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What Happens During A Boiler Installation?

What Happens During A Boiler Installation

Installing a new boiler can be an expensive investment and it’s crucial that you have it installed correctly by a qualified heating engineer. At NJ Harkus, we install hundreds of boilers each year across Cardiff and our boiler installation in Cardiff is by far the most popular service we offer.

To give you an idea of what’s involved during our boiler installation process, we’ve written the below guide that looks at the steps involved in a typical boiler installation.

Step By Step Guide To Installing A Boiler

1. Removal of The Old Boiler

The first step is to remove the old boiler. This may involve disconnecting pipes, electrical wiring and removing any flue or chimney systems that were used with the old boiler.

Once the old boiler has been disconnected, it can then be removed from the property and disposed of in an environmentally safe manner.

It’s worth pointing out that if you want to save a bit of money, you may be able to take your old boiler to an authorised scrap dealer as it can be worth a sizeable amount in scrap.

2. Powerflush The Central Heating System

Once the old boiler has been removed, the heating system can then be flushed and cleaned to remove any debris and sludge that may have accumulated in the pipes. The flushing of the system ensures that the new boiler operates more efficiently and it’s highly recommended.

3. Pipework Changes & Upgrades

Although not always necessary, you may need to install new pipes or upgrade existing pipes to better accommodate the new boiler. This step is important as it will help ensure that the new boiler operates efficiently and provides heat to all parts of the building.

4. Fit The New Boiler

Once the pipework has been upgraded, the new boiler can now be fitted. This’ll involve connecting the pipes, electrical wiring and installing any flue or chimney systems that are required. The heating engineer will make sure that the new boiler is securely and safely installed and that all the connections are tight and secure.

5. Install Additional Accessories

After the new boiler is installed, you may want to fit any necessary accessories, such as a programmer, smart thermostat or magnetic filter. These accessories will help ensure that the new boiler operates efficiently and provides heat to the building when it’s needed.

6. Commissioning of The System

Once the new boiler and accessories have been installed, the heating engineer will commission the system. This involves testing all the components of the new heating system to make sure that everything is working correctly and that the new boiler is providing heat to the building as it should.

7. Handover & Certificates

Once the new heating system has been commissioned, the heating engineer will hand over the system to the property owner. This will include providing certificates to show that the new boiler has been installed correctly and is safe to use.

8. Registration

Finally, the new boiler needs to be registered with the boiler’s manufacturer. This is crucial because if anything were to go wrong with the boiler within the warranty period, it’ll be replaced free of charge by the manufacturer.


At NJ Harkus, the majority of our reviews come from installing boilers throughout Cardiff and the surrounding areas. Therefore, we have plenty of experience and although the above steps cover the “typical” system, all boiler installations differ. If you require further information regarding the steps involved to install a boiler, feel free to get in touch.

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