Home Improvement

Top Tips for Buying a New Boiler

So, you’ve finally decided to bite the bullet and invest in your new boiler. It may be that your old boiler has broken down and is now beyond repair, or it may be that you are looking to get a new energy efficient one to reduce your gas bills.

Either way, this means it’s time to wave goodbye to your old faulty boiler and replace it with a brand new A-Rated model. In this article, we’ve provided you with some tips and advice to help you successfully choose your new boiler.

So, if you:

  • Are considering to buy a new boiler;
  • Don’t know how to choose a new boiler;
  • Are confused with different types of boilers.

Then keep on reading!

Table of Contents:

Research beforehand

There are some key factors you have to take into account while researching the different types and boiler brands.

As a general rule, if your boiler is more than ten years old, even if it seems to be working well, it could be the time to invest in a newer, A-grade high-efficiency model.

ErP efficiency

ErP stands for Energy-Related Product Directive and signifies how much energy a product consumes throughout its lifetime. In the UK, it replaced a well-known SEDBUK (Seasonal Efficiency of Domestic Boilers UK) rating system. The ErP rating classifies the energy efficiency level from the lowest (labelled with the letter G) to A+++, which is the highest level of energy efficiency.

Your boiler efficiency is determined by how much fuel it uses and converts into energy and how much power is wasted in this process. From April 2018, new legislation requires all boilers in the UK to have at least a 92% energy efficiency rating in their fuel use, but you should look for models as close to 100% as possible.


The quieter the boiler, the more likely you can install it anywhere without worrying that it will wake you up. Your best bet is to get a boiler that has a noise level of 50dB or less. That way, even on the echoey attic it will not make a lot of sounds. 


This measures how much energy your boiler can use to heat water for your home. For a small apartment you won’t need a big boiler, therefore give your preference to a smaller boiler model. Three or four-bedroom homes will need a boiler with a heat load of 24 to 30 kW, while larger homes may require 35kW or more.

Nitrogen oxides 

Nitrogen oxides (NOx) refer to increasing emissions of nitric oxide (NO) and nitrogen dioxide (NO2) caused by combustion of fossil fuels. Domestic gas boilers are responsible for 14% of the environmentally harmful emissions in the UK, hence the government has decided to undertake certain measures to reduce the level of polluting emissions. Therefore, from September 2018, it is mandatory not to exceed the level of NOx emissions of 56mg/kWh for gas and LPG boilers. For oil boilers, the maximum that is allowed is 120 mg/kWh. However, if you would like to contribute to the environmental well-being, choose a boiler with a NOx emissions level of up to 30mg/kWh. 


The size of the boiler system varies depending on your property’s size and the number of radiators you have. If you do not have a lot of space for a hot water tank, then you may give your preference to a combi boiler or an electric one. 

You may also like:
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Choose the type of boiler

From old back boilers and a sealed system to gravity and combination boilers, the type of boiler suitable for your property will depend on several factors. To help you make the right decision, we have included the main types of boilers with their advantages and disadvantages:

Combi boilers

Because of the generally low installation price, compact size, and high efficiency, this kind of boiler became one of the most preferred types of boilers among UK households. Instead of having a water cylinder to store hot water, they are directly connected to the main water supply. When you turn on a tap, the boiler is triggered and it heats the water instantly.

When searching for a combi boiler, you might stumble on the following types:

  • Gas combi boilers – The perfect option when your home is connected to the main gas network.
  • Oil combi boilers – An alternative solution for properties that do not have access to the gas network but require installation of an outdoor oil tank.
  • LPG combi boiler – A right solution for homes without a gas supply. LPG is considered to be more environmentally friendly because it generates less harmful emissions compared to the other two. It’s equally efficient to the gas-powered boilers. 

Pros and cons of the combi boiler

  • Serve as a water heater and a heating system at once;
  • Requires less space because it doesn’t need a hot water cylinder or a pump;
  • Lower installation price compared to the other types of boilers.
  • If you turn multiple taps on around the house, the pressure may go down;
  • As the water is heated on demand, it may take a few seconds to heat up, resulting in wasted water;
  • In case of a breakdown, they don’t have a backup immersion heater.
To boost your system, you can also consider having a Megaflo fitted. Megaflo system ensures a strong water flow – so you can have a nice, full pressure shower.
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Regular boilers 

Regular boilers, also known as “traditional” or “conventional” are ideal for homes with an already working traditional heating system and a hot water cylinder. These boilers also need to be connected to cold water tanks in the loft area to supply the hot water cylinder with water.

A regular boiler is an excellent choice to replace your old unit with if you already have an older radiator system. The reason for this is that system and combi boilers deliver water in higher pressure and this may cause problems for your radiators.

Pros and cons of the regular boiler

  • Suitable for properties where a lot of hot water is used at the same time;
  • Suitable for properties with more than two bathrooms;
  • You can add an immersion heater in case if your boiler breaks;
  • Compatible with solar heating systems.
  • If you have a small property, space might become an issue;
  • You have to plan when to heat the water;
  • Your hot water is limited to the capacity of your hot water cylinder;
  • The installation price is higher compared to the other boiler types.

System boilers

They require a hot water cylinder but the main heating elements are built into the boiler. The system boiler doesn’t require water tanks in the loft which makes it a good idea for properties where free space is an issue. These boilers are compatible with solar heating systems. They take their water supply directly from the mains, like a combi, then heat it and store it in a hot water cylinder, like a conventional boiler.

Pros and cons of the system boiler

  • Good for properties with more than one bathroom;
  • They can provide a constant supply of hot water even when all taps are open;
  • There is no need for cold water tanks in the loft, therefore, it reduces the risk of leaks;
  • They contain built-in elements that make the installation easier.
  • It takes up space for the installation of a hot water tank or cylinder;
  • To prevent energy waste, the hot water tank requires good insulation;
  • You have to heat the water in advance;
  • You have a limited amount of hot water.

Create a budget

For most people, the budget dictates their choices. Therefore, it is essential to be clear about how much you are ready to spend on a new boiler. The price of a new boiler will depend on several factors: 

  • brand; 
  • type; 
  • fuel; 
  • size of the boiler you want for your property; 
  • installation costs. 

The price of a new combi boiler varies between £700 and £2000, depending on the boiler power that is required for your property;

Conventional boilers that are available on the market have a price of £650 and go up to £1800 for a unit;

The prices of system boilers range between £700 and £2200 depending on a model and a brand.

Check if you are eligible for financial support

Ask your energy supplier if there are any offers in your area that can help you. There are various programs and schemes intended to help people with low income or those who wish to save money. Pay a visit to the Energy Saving Trust website to see whether you are eligible for any type of discount or grant. To learn more about the ECO scheme, and if landlords and pensioners qualify for a free grant, read this helpful boiler grant guide.

Choose a technically competent installer

When choosing a new boiler, it is equally important to choose a proper installer. A poorly installed boiler can be insufficient and highly dangerous. Professionals will ensure that your new boiler complies with the current building regulations and provide you with documented evidence, which is needed if you want to sell or rent a property.

  • Your friends and family can be a good source of recommendations; 
  • Do your own research through such independent sources as Trustpilot;
  • Always use the services of a qualified heating engineer. Make sure they are Gas Safe registered and check their credentials.
Proper installation of a new boiler can save you up to 40% on central heating bills annually. 

Get a quote

It’s always good to get a quote for your new boiler. For the gas and LPG boilers, the plumbing company must be Gas Safe registered. If you plan to install an oil boiler, it is recommended to check if the installer is OFTEC registered. Make sure that your company has carried out all the proper checks and covers any potential damage connected with installation.

Need a professional to install your new boiler?

Get a quote from Fantastic Services!

Add a valid postcode e.g. SE1 2TH

Are you ready to replace your old boiler with a new one?

With good research on the brands and types available on the market, you’ll surely make the right choice for your home. And the Fantastic Services team will be here to aid you in your endeavour. Get a quote today, and benefit from our professional installation with an additional one-year guarantee! You can also make use of the boiler cover service which includes annual boiler service and cover of repair costs and more.


  • Replacing your old and inefficient boiler will help you save money and reduce the harmful emissions caused by fuel-burning boilers.
  • Don’t attempt to install the new boiler by yourself. The installation can be performed only by Gas Safe registered specialists and accredited professionals, so this way the warranty given by the manufacturer will remain valid.
  • If you need a budget-friendly boiler with a low installation cost and no extra space requirements, a combi boiler is a right solution for you.
  • When improving your heating system, it’s a good idea to upgrade your radiators, as well. The sludge that has built over time can damage your new boiler system.

* This blog post was originally published on My-Plumber.co.uk website which is now part of Fantastic Services.

Image source: Iakov Filimonov/shutterctock.com

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