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The Essential Guide To Gas Boiler Installation With All Heat UK.

The Essential Guide To Gas Boiler Installation

The essential guide to gas boiler installation covers everything there is to know about getting your gas boiler or heating system replaced. We cover the costs involved, the types of boiler available to you, the size required for different homes and which boilers we think are best on the market right now. Have a read below to learn everything there is to know about getting a new gas boiler installation with All Heat UK.

An Introduction to Gas Boiler Installation

The Boiler is the heart of your home, it supplies you with hot water and heat all year round, so when it comes to having a new gas boiler installed it only makes sense to want to know everything about the experience. Because having prior knowledge will help you make the best decisions, the team here at All Heat UK had a brainstorming session and came up with this 5 part series ‘The Essential Guide to Gas Boiler Installation with All Heat UK’

In this series we’re going to take you through the A-Z of boiler installation, we’ll discover the different types of boiler and help you decide whether a combi, conventional or system boiler is right for your property. Then we’ll highlight some of our favourite brands and guide you through an average gas boiler installation with All Heat UK.

So sit back, grab a cup of tea and let’s discover the ins and outs of gas boiler installation.

Table Of Contents

  1. 5 common Reasons to Get a New Gas Boiler
  2. How Long Does a Gas Combi Boiler Last?
  3. How Much Does A New Gas Boiler Cost?
  4. What Are The Different Types of Gas Boiler?
  5. What Size Boiler Do I Need?
  6. What Is The Best Combi Boiler?
  7. What Are the Best Gas Boiler Brands In 2021?
  8. How Much Is a Combi Boiler?
  9. How Much Does a Gas Boiler Installation Cost?
  10. A Full Breakdown Of Gas Boiler Installation Costs
  11. Who Can Install My Gas Combi Boiler?
  12. What To Expect From A Gas Boiler Installation From All Heat UK
  13. How Long Does It Take To Install A Gas Boiler?
  14. How Often Do I Need My Gas Boiler Serviced?
  15. 5 Main Benefits Of Having A New Gas Combi Boiler Installed
  16. Which is The Cheapest Combi Boiler?
  17. Which Is The Most Efficient Combi Boiler?
  18. Conclusion

5 Common Reasons to Get A New Gas Boiler

Below we’ve compiled a list of the 5 most common reasons you would want to replace your boiler.

  1. Mounting Repair Costs – Boilers like all other appliances can break down. However, if you’re finding that you’ve had multiple visits from your boiler engineer then the likelihood is it’s time for you to get a new boiler. Adding up call out fees and replacement parts can quickly become costly and only 2-3 visits from your local boiler engineer could soon mount to be as much or more than a completely new unit! Not only that, but as units get older the parts needed to fix them will become out of stock and hard to find overtime.
  2. Energy Efficient – All modern boilers have the energy efficiency rating of A, which means that they’re running at at least 90% efficiency. Now consider that a G-rated boiler can score as low as under 70% and I’m sure you’ll see how having a new gas boiler installed can have a positive effect on the overall energy efficiency of your home.
  3. Expensive Bills – With that better energy efficiency we just mentioned comes cheaper energy bills overall. Not only that but, modern controls allow you to have a greater control on your boiler than ever before, allowing you to ensure you never waste a penny.
  4. Safety First – As with all appliances the older they get, the more chance here is that they can have faults arise. If your gas boiler does have a failure such as a leak this can lead to fire, structural damage to your property or even loss of life! New boilers are much safer and in general are much less likely to go wrong.
  5. No Longer Under Warranty – As we’ll go into more depth with later on in this series, many modern boilers can have warranties that last from 2-10 years depending on the brand and model you choose. Having a valid warranty from the manufacturer means that if you experience a fault with your boiler within the amount of time you’re covered for, then the manufacturer will repair the boiler free of charge.

Here at All Heat UK we know how important it is that your boiler is working all year round. That’s why we offer a next day installation with any boiler of your choice! Click Here to visit our site and find out more! (Terms and Conditions Apply)

How Long Does a Gas Combi Boiler Last?

Generally speaking modern gas combi boilers can last upto around 15 years older, possibly even longer depending on the quality and model you choose. Another factor that most people don’t really consider when trying to understand how long a combi boiler lasts is how well the boiler is maintained and kept clean. A clean and well maintained combi boiler can last much longer than one that is just left to gather dust since it’s installation. Dust and grime can build up over time and cause faults with the unit.

Many modern gas boilers come with upto a 10 year warranty these days as well, taking this into consideration it’s evident that having a new combi boiler installed in your property if your old boiler is getting on in age, could save you money and potentially keep you from being out in the cold at the worst time.

In the next part of this series we’re going to take a look at the following questions ‘What Type Of Gas Boiler Do I Need?’, What Size Boiler Do I Need? And then we’ll take a look at the ‘Top 5 Brands Of gas boilers in 2021’ to aid you when making the decision about what boiler is right for your home.

How Much Does A New Gas Boiler Cost?

Many people like to break down the cost of their installation. So, knowing how much your boiler costs standalone is highly important. A new combi or system boiler can range between £500 – £900 for something that would be considered a budget model. While mid and upper tier ranges can cost from £900-£2000 depending on the size and brand of the boiler you choose.

What Are The Different Types of Gas Boiler?

There are three main types of boiler you can use to heat your home. System, Combi and Conventional. In this part of the article we’re going to take a look at each type to help you decide which boiler is right for you.

  • Systems – A system boiler is very similar to a conventional boiler, however more of the components of the heating system are built inside of the unit. They don’t require a tank in the loft and are often easier to install as a result. System boilers are a popular choice with those folks who have larger properties with multiple bathrooms where water usage is high. The fact that there aren’t any components in the loft with this method means you don’t have to worry about frosts causing leaks during the colder winter months.
  • Combi – A combi or combination boiler is very compact as it doesn’t use hot water cylinders. Installation of these units is usually very quick. Combi boilers provide hot water to both the central heating and the hot water taps from a single unit. Combi boilers are England’s most popular type of boiler installation as they are perfect for small to medium size houses. Another reason combi boilers are so popular is because they can provide hot water on demand instantly.
  • Conventional – Conventional boilers work great in areas that have a low water pressure as they can produce a greater flow rate than other central heating methods. A great choice for older properties where older heating systems may not tolerate the pressure of a closed system boiler. Another good choice if you have multiple bathrooms, but as a result does take up more space. Installing a conventional boiler is by far the most costly way to heat your home and is only recommended in the situations we’ve highlighted above.

What Size Boiler Do I Need?

Before we start to talk about what size of boiler you may require in your home, it’s important that we highlight the unit of measurement that boiler size is measured in. Boiler size is measured in kW (kilowatts) or to the laymen it’s measured in the amount of energy it can output rather than its actual size.

Generally the rule of thumb is the more hot water and heat your home requires the higher the output of boiler you will need, although, some other factors are at play in this equation as well. In the past homeowners would be advised to have a boiler that was oversized for their home to compensate for any heat loss, fortunately due to modern advances in boiler technology this is no longer required.

As we previously stated earlier in this article the combi boiler is by far the most popular choice for most homes across England. However, if you find yourself with multiple bathrooms or you have a larger home you may well find that a combi boiler just isn’t powerful enough to keep up. If this is the case you’ll be looking at either a system or conventional boiler but, you’ll need to keep in mind that both take up extra room and the conventional boiler needs to have a water tank in the loft.

Another factor you’ll have to consider before choosing a boiler that is right for your home is how many radiators there are to heat. An engineer will also take a look at the floor area of the building to calculate for the potential heat loss you could expect that allows you to choose a boiler of optimum size.

As we alluded to previously in the article the water pressure in your area will be another factor you’ll have to consider before determining what size boiler is correct for your home.

What Is The Best Combi Boiler?

When looking at the most popular boilers on the internet and after speaking to lots of our customers we can say that without a shadow of a doubt that the Greenstar i line of boilers by the folks over at Worcester Bosch.

The Greenstar i boiler comes in small and medium sizes. The Greenstar i comes with a user friendly control and upto a 10 year guarantee when your appliance is installed with a Worcester Bosch Accredited installer.

Not only that but, the Greenstar i has won the Which Best Buy award multiple times most recently in september 2020.

What Are the Best Gas Boiler Brands In 2021?

Now to cap this section of the article off we’re going to highlight our top 5 Best Boiler Brands for 2021.

  1. Worcester Bosch – Worcester Bosch are quite possibly the only name on this list you’ll recognise and with good reason. Worcester Bosch have received many Which Best Buy awards and not just for their excellent Greenstar i line either. Most of their boilers come with a lifetime guarantee of a minimum of 10 years, that just shows you the level of confidence they have in their products and quite frankly we share that confidence with them. Worcester Bosch are our pick here at All Heat UK for top boiler brand in 2021 and beyond!
  2. Ideal Boilers – Ideal are a British company that’s expanded greatly over the past decade or so. Ideal offer a range of differing warranties ranging from 2-10 years depending on the model of boiler you choose.
  3. Viessmann Boilers – Viessmann are a german company and the largest manufacturer of boilers in europe. Viessman are another company that regularly win Best Buy awards and the like as their boilers are known for their efficiency and have been known to last longer than some of their competitors offerings.
  4. Vaillant Boilers – Another name that screams ‘quality boilers’ in the industry is Vaillant. Their EcoTec range is fast becoming a favourite of homeowners across the country. Although they don’t have the same market presence as some of the others on this list, Vaillant offers a great support network and excellent warranties as well.
  5. Alpha Boilers – Alpha boilers are great for those who are working on a budget and are a popular brand with landlords as a result. Reviews all praise their aftercare support and they offer some great warranties too.

In the third part of this article we’re going to take a look at ‘How Much Does It Cost To Install A Boiler’ and find out exactly ‘What Should You Expect From A New Boiler Installation?’

How Much Is a Combi Boiler?

A lot of people like to break down the individual costs related to the purchase of a boiler and having the boiler installation. New Combi and system boilers range in price from around £600 – £900 for what would be considered a ‘budget’ model.

While a mid range model can cost around £1000 -£1500 depending on brand and premium Combi and system boilers can cost from £1000 upwards. Those who are looking at having a regular boiler installation can expect to see prices ranging from £500-£2000, just like the combi and system boilers there’s premium and budgets versions available.

How Much Does a Gas Boiler Installation Cost?

Boiler installation prices can vary a great deal depending on what area of the country you are in, the parts you may need and the complexity of the installation of the boiler itself. At the moment you can expect to spend anywhere from around £1500 -£4000 again a main contributing factor will be your area, however bear in mind that the more premium boilers may well come with more of a premium price tag too.

However, If you’re looking at having a like for like replacement on a mid price range combi boiler you could be looking at around £900.

Wondering how much it’ll cost to have a boiler installation with All Heat Uk? Visit Our Site to find out how little a NEXT DAY installation will cost.

A Full Breakdown Of Gas Boiler Installation Costs


The vertical flue works like an exhaust for your boiler to release condensation and various gases that need to be expelled from the unit. You’ve most likely seen these popping out from the side of an out house or the like in the past, although it isn’t unheard of for the flue to be located in the roof in certain circumstances. If you’re replacing an older boiler (models pre 2005) you may well find that changing the boiler flue will be required. This will likely be factored into your installation price, however in some cases it may be necessary for the engineer to price this job separately, depending on the complexity of the task.

Prices Range From £100-£600.

Plume Kit

A plume kit is used to extend the flue and adapt the outlets, in the case that the flues current outlets cause an hazard of some kind or that it comes too close to a neighbouring property. Plume kits often include bend pieces such as 45° and 90° bends that allow the Gas Safe Engineer to navigate around tight corners and such.

Prices Range From £90 -£150.

Gas Upgrade

Older models of boiler often used a 15mm piping, this doesn’t meet the current safety guidelines. In this case the 15mm piping will need to be replaced with the new standard of 22mm piping. In addition to this older piping often was constructed of lead and other materials that are either unsafe or don’t work with our current system. These days all pipes for gas fitted Combi boilers should be made of copper although other affordable metals such as steel are known to work just as well.

Prices Range From £250-£400.

Heating Controls

Another factor and certainly an important part of your boiler is the control unit. These days boilers have caught up with the times and all brands offer some sort of smart integration to their boiler lines. Smart heating controls can be everything from an lcd panel on your wall that allows you way more control than ever before to having an app on your phone that allows you to control the heat in your home wherever you are in the world. Smart Controls are an excellent way to further improve your homes energy efficiency, once you have a new combi boiler installed.

Prices Elsewhere Range From £100 – £350.


To many people the warranty can be one of the key selling features to the boiler in the first place. As we mentioned earlier some warranties can last upto and over 10 years, so when you consider that most boilers can last in the region of 15 years if they’re being taken care of then getting a boiler with an excellent warranty seems like a great idea.

Although the warranty doesn’t cost you anything persay, it does show you the amount of confidence that particular manufacturer has in their products.

Magnetic Filters

The magnetic filters work as a trap for any dirt or small particles of metal. The magnetic filter is designed to protect the surrounding pipework. This aids in prevention of leaks and damage. In most cases the magnetic filter will be factored into the price of your installation.

Prices Range From £80-£200.

Chemical Flush

If you’re replacing an older boiler in your property then having a chemical flush to clean out your radiators may well be a necessary part of the installation. The chemical flush, as the name suggests, flushes out any unwanted sludge from the pipework and radiators this allows water to pass through unhindered. Having a chemical flush often improves the over efficiency of your home’s central heating system.

Prices Range from £80-£150.

In more severe cases it might be suggested to a power flush of your system. Power flushes work by forcing large amounts of pressure through the pipes and can cost in excess of £500 depending on the amount of labour involved in the job.

In the fourth part in this series we’re going to take a look at the average boiler installation with one of our trusted Gas Safe Engineers from All Heat UK. From start to finish what does a boiler installation look like and how often should you have your boiler serviced? We’ll find out in the next part.

Do you NEED to replace your boiler FAST? Then all you need to do is Visit Our Site then follow the link to ‘Get a Quote’ and before you know it, we’ll be at your door the next day, ready to install a brand new gas combi boiler to your home.

Who Can Install My Gas Combi Boiler?

New gas boilers of all kinds need to be installed by a Gas Safe registered Installer. The Gas Safe Register is the official governing body for the United Kingdom and Guernsey. Their Gas Safe Certificate ensures all work carried out on the property is done in a way that meets their safety and quality guidelines.

In the event that the boiler has been installed by someone who is not a Gas Safe Engineer, your boilers warranty would likely be voided and you could be held liable for any damage that is caused by a shoddy installation. Not only that but, an installation carried out by somebody who isn’t on the Gas Safe Register can lead to prosecution by your local council.

When it comes down to it you’re best to leave it to the professionals. If you’re unsure whether your engineer is Gas Safe or not then there are a few ways to check for yourself. Firstly, you can ask the your engineer, likely they will be able to give you their Licence number from their engineers ID card.

Secondly you can visit and either search for those numbers that have been provided by your engineer. If the engineer is on the register, then you’ll be able to see photos and details about the engineers qualifications. You can also check that the business you’re dealing with is on the Gas Safe Register by Texting the licence ID number to 85080, you’ll then receive a text back telling you if your engineer is legit or not.

Here at All Heat UK we offer next day boiler installation and replacement across the country! All you need to do is fill in our simple no obligation ‘boiler quote’ form and we’ll handle the rest.

We ONLY use Gas Safe Registered boiler installers plus we have a LARGE selection of boilers and brands to choose from!

What To Expect From A Gas Boiler Installation From All Heat UK

So now we’re going to take you through, step by step on an average gas combi boiler installation with All Heat UK to give you a greater idea of what to expect and how we can make the sometimes daunting task of having a boiler installation or replacement as easy as pie.

  1. Visit Our Site – Firstly visit our site Once you’re there you’ll be asked to fill out a few simple questions to help us get a picture of what sort of boiler you will need.
  2. Book Your installation – From there we’ll need to take a few more details and book the installation of your new combi boiler. We offer next day installation of all of our products, but we try to make your appointment as convenient as possible to our customers as we can.
  3. The Installation Day – On the day of your new combi boiler installation, your gas safe engineer will arrive promptly at the time they’d pre- arranged with you to begin to carry out the installation.
  4. During The Installation – Currently due to the Covid 19 restrictions you may well have to be in another room of your house entirely while the installation is carried out, don’t worry though that’s not too much different to what would normally happen. You may well hear a few bangs and bumps during the course of the installation, but it shouldn’t be anything too earth shattering. Once the installation is complete our engineers will then begin to clean up, our goal here would be to leave your property looking the same as when we first arrived, just a little bit warmer.
  5. After the Installation – After the installation is completed your boiler engineer will then take you through what changes have been made and how to use your new heating controls. They will then give you all your relevant warranty information (you’ll need to keep hold of those to validate your warranty) and then they’ll be on their way leaving you with the boiler of your dreams.

How Long Does It Take To Install A Gas Boiler?

The general answer here is anything from a few hours to a few days. The main contributing factors here are the amount and complexity of work that is entailed in completing the job.

In general Combi like for like replacement will take in the region of 4-6 hours (1 day of labour). This is the most common scenario we see here at All Heat UK’ . This time scale wouldn’t include processes like chemical or power flushes and if included your job could take longer to complete.

When it comes to processes like relocation your boiler or changing the type of boiler you have in your home is where you start to see install times reach in excess of 1 day of labour.

How Often Do I Need My Gas Boiler Serviced?

All gas and oil boilers should be serviced once per year to ensure that the unit is operating safely and efficiently. Most people opt to have their boiler service in the later summer to the earlier parts of autumn, this enables the engineer to fix any potential defects before the colder winter months arrive. Not only that, but having your boiler serviced at this time of year ensures you the peace of mind that you will make through those winter months without a breakdown. Having your boiler serviced before the winter can also have some other benefits, such as easier appointments and cheaper rates, this will largely depend on the gas safe engineer you choose and their pacific terms and conditions.

Gas boilers can only be serviced by a Gas Safe Engineer, while a separate governing body, OFTEC, takes care of the oil safety requirements.

If you’re a landlord it’s required by law that you have your gas boiler and flue annually checked in all the properties to rent to. And finally in many cases it’s required to have an annual service to keep the warranty on your boiler valid. As we discussed earlier in this article, many modern brands of boiler can come with staggeringly long warranties, so looking after them only makes sense.
Most boiler services last for at least 30 mins and usually wouldn’t last longer than 1hr, unless the engineer encounters some unforeseen circumstances.

Need your boiler serviced? The team at All Heat UK have many years experience and we’re here to help!

Visit Our Site for more information. (Terms and Conditions Apply)

In the final part of this article we’re going to take a look at the ‘5 Main Benefits From Having A New Gas Boiler Installed’.

5 Main Benefits Of Having A New Gas Combi Boiler Installed

Now, as we come to a close on this series of articles, we thought it would be an excellent way to round things off by highlighting some of the main benefits you can expect to receive once you’ve had your new combi boiler installed.

  1. Better Efficiency and Cheaper Bills – Once you have a new combi boiler installed in your home, you’ll soon find that your bills are getting cheaper. Cheaper bills are great but they’re just the side effect of having a boiler with better efficiency. We’ve seen some of our customers save as much as £300 on their yearly bill and that’s definitely not chump change. Bear in mind the amount of money you save in a year will differ depending on the size of your house and the age of your pre-existing boiler.
  2. More Accurate Controls – As we discussed earlier in this article all modern boilers these days pretty much have the capability to to be integrated with smart technology in one way or another. That smart integration means you have a greater control of your home’s heat, whether you’re at home or not.
  3. Prepared for Winter – Another one of the main benefits when it comes to boiler installation in general, is having the peace of mind that you have the best possible boiler you can possibly have before those winter months arrive. While you can have a boiler installation anytime of the year, it is again recommended that in the spring to summer months would be the best time for this to happen.
  4. Space Saving – Didn’t you always want a man cave, but you never had the space to do it before? Well, one of the main benefits when it comes to combi boiler installation is that it saves space. In some cases it could free up enough room for you to finally have that man cave you always dreamt of.
  5. Safer and More Reliable – Overall new gas combi boilers are far more safe and reliable than even a boiler from say 5 years ago. Not only that having a new boiler installation will mean you have a fresh warranty on your appliance, as we discussed earlier some combi boilers come with warranties that are in excess of 10 years. This means in the event of a breakdown happening, you’ll likely to pay nothing for the subsequent repair to fix the fault.

Which is The Cheapest Combi Boiler?

Many small boilers that you would consider to be in the ‘budget’ range would typically cost in the region of £450-£1000 and generally would have no less than 24kw output and no more than 42kw output, this is generally considered the minimum size boiler for small to medium sized homes with one bathroom and up to 10 radiators .

The Vokera Compact A DIN Combi 25kW Boiler – During our research the cheapest Combi boiler we could currently find is the A DIN 25kW by Vokera. This compact unit is able to fit inside of a kitchen cupboard. Vokera currently offers a 5 year warranty on this line of combi boiler plus it is really easy to install and maintain. The A DIN usually costs around £450 and although by a brand with no much market recognition, this by far is the cheapest boiler we could find.

As we highlighted earlier our favourite brand by a long shot is Worcester Bosch and when it comes to budget models, although a little more pricey the team over at Worcester Bosch have got you covered!

Our Picks For Cheapest Combi Boiler

Greenstar i Junior Combi or Greenstar Si Compact Combi – we’ve put these boilers up at first place because they’re both great and offer an excellent solution to those who want the quality that Worcester Bosch offers but on a budget that fits the smaller pocket.

The Greenstar I Junior Combi typically costs between £770.50-850.88 depending on who installs your boiler and what area you’re in. On the other hand the Greenstar Si Compact combi boiler is a little more expensive at prices starting around £850 but the team over at Worcester Bosch know how to put together quality boilers and we’d consider this money well spent.

If you want to know how much it’ll cost to have your boiler installation with one of our team here at All Heat UK then Click Here to visit our site for A FREE quote.

Which Is The Most Efficient Combi Boiler?

I’m afraid that we’re going to have to be quite predictable here with our first answer. It’s no secret that we love all of the boilers that are manufactured by Worcester Bosch but as far as energy efficiency goes this boiler stands head and shoulders above the rest.

Greenstar 2000 Combi 25kW

As far as energy efficiency goes you can’t go wrong with the Greenstar 2000. With an energy efficiency rating of A and a 5 year warranty it’s easy to see why this is a big favourite with customers and engineers alike. The Greenstar 2000 has a DB level of 43DB that means you won’t even notice that it’s there, it’s as quiet as a mouse, a little bigger.

Prices Online Around – £715.

Viessmann Vitodens 100–W (30kW) boiler

Another fantastic option for a ruthlessly efficient boiler is the Vitdens by Viessmann. The Vitodens is amongst the best affordable boilers and the excellent engineering involved in all their appliances ensures you know that you’ll end up with a very efficient boiler.

Prices Online Around – £1060.

Ideal Logic Combi C30

Our Final choice for the most efficient boiler is the Logic C30 by Ideal. This is another compact unit that can fit inside of a cupboard if needs be. An excellent choice for those who are trying to find the most energy efficient boiler solutions on the market.

Prices Online Around – £900

Conclusion: The Essential Guide to Gas Boiler Installation

In this series of articles we’ve discovered the ins and outs of choosing a combi boiler and combi boiler installation.

We’ve broken down the cost of boiler installation and what exactly to expect when you have your boiler installation with All Heat UK.

If you enjoyed reading this article, or if you were looking for Oil Boiler related content, you should read our Ultimate Guide to Oil Boiler Installation.