Heatsy’s Top Ten Tips For Buying A New Boiler

May 17, 2023

So your trusted old gas boiler has finally called it a day, or maybe you’re being prudent and planning for the inevitable day that you wake up to find old faithful has bellowed its last plume of carbon-filled smoke from the chimney.

Whatever the reason is that you’re buying a new boiler, it’s a big purchase that most of us will only make a couple of times in our life, so it’s safe to say that spending a couple of extra days to make the right decision is a good choice.

Buying a new boiler can be a complex and time-consuming process. There are many things to consider: where will you be installing the new boiler, what manufacturer to use, what installer to use, how much it will cost, and how efficient it is. That is all before we enter the complex and diverse world of modern heating controls.

All seems a bit too much, and the allure of a hot water bottle and an electric kettle starting to seem a bit more tempting? Don’t worry; we’re here for you.

Below we’ll share our top tips for when you’re buying a new boiler and some advice that should help to make the whole process a little less daunting.

1. Choose the correct installer

A good boiler installer or boiler installation company will give you honest and impartial advice based on your circumstances, your budget, and your preferences.

Try to avoid using a company or installer who is only approved by one manufacturer.

Think about when you want mortgage advice. If you ask the bank’s advisor, they’ll only be able to give you advice about that bank’s products and might even withhold information about another better-suited lender.

The sound advice is to try at least one independent advisor who will give you impartial advice about the whole sector, not just one particular lender.

This logic is precisely the same for boiler installers. If the engineer is only approved by one manufacturer, they will only advise you about their preferred manufacturer’s boilers.

2. Know your budget and stick to it

Like most industries, the heating industry has a wide range of products and prices for different scenarios. For example, you could pay £2000 for a very basic boiler that’s installed quickly and cheaply, or you could pay £5000+ for a top-spec boiler and the equivalent boiler installer.

Ultimately your budget is your choice, and only you will know what you can afford to pay versus what you want to pay. Our advice based on our experiences is that the cheapest quote isn’t always the best value, and generally if a quote is a lot cheaper than others, there’s usually a reason for it.

3. Don’t wait until your boiler breaks

Understandably many people try to hold off replacing their boiler until the very last minute. It is ok to wait if you don’t have a family who rely on the heating and hot water.

If, like most of us, the thought of going without a hot shower for a couple of weeks is terrifying, waiting until the last minute could be a very costly and disruptive mistake.

Dishonest salespeople disguised as boiler installers will often prey on you at your most vulnerable time. For example, if your boiler has broken down in the middle of winter and you’re desperate to get the heating on, you’re much more likely to accept the first quote and end up with something that’s poorly installed and overpriced.

4. Get a home survey

A new boiler installation is a significant home improvement project. It’s not just a white goods appliance like a washing machine or a microwave.

They’re not designed to be ‘plug and play’ installations.

Get it right, and your new boiler installation will protect you and your family from the harshest of British winters and give you free-flowing, clean, warm water for years to come. Get it wrong, and it could have potentially fatal consequences for you, your family, and even your neighbours.

Given the importance of your gas boiler in your everyday life and the potentially catastrophic consequences of getting it installed incorrectly, do you really think it’s a decision you should be leaving to an algorithm or an app?

The home survey is more than an engineer just measuring what boiler will fit where. A good installer will also want to learn about you, your routine, your hot water needs, what’s important to you, energy efficiency, or controlling your heating remotely.

There is much more to a professional boiler installation than simply finding out what will fit, and try as they may, computer programmers cannot yet replace the expertise of a human.

5. Get 2-3 Quotes

It is always a good idea to get more than one quotation for your new boiler installation, but not too many that you end up confused.

We advise 2 or 3 to be the magic number. It’s enough for you to compare a couple of options, but not so many that you spend weeks changing your mind and delaying a decision.

Having 2 or 3 quotes is more than just checking the price. It will give you a chance to meet a few different engineers and see how they work, and you can see how you feel about them, were they late, did they call ahead, were they polite and respectful, did they wear shoe covers, how flexible were they, how many options did they give you, what questions did they ask you, what questions did they let you ask etc.

6. It’s A Heating & Hot Water SYSTEM

Boilers are an important part of your hot water and heating system. But they’re not the only part. When replacing a boiler, it’s important to consider your system as a whole. If you’re removing a 15-year-old boiler, for instance, the rest of your system will likely have 15-year old components. This doesn’t mean you need to completely remove everything and start again. But considering what other components you have on the system, which may be old and on the way out, is definitely a wise move. Imagine how frustrating it would be if you’d just invested your money into a new boiler, and 6 months later you end up with more expensive repairs because you left old components on the system. It’s usually cheaper to get the components replaced whilst having your boiler replaced. Check any components that are looking old and get them replaced at the same time. Look out for things like rusty old radiators, damaged/leaky pipework and noisy pumps or zone valves.

7. The Boiler Is Only As Good As Its Master ( The Controls )

The Boiler Plus Regulation makes it mandatory to connect combi boilers to an control like outdoor weather compensation thermostat. But because it’s not required for other system types, many people cut corners in this area.

The question is – why would you buy a modern, intelligent boiler and connect it to old, inefficient controls? It’s like buying a brand-new car only to disconnect the air conditioning and cruise control.

Modern thermostats, like load compensation thermostats improve the way your house feels dramatically and help you use less energy by working smarter.

We don’t just mean the all-singing, all-dancing internet-controlled thermostats. Basic modern thermostats are still intelligent and smart. Another critical component of the heating system is the thermostatic radiator valves. Often neglected and forgotten about, new thermostatic radiator valves play a huge part in keeping your home comfortable and helping you be less wasteful.

Once a room reaches the temperature you set it to, the thermostatic valve will turn that radiator off and prevent it from heating the room further. This means the boiler has less water to heat up, making it cheaper to run.

This is one of these scenarios where if you didn’t make these changes, you’d never know what you’re missing out on. However, we’ve never come across a customer who invested that little bit more to get a higher level of control and said that they regretted it.

8. Please, Please, Please Clean Your System!

The UK has the highest rate of boiler replacements under 10 years old anywhere in Europe. The number one killer of boilers is the system they’re connected to not having a powerflush.

We often hear old heating engineers and customers saying ‘They don’t make boilers like they used to’  Well, they don’t. They actually make them much, much better. They’re safer, more compact, and a whole lot more efficient, the problem lies with the system, and the lack of a powerflush.

Buying a new modern boiler and installing it onto a heating system that’s probably been there since the gas board installed it in the ’70s is like filling a Ferrari up with diesel and complaining that ‘They don't make cars like they used to’

Radiators corrode and fill up with sludge and debris. This sludge and debris will make its way to your new boiler and clog up all the major components. Worst of all, manufacturers won’t honour their warranty if the boiler breaks down due to corrosion. So what can you do about it? When the new boiler is being installed, it’s really important to make sure your system is cleaned properly.

There are three common cleaning methods:

  1. Standard chemical flush - This should be completed as standard with all boiler installations. It involves adding a cleaning chemical into the system and allowing the system to run for a while to allow the cleaner to take action. The water is then drained out to a suitable place and refreshed until the system water is cleaned. Be aware this isn’t the most intensive clean. A lot of debris remains in the system ready to make its way to the boiler at a later date.
  2.  Magnetic flush - This is similar to a chemical flush, but involves connecting a device which has large magnets. The radiators are then agitated and vibrated to help kick up the debris inside. This debris is mainly made of steel, known as magnetite, so it will stick to the magnets as it passes by and is filtered out of the system. This is a better method of cleaning than the standard flush, but the agitation of radiators does come with some slight risks of leakage and damage.
  3. Powerflush - A power flush is a more intensive clean than the magnetic flush. This method involves using a large powerful pump which moves water faster and with more power than the standard pump on your heating system. The direction of water can also be changed which helps hit spots that usually wouldn’t get hit. You can also add a much a stronger chemical to the system to break down the debris and leave a clean layer of material on the inside of the system. This helps with the efficiency and performance of the system overall.

9. Listen To The Experts

When it comes to choosing a new boiler, it’s important to listen to the experts. We often get customers saying “I want a Worcester because my dad said it’s the best one to get”, or “we’ve been online and Which? say Viessmann is the best.” The reality is, there isn’t one boiler that is the best for all scenarios – different boilers suit different situations better. Anyone with a gas ticket can install a boiler. But that doesn’t necessarily mean they have a good enough understanding of heating systems to be able to make the right call for you.

Highly experienced central heating engineers have a different perception when it comes to helping you choose a boiler.

Drawing on a wealth of expertise and considering every aspect of the situation, they can provide a solution that’s going to give you the best performance and energy efficiency while helping your boiler live for as long as possible. Not listening to the experts means not getting an expert’s perception and just basing your decision on the opinion of someone who has been getting good results from their boiler. This might not suit your home and can leave you with a poorly performing system or even confused by how advanced the boiler is.

10. Compare More Than Just The Bottom Line

When people get quotes, most of them see one thing – the price. Whilst price is important, it’s just as important to know exactly what you’re being priced for.

Let’s say you have three quotes, one comes in at £1,500, another at £2,500 and the third at £3,500. When comparing these quotes, ask these questions: What are the differences and how has each company got to that figure? Are they all pricing for the same type of installation? Are they pricing for the exact same boiler? Is there any additional work on the estimate that the other hasn’t factored in? What type of system clean are they doing? One system clean takes an hour the other can take all day.

Once you know each company is pricing for the exact same job, you’ll be comparing apples with apples. Then, you can make a fair comparison between what each company has to offer. Some will charge more because they offer more value to you in the long run. They might have a larger team to offer better support in the future, for example or expensive systems to ensure nothing ever gets missed. Don’t rush into choosing the cheapest quote, without asking why. We’ve seen many people end up with sub-standard installations that need to be removed after a few years. It’s better to pay the right price once, than the wrong price twice.


To re-cap, the most important part of buying a new boiler is choosing the correct engineer to install it. A good engineer will give you honest advice and help you make an informed decision without pushing one particular manufacturer onto you.

Plan your budget before you start, if you want to stretch it but don’t have the cash readily available, you could consider finance.

Even if your budget is low you shouldn’t accept that you’ll need to receive a poor service or be treated worse, a good installer will have an option that allows everyone to be happy.

Don’t forget that your heating system may well be the root cause of why your boiler is broken in the first place and will almost certainly need some attention.

If your boiler is older, plan ahead so you’re not left in a situation where you feel pressured to make a rash decision in an emergency.

Always get a home survey, you can meet the engineer and begin to build a relationship. It will also ensure the installation is professionally planned, and not just thrown together based on a piece of code.

Lastly, get 2 or 3 quotes, compare more than just the price, compare what each quote includes and how the engineer made you feel.

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Please remember, we’re heating experts so if you need your boiler repaired, a new heating installation or if you’re struggling with anything we’ve discussed here feel free to get in touch with us now so we can see how our solutions might help you.

Thank you for reading.