How an Engineer Commissions Your Gas Boiler

What is a boiler commission?

After a boiler is installed and connected, a boiler commissioning checklist is used by gas engineers to ensure the installation has been done correctly and safely.  The checklist ensures all the key checks are performed step by step and readings are recorded for future benchmarking.  The boiler is then safe to hand over to the customer.

As the manufacturer doesn’t usually install the boiler, building regulations require that boiler installations need to comply with the manufacturer’s instructions, and they provide a checklist for installers to follow and fill in when they have completed the relevant test.

The Boiler Benchmark Scheme

The Benchmark scheme aims to improve the standards of boiler installation in the UK and encourage the regular servicing of central heating systems so they are safe and efficient.

When it is filled in, the boiler benchmark commissioning checklist can be used to show compliance with Building Regulations and it is given to the customer to keep for future use: such as to help with the warranty, annual boiler servicing, home insurance and when selling the house etc.

Gas boiler commissioning checks

The following are the main checks a gas engineer will perform once the boiler has been installed:

• Check for gas leaks. Make sure the whole installation is ‘gas tight’.  By performing a tightness test at the meter, the engineer can check if there are any gas leaks in the system now the boiler has been fully installed.

• Is water heating up properly? After performing more checks at the meter, the engineer will then move to the boiler itself to check that the water is being heated up properly.  Depending on the output of the boiler, an amount of water will need to be heated up sufficiently in one minute.

• Check the right amount of gas is coming to the boiler. Next, the pressure coming into the boiler will be tested to see if it’s getting enough gas when it is turned on full.  If there is another gas appliance, such as a cooker, this will be turned on at the same time to see if that is affected at all.

• How much gas is the boiler using? The engineer will then move onto checking how much gas the boiler is using up when on maximum, the manufacturer’s instructions will state how much it should be per hour, known as gas rating and the boiler needs to comply with this figure.  Too high or too low on this figure will need to be investigated as this can affect safety and efficiency.  It could even be that the pipework needs to be increased so the boiler gets enough gas to function.

• Check the flame is igniting correctly. Then comes the safety check on the boiler to make sure that if for some reason there is no flame present to ignite the gas coming into it, the boiler shuts down to prevent gas build up which could cause an explosion.

• Is the boiler flue installed properly? The flue pipe coming out of the boiler will also be checked to make sure the boiler is getting rid of combustion fumes effectively and not going back into the room, this is done with a flue gas analyser.

• Fit a magnetic filter. During the commission, a magnetic filter will be added to collect metallic dust and debris from the radiators so they don’t go on to cause damage to the boiler.  Along with this, corrosion inhibitor will be put in to help maintain the system in good condition for longer.  It also helps delay repairs that could occur from the system being clogged.

• Record all the results. A ‘benchmark’ checklist is fully completed and signed to record the readings and confirm the boiler is safe to use. This is kept by the customer for future use by engineers who come to service and fix the boiler.

• Show the customer how to use the boiler safely. The engineer will then explain to the customer how the boiler works and sets the heating and hot water temperatures to the customer’s needs.

It’s all about Gas Safety

There are other checks done by the engineer when going through the checklist to make sure everything is recorded.  The engineer should explain some of the controls with the boiler and thermostat so you are informed and will register the boiler guarantee. They will also leave the manufacturer’s instructions with you.  Keep this in a safe place.

As you can see, there are many checks to be done to make sure the boiler is working properly and it is important you get someone competent and registered with Gas Safe to commission the boiler for you.