6 Things to Know Before Buying a New Boiler Re March 6, 2020

6 Things to Know Before Buying a New Boiler

Worcester Bosch 8000 Life Style

Are you buying a new boiler soon?

If your boiler is acting up more than a two-year-old being dragged out of a sweet shop, then it’s time to consider a replacement. For your boiler, not your two-year-old! 

There comes a point in every boiler’s life where they begin to cost more than they are worth and it becomes unfeasible to keep spending on repairs. But before you strike out online and buy the first boiler you see, it’s worth learning a bit more about what to look for in a new boiler, after all, you’re going to be together for some time.

It’s worth mentioning at this point to keep an eye out on whether installation is included in the price. All WarmZilla boiler prices include installation from a Gas Safe engineer. Some people think they are getting a great price only to realise they have to arrange fitting on top! Many engineers only operate on a supply and fit basis, WarmZilla included, so if a price seems too good to be true, it probably is.

It’s also worth noting here that WarmZilla offers a ‘Best Price Guarantee’ on our new boilers. If you find a cheaper like-for-like quote elsewhere, let us know, and we’ll beat it by £50.

Gas boiler ban

We’ve covered the gas boiler ban in-depth in another article, but it’s worth mentioning here as we do get asked whether it’s worth buying a boiler with the upcoming ban. 

To begin with, the gas boiler ban in 2025 only applies to new build homes. It doesn’t apply to any other home, so it’s fine to replace your gas boiler with another gas boiler.

Until there is a viable alternative available that’s affordable to the public then gas boilers will continue to be chosen as the number one heating method for homes in the U.K. If you have a spare 10k to upgrade your heating system to a heat pump and to retrofit your home with advanced insulation then great, but for most people, this isn’t an option.

Exciting trials are currently being run using hydrogen as an alternative fuel source. This would enable the current gas network in the U.K to be utilised and very similar boilers to be used, both in cost and design. Hydrogen is a carbon-free fuel source so it’s more environmentally friendly than any other options available currently, as renewable energy sources cannot meet our energy requirements.

A three-year study is currently underway by Hy4Heat, testing to see if hydrogen is a viable and safe alternative fuel source that could be used in the UK.

Choosing the right brand

When choosing your new boiler it’s important to choose a trustworthy brand. One way of identifying a trustworthy brand is what awards they’ve won. Worcester Bosch for example, have won the Which? Best Buy boiler for the last ten years. A sure sign that they are producing reliable boilers. It also shows that they have been around for a while, so if you have a ten-year guarantee, they will still be around in ten years time to honour it.

We have seen many new boiler manufacturers popping up and then disappearing. Be careful with the brand you choose and pay attention to the guarantee length. If a manufacturer is comfortable offering a ten-year guarantee then that usually means that they don’t expect it to break down in that period of time. If it does then you have the peace of mind in knowing it’s covered.

According to a Which? Survey, the average cost of a boiler repair is £210, so it’s worth going for a reliable boiler that will serve you well for the next 15 years. You may save a couple of hundred on the initial purchase price but that’s just one repair job in the future and you’re out of pocket.

“If you choose the most reliable brand of boiler, according to our survey, an impressive 63% are likely to still be fault free after six and a half years. Get unlucky and pick the least reliable brand, and this falls to a disappointing 45%”


WarmZilla currently offers Ideal and Worcester Bosch boilers as we feel they are reputable companies that have been around for a long time and they are both award-winning manufacturers for both the product and their customer service.

Choosing the correct kW output for your home

When we talk about kW output with boilers it basically means the boilers power to supply your home with heat and hot water. The bigger your home, the more kW output you will require to supply it with heat and hot water.

We’ve covered ‘choosing the correct kW boiler’ in a previous article because we’re helpful like that, but if you don’t have time to read that article then here is a short breakdown.

The easiest way to calculate the kW boiler you will require is to complete the WarmZilla Survey. Answer a few simple questions about your home and we will recommend a selection of boilers that offer the perfect kW for your home. We do all the hard work so you can focus on choosing the right boiler.

The only thing to consider would be if you plan on extending your home in the future or if you plan on converting garage or loft space into living space, as this will increase your heating demand and you may want to oversize your boiler to compensate.

If you would like to speak to someone about your boiler size then get in touch with us. You will speak to an experienced Gas Safe engineer who will be able to advise you on your requirements, get in touch with us today

Understanding your current boiler type

There are four main types of boiler available, it’s important that you are able to identify what type you have so you can get an accurate quote on replacing your old boiler.

Combination boilers
More commonly known as combi boilers, they are the most common boiler installed in the U.K as they are easy to fit, cheap and they don’t have any additional water storage tanks in the airing cupboard or loft. Combi boilers heat water on demand from the mains supply so they are energy-efficient.

Heat-only boiler
Also known as regular, conventional, traditional or vent boilers. Heat only boilers are the most difficult to replace as they have both a hot and cold water storage tank. Most people choose to switch to a combi boiler when replacing a heat-only boiler as you can reclaim some space back in your home.

Back boiler units
Back boilers are tough old beasts, they last around 25 years but they are extremely inefficient and will be costing you money on your heating bills. They are located behind gas fires, where they quietly go about their inefficient business. It is harder to remove a back boiler (usually a two-day job) and incurs a higher installation cost. You will see a reduction in your heating bills and your new energy-efficient combi will be much better for the environment.

System boilers
System boilers are suited for homes with a high demand for hot water. System boilers are more suited for this as they have a separate hot water storage tank, so they can provide hot water to two bathrooms simultaneously. They have the disadvantage of a storage tank and the heat loss that occurs from that tank, no matter how well insulated it may be.

Now that you understand how to identify your current boiler type you are ready to move on to the next point. Proceed.

Getting an unbiased opinion on boilers

Everyone has an opinion on boilers. Many engineers disagree with each other about what boilers are good and which aren’t. One engineer will say Baxi is the best while the next may say they are rubbish. 

Keep in mind that each engineer usually gets a kickback from the boiler manufacturer they fit and they will likely steer you toward the boiler they get the best kickback from. There’s nothing wrong with that, they probably fit the boiler that they find most reliable and easy to install. Just be sure to do your own homework and find the boiler brand that’s right for you. 

We’ve reviewed all the best boiler brands for you, so you don’t have to!

What extras can save you more money

In addition to having a new energy efficient boiler installed, there are also other ways you can save money on your heating bill.

Smart thermostats

With every WarmZilla boiler installed we include a smart thermostat. This is a device that’s connected to your boiler that allows you to control the temperature of your home from your smartphone/app or voice-controlled device (Alexa/Google Nest).

Smart thermostats can learn your heating habits and heat rooms as and when they are occupied, so if you only spend a small amount of time in your dining room then it will learn to not heat that room other than meal times.

Tado says that its smart thermostat ‘will pay for itself within a year’ by reducing your heating bills by up to 31%. Netatmo claims that its smart thermostat will reduce the energy you use by 37%.

Smart thermostats give you more control over your heating and allow you to further reduce your heating bill and environmental impact.

Thermostatic radiator valves

In a similar way to smart thermostats, thermostatic radiator valves give you more control over your heating. Traditional radiator valves are either on or off, thermostatic radiator valves allow you to change the temperature dial for each radiator.

If you have a room that’s always hot then you can turn the temperature down and save money. Likewise, if you have a room that’s always cold you can increase the heat and get it to the right temperature.

By giving you more control over your heating you can lessen the demand on your boiler in certain rooms, which will take some unnecessary strain off your boiler and allow it to live a longer and fuller life.

We hope that this guide has been useful to you in your quest to find a new boiler. If you have any questions please get in touch with us and we’ll be happy to advise you. We wish you luck on your journey to find the perfect boiler.

Boiler size is measured in kilowatts (kW). A kilowatt is a unit that defines how much energy your boiler outputs in the form of heat.

The only time you would oversize your boiler was if you were considering an extension, converting a room into an en-suite, adding another shower or adding additional radiators into your property. Basically, anything that would increase the hot water or heating demand from your boiler.

There are 6 things to keep in mind before buying a new boiler; 

    1. Gas boiler ban
    2. Choosing the right brand
    3. Choosing the correct kW output 
    4. Understanding your current boiler type
    5. Getting an unbiased opinion on boilers
    6. Additional features that can save you more money
  • April 18, 2023, 11:45 am

    This is very informative, especially since I am planning to replace my old boiler soon. These tips have given me a better understanding of what to expect when choosing a new boiler for my home. I also found another helpful article on boiler replacement costs by PlumbTech, which has given me a better idea of the expenses involved. Thanks for sharing!

  • April 19, 2023, 10:16 am

    We are glad you found this informative, and look no further than WarmZilla when replacing your boiler 🙂

  • May 10, 2023, 11:14 am

    6 Things to Know Before Buying a New Boiler” is an incredibly helpful resource for anyone considering a boiler purchase. This concise guide offers a wealth of knowledge, ensuring buyers are well-prepared for their decision. It covers crucial aspects like fuel type, efficiency ratings, heating capacity, and installation requirements, empowering readers to make informed choices. The article’s clarity and succinctness make it easy to understand, even for those unfamiliar with boilers. Additionally, the inclusion of cost considerations and maintenance tips adds tremendous value. I highly recommend this article to anyone embarking on the boiler buying journey – a must-read for a stress-free purchase!

  • May 11, 2023, 11:23 am

    Thank you for the great feedback. We set out to make everything as pain free as possible and provide the most useful and accurate information.

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