DIY Boiler Installation: A Step by Step Guide

Published On: January 12, 20212 Comments on DIY Boiler Installation: A Step by Step GuideTags: , , Last Updated: February 9, 20244.3 min read

In this article, we are going to tell you how you can install a combi-boiler. Combi-boilers (combination boilers) are high-efficiency boilers that use gas for domestic water and central heating in a single unit. Combi-boilers are a great addition to any home and a wonderful space-saving idea. If you, like many in the world today, want to become efficient, then a combi-boiler could definitely be for you.

installed gas boiler

They are simply installed, bother free, and a great addition to any home, regardless of size or location. We hope that by the end of this article that you will know exactly how to install a combi-boiler.

What is a Combi-Boiler?

Combi-boilers, as explained in the previous paragraph, are a type of boiler that is used to heat domestic water and heat your central heating system. Combi-boilers combine, as the name suggests, these two functions, therefore improving your home’s efficiency massively and meaning you do not need a huge, tanked boiler, or two separate tanks as many homes do. They are very economical to operate and are a great addition to any home. If you’re looking to install a combi boiler yourself, you should definitely check out reviews and compare units to make sure you have the best combi boiler for your home. Like every boiler, they need to be serviced now and again. You should always ensure, on a side note, that you have your boiler serviced yearly so that it does not fall into disrepair and break down on you (nobody wants that!).

Can You Install a Boiler Yourself?

Can you install a boiler yourself you ask? Well, if you couldn’t this page wouldn’t exist, would it? It’s fair to say that water heater installs are not easy and can be a bit of a challenge, but like everything else, with perseverance, you can learn to install them. Installations on boilers can be very costly, so by opting to install it yourself, you save yourself the money of having to pay a contractor to be dispatched to your home and install the boiler for you. Installing it yourself also gives you technical knowledge so that should you need to do it again in the future, you will be able to. It is our opinion that the best way to install a boiler is to do it yourself. Why pay somebody to do something that you can do yourself? Yes, paying somebody may save you time, but it certainly won’t save you money. What’s more important to you? Some say time is money…


So, you have decided to install your boiler yourself. You should know from the start, it is no easy feat, and you must give it serious thought beforehand. Here’re a few of the steps you can expect:

  • Firstly, you must read the instruction manual in its entirety; if there is anything unclear from the instruction manual, we recommend that you phone up and ask for help from the manufacturer;
  • You should study the diagrams with each instruction. The diagrams can sometimes be more informative than the text that accompanies them;
  • You should lay out all of the tools and materials necessary for each individual stage;
  • You should ensure you have every single component necessary to complete the installation, lest you stop halfway through.

Where Does It Go?

When you have everything ready, you should find out where your boiler goes; you must know where it goes in relation to radiators and pipes. If you are installing a new radiator, too, then you will want to know where that goes, too. You should ensure that around the site where the boiler will go that you have plenty of space – you will also need to ensure you have the appropriate sealant and adhesive to seal up your walls afterwards.

pipes and heat pump


The location of pipes is very important, you must know the routes of the pipes in your home, otherwise, you could have a big problem. By knowing the routes of the pipes, you ensure the boiler can be installed easily and quickly.

Fitting Your Boiler

Fitting your boiler can be very difficult as we have explained throughout this article. Providing you have read the manual, however, you should be okay. You must exercise caution when you are installing your boiler. Follow the instruction guide to the very letter to ensure everything is done right. Make sure you turn off all of the electrics in your home and the water pipes before undertaking your boiler fitting – as if you do not you can cause a lot of trouble and potentially harm yourself (which we are sure you do not want to do). Good luck! As this article has demonstrated, installing a boiler, while difficult, can be done. We hope that you have found this article informative and instructional and has given you the confidence to install your own boiler and save yourself a ton of money. We hope you return and join us soon!

Share This Tip With Your Friends!

About the Author: Handyman tips team

The Handyman Tips Team is a group of authors that provides tips on the Handyman Tips website. The Handyman Tips team consists of real handymen, contractors, carpenters, woodworkers, and experts in home repairs, appliance repairs, and landscaping. The team is always there for visitors to the Handyman Tips website. If you can't find the answer to your question on the Handyman Tips website, one of them will reply to you almost immediately if you contact them through the Ask the Handyman page!

Leave A Comment

  1. Jasson June 18, 2022 at 1:42 pm

    very useful blog . thank you for sharing .

  2. Leo January 23, 2022 at 8:28 pm

    Pretty sure you need to be trained as a gas engineer to install a gas combi boiler.
    I am not saying that you cannot do it by yourself, by all means you can, but at the end of the install you definitely need to commission the boiler and for that you need to know exactly what to do and have a flue gas analyser which can get to way over 1000£ and you need to know how to work it.
    There are other steps to be considered while installing it, gas pressure, gas leaks, not to talk about water leaks and the most important…what do you do if the boiler goes into lock mode?
    You need to get a trained person, if he sees that it’s DIY, it will cap off the gas supply, contact a few organisations and you can get another hefty bill to redo all the check and try to get the boiler running, setting aside the fact that you will have to answer quite a few phone calls, no future warranty and have quite a couple of issues in the future because one of the main rules in working with gas is to “protect life and property” (Gas Legislation) and for that you may be charged.
    It can be done, not saying that it cannot, but there are quite a few implications and if the slightness thing goes wrong, a lot of things will go wrong.

Related Posts