The Boiler Installation Guide

Technician repairing combi Gas Boiler

Buying a new boiler for your home can be quite the hassle. While preparation is key, you might feel like there are a hundred things that you need to do and prepare before you can get to the installation part of your new boiler. This installation guide will help in choosing which boiler to get and how to install the boiler based on its make and model. You also have to schedule when to get the boiler installed and whether you’re going to do the installation or not.

Picking the right boiler for your home is seemingly the easiest part of the buying process. But with over hundreds of boiler models and makes marketed on the Internet you’ll want to research and refine just what would be most appropriate for your needs. The consequences of buying an unreliable boiler would be disastrous; should your boiler suddenly stop working while you are trying to get hot water, then the malfunction will either slowly or instantly break your boiler.

Some people would even suggest making the selection of the boiler a secondary issue. The first issue should be whether to replace the old boiler that is currently installed on your property or to have it replaced instead. These things are not even discussed in most boiler installation guides.

This is why we’ve come up with this handy blog post to give both the new and old customers of boilers instructions on what are the best things to do and prepare in case of a new boiler installation.

Picking the Right Boiler for the Job

Before installing your boiler, you need to pick the right boiler for the job in hand. Take into consideration how much hot water you need for your home. For landlords/landladies, consider how many rooms you have that will require water. Bathrooms and kitchens are obvious choices and potentially if you expand the property perhaps size the potential additional rooms in too. There are various types of boiler that work in different ways.

Combi Boiler – As the name suggests, the combi boiler heats water coming from the cold pipes of your water system when it passes through the integral heat exchanger. Thus, the combi boiler heats the combined water before releasing the water for use. It’s usually just one wall-hung unit. Great for people who are looking for low maintenance costs and are saving space in their home.

Heat Only Boiler – Referred to as the regular or conventional boiler, the heat only boiler provides heating directly towards the radiator and works with a cylinder to provide your home with hot water. More common in older homes, the heat only boiler needs adequate space, such as the attic or basement.

System Boilers – System boilers work together with a hot water cylinder. The system is not open-vented and all components used by regular boilers to produce hot water are all integrated in the boiler itself. System boilers are often installed along with unvented hot water cylinders.

Replacing your Old Boiler?

Is it really cheaper to replace your old boiler than try to have it repaired? The question is much more complicated actually. Especially if you’re trying to save money by getting a cheaper boiler.

If that’s the case, the cheaper option might be to install the same type of boiler, as you’ll probably be able to use the same pipework, tank(s) and electric wiring. However, it might not be the best option. Especially if you’re planning on upgrading your shower system or you’re planning on renovating your home a few months from now.

In an old home, for example, the chances are you’d have a loft tank, a hot water storage tank and a boiler, but that’s probably because that was the only option when the house was built. Combi boilers only started making an appearance in the 1970s. If you have a small family with one bath, an electric shower and central heating, a combi boiler will almost certainly be sufficient.

If you currently have a combi boiler but you have a large family and multiple bathrooms that often get used simultaneously, the opposite is the case. You could find that a combi boiler, even one of the larger ones, might not be enough. It might be the right time to upgrade to a bigger boiler system with several cylinders and tanks.

If you recently moved to a new town, of course you can’t use your old boiler. You can either try to find the same exact make and model of the boiler that you were using in your old house if you liked how that worked. The make and model of the boiler will also depend on how big your new home is and if there’s enough space in the attic for new cylinders or tanks. If your new house comes with its own water heating system, then all of you have to decide is whether you can still use the current boiler or upgrade to a new one.

If you’re renting a new apartment, consider talking to your landlord for the new boiler installation. If your landlord/landlady already has a water heating system pre-installed in your unit, then you can decide whether you can use the present boiler or upgrade to a new one, depending on the charges your landlord/landlady will give you.

Certainly the older a boiler becomes the more inefficient it becomes over time. Coupled that in recent years boiler manufacturers have put more of a focus on being more energy efficient with more of an Eco-range which may not have been available before which effectively use less gas to heat the same size of property.

Boiler Installation Day

Contact your heating engineer for a quotation for the new boiler of your choice. The conversation should not be a quick 20 second talk about the installation of your boiler; rather, the engineer should carefully conduct a full heating survey of your house and learn everything about the heating and hot water requirements of your household.

When all of the information needed is collected, the heating engineer should give you what type and size of boiler you should get for your home. If your heating engineer has scoped the requirements correctly is that good, they’ll give you a good boiler for a good price range and one that will give you and your family the right amount of hot water that you’ll need on a daily or monthly basis.

Questions to Ask during Boiler Installation

Here are some of the best questions that you can ask your heating engineer during the pre-installation conversation:

  • Do you use a pumped water shower or have plans of installing them in the future? A combi boiler may sound like the best type of boiler for more residential houses, but it’s not a good type to choose for people who are using shower systems with a powerful electric pump. If you want to continue using the pumped water shower, then you’re going to have to choose a different boiler type.
  • Are you going to renovate your home soon? Informing your boiler installation team about your renovation plans in the future should help them decide where to put the boiler in an area where it will be least affected during the renovation.
  • How often do you use your hot water? – Do you regularly shower with hot water daily? Do any other members of your household want hot showers daily as well? These questions should be asked to determine the boiler that is right for your home.
  • What problems did you encounter with your boiler? – If you’re getting a new boiler to replace a broken one for your house, it might be worthwhile to talk to the installers about the issues you had with the old boiler. If you’re getting a new boiler for a new house, you can talk to the installers about any issues and recommendations that they can give for your new boiler.
  • Do you have hot water requirement changes within any time of the year? – Think of the holiday seasons. Are you going to have relatives visit you soon for Thanksgiving? You might want to consider these events and talk to the boiler installation team.
  • Do you have a particular brand of boiler that you use? – Brand reliability may come as an important aspect for you when choosing which boiler you want installed. Ask the installers if they have a brand that they are recommending based on your hot water usage and how many people are going to use the hot water.

Questions to Ask your Heating Engineer

Your heating engineer should be present with you while the boiler installation is commencing. You’ll get confidence that your heating engineer is good when they’ll ask you a series of questions about your boiler, how you want it installed, and how often you’ll use the boiler for hot water. If he doesn’t ask you about any of the questions presented below, you’ll want to ask them anyway so that he can advise the boiler installation team on how to proceed.

A good installer should also give you a full understanding regarding the questions below. While not all of the extra services mentioned will give your boiler the efficiency it needs, it’s part of their service to educate the owner too.

So without further ado, here are some of the best questions that you should be asking your heating engineer about:

  • Does my boiler have a condensate disposal? – The condensate disposal is the pipework that brings water produced from the boiler away from the drain. While this is important, the external pipework should be kept at minimum. For all external pipe installation, the installer should ensure that it is protected from freezing temperatures.
  • Does my boiler have scale reducers or system filters? – This is usually added as part of the quotation. If not, you can get these for around 110 pounds with installation. Scale reducers are very important for combi boilers installed in an area where hard water is present. While a power flush or system filter is not always necessary, you should make sure that the installers are setting up your boiler in a clean location to avoid future problems.
  • How big is the plume or vapour coming from the boiler? – Ask the heating engineer where the plume or water vapour coming from the boiler will appear outside your house. You also need to check if the plume is going to be a bother to your neighbors because of where the vent is situated.
  • Will radiators be included with my boiler? – Your installer may or may not recommend radiators installed on your boiler. It depends on the type of boiler that you’re going to use.
  • Will my boiler come with heating controls? – Your boiler may or may not come with heating controls. You can ask the boiler installation team for information on your boiler and any other option that you can add with it.
  • Does my boiler come with additional energy-saving features? – New government provisions require that each boiler installation should include one out of the four energy-saving features. You can choose from flue gas heat recovery, load-compensating thermostats, smart heating controls, or weather-compensating thermostats. You can discuss more about this with your heating engineer so you can decide which energy-saving feature works well for your current boiler.

Post Boiler Installation – What to Do and What to Check?

Once your boiler is installed, the boiler installation team should perform a series of performance and safety checks. This is a must and the results should be recorded on the back of your boiler’s instruction manual. This is usually a requirement for most installers as proof that the installation was a success and that they have followed installation procedures to the letter. Typically in the same cost the engineer will run a powerflush to ensure the system is clean throughout.

The installers should also register your boiler with the manufacturer to activate its warranty.

If you start using your heater and you notice a cold spot on the radiator or the radiator for your boiler is taking too long to heat up, then you might want to call your installers again so that they can troubleshoot your boiler. It could be a sign that your boiler needs cleaning or the heating system requires balancing.

Getting the right boiler installation team will certainly help in achieving a pain-free boiler installation, but we also believe that with your cooperation, the whole experience doesn’t need to be too much of a hassle.

Get the contact information from the installation team and your heating engineer. In case of emergencies, you should always have this information handy so you can be in touch with them as soon as possible. Inquire whether they have a separate hotline in case of emergencies or during late night breakdowns. It pays to get this and have them ready at hand instead of trying to look for those contact numbers when your boiler breaks down in the middle of the night!

The Boiler installation quotation – How Much Should you Expect?

Quotations can sometimes be confusing and nerve-wracking, especially if you’re set to buying multiple boilers for an apartment.

While your heating engineer can clearly sum up the quotation without problems, if considering that a typical boiler installation can cost between £2,000 and £3,000, then you’ll most likely want a complete and up-to-date computation for the quotation.

You can just imagine how much you’ll have to pay for when you’re getting multiple boilers for an apartment. Therefore it only makes sense that you want to get a quotation first before anything else. Of course, the quotation itself should be clear and up to date.

If you’re looking for a sample for an efficient installation quote, then these are some of the things that you should look for:

The price and model of the boiler installed – The quotation should come with a full explanation of why that boiler has been recommended, with reference to type and size. All extra heating controls should also be listed separately together with the cost.

The boiler location – An explanation of whether the boiler will remain in the same place as the previous boiler, or whether it needs to be moved. There should be a full explanation why the boiler needs to be moved sometime in the future.

Water treatment – Cleaning of the system is always required, but the quotation should also include what type of cleaning is needed for the boiler. There are 3 options: gravity flush, mains flush and power flush. Your installer should be able to advise you on the most appropriate method for your heating system.

A detailed overview of the labor costs.

The post-installation and system balancing checks – This shouldn’t necessarily incur any extra cost, but it should be mentioned by the engineer that they will make the necessary checks that your radiators are working and correctly balanced after the installation is complete.

A detailed explanation about your boiler’s warranty and what needs to be done to maintain the terms of the warranty, such as an annual service.

Boiler Plus

Back in 2017, new regulations were introduced to supervise boiler installations in the United Kingdom.

The Boiler Plus regulations requires all new gas boilers that are installed in the UK to follow these rules and regulations:

  • Gas boilers should have an ErP efficiency of at least 92%.
  • Combination boiler replacements must have an additional energy efficiency measure installed at the same time.
  • All gas and oil boilers installed need time and temperature controls installation. For boilers without any time and temperature controls, this needs to be rectified at once

Who does the Boiler Plus apply to?

Boiler Plus applies to all households in the UK. Adding an additional energy efficiency device may apply only to replacement combi boilers only.

For those who are planning on getting a new combi boiler, then you need to get any of the following energy-saving measure as part of the Boiler Plus provision:

Flue gas heat recovery – This system reduces heat from your boiler that would otherwise be wasted. FGHRS recover heat from waste flue gases to preheat the cold water entering the boiler, lowering the amount of energy needed to warm the water up to the required level. Almost all modern boilers already have some sort of heat recovery built in, making condensing boilers much more efficient than older ones.

Flue gas heat recovery systems can further increase the efficiency of these condensing boilers in most cases, delivering the same amount of heat with up to 4% less gas.

Load-compensating thermostat – The load-compensating thermostat adjusts the radiator temperature to be hotter when your home is cold. When your home is cooler, the thermostat adjusts your radiator temperature to be closer to the desired temperature.

These devices measure the gap between what the internal temperature is and what the user wants it to be and modulates the boiler so that it only uses as much fuel as necessary to close the gap. Load compensation is a common function in many smart controls and programmable thermostats, so might you want to check if this is already available for your boiler.

Weather-compensating thermostat – The weather compensating thermostat acts the same as a load compensating thermostat, but it adjusts the radiator temperature depending on the outside temperature.

Weather compensation interacts intelligently with the boiler to reduce water temperatures based on outside temperatures, which increases efficiency without compromising user comfort. This means that the boiler is better able to maintain a steady internal temperature by adjusting boiler output to account for changes in the weather. Weather compensators can be a simple external sensor feeding weather data back to the boiler.

Smart thermostat – The smart thermostat allows you to control your heating through a tablet or smartphone, whether you are inside or outside the home.

Automation is a function that allows the device to automatically control the heating system output in response to programmed demand (e.g. scheduling with temperature control) or occupancy detection.

Optimisation means the device calculates how long it takes the property to reach the desired comfort level, and times the system’s operation to minimise the amount of work it has to do.

Should you need to decide which of these energy-saving devices best fits your boiler, then you may want to talk to your heating engineer regarding this. Take note that some boilers may already have one of the Boiler Plus recommendations. One such example is the flue gas heat recovery, since most combi boilers may already have such a device.


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