast iron units which basically only had 4 components that could go wrong. So remember to schedule in regular maintenance to avoid any problems.