Are you all set to get a new boiler, but wonder what an engineer should do once he actually gets there?
Boiler installations are a mystery to most typical home owners. So, how do you tell if an engineer is doing everything they’re supposed to when commissioning your boiler?
Perhaps you’ve been researching online, or have had a few quotes only to be told some conflicting information. It can be confusing if you don’t know what to believe.
Well, there are quite a few steps to fitting a new boiler. As an experienced engineer, I’m going to talk you through 7 things an engineer does (or should do) when commissioning yours. So, you can know what to expect when they’re fitting one in your home!
NOTE: This blog covers a typical boiler installation, and doesn’t take into account the type of boiler you have, or whether or not you’ve chosen to have a magnetic central heating filter installed – which we highly recommend, by the way.
1. Cleanse the system
It’s very important that your central heating system is cleansed as per manufacturer’s instructions. It should also be flushed 2 – 3 times. This means the black magnetite is not going through the heat exchanger of the new boiler (that’s a good thing).
2. Add a good corrosion inhibitor
After the system has been cleansed, a corrosion inhibitor must be added. This will protect your boiler and radiators and stops hydrogen gas within the system, making it quicker. All manufacturers recommend this, as it helps to prevent corrosion.
3. Gas flue analyser test
It’s mandatory that the benchmark book is filled in and the analyser readings are written in. Although all boilers come factory set, there are occasions when the readings are too high or too low. I’ve noticed if the readings on Worcester Bosch boilers are too low on low-fire, the boiler can whistle when the gas valve is open.
4. Gas rate the boiler
Another technical one. Your engineer may have connected the boiler to an existing pipe which looks the correct diameter. However, if during gas rating, the readings are not correct, the pipe may be blocked or not sized correctly below the floor.
5. Set the boiler output
This is also important, as the boiler output must be set to the size of your house and number of radiators. For instance, the Worcester Bosch Classic models have a heat output of 30kW to your radiators, whereas the compact models have a 24kW output to your radiators.
You may only have 5 or 6 radiators and only require 18kW to the heating, so your boiler should be adjusted for this.
6. Register your guarantee/s
It’s best your engineer does this, as most manufacturers ask for technical information. They will usually also have an installer app to do this.
If you have a Worcester Bosch or similar deal where your controls and filter are guaranteed as part of the same package, they will also register these for you at the same time.
7. Gas tightness test
Your engineer will have to conduct a tightness test before your boiler can be commissioned. This is to check the gas pipe that runs from the meter to the boiler is holding pressure. As long as there is no dropping pressure, there should be no leaks.
8. Let by
The let by test involves connecting a gas test gauge to the gas meter, opening the supply valve and observing the gas test gauge. If the gauge is going up when you’ve turned the handle off, it means gas is still coming through – which is bad. This means the supply valve is ‘letting by’, and should be repaired immediately.
9. Explain how everything works
Finally, after commissioning your boiler, your engineer should explain to you how the boiler and controls work. They’ll also go over the boiler warranty, installer warranty and necessary servicing with you.
This is so you know what is covered, and who to call if there’s an issue. You’ll also want to know the best, most efficient way to run your new boiler.
Advice from an experienced engineer
The best advice I can give you is to read these blogs, get as much advice as possible, and don’t be afraid to ask the installer about the things mentioned above. It’s all standard procedure. If an engineer says they don’t do any of the above, stay safe and choose another installer.
The biggest thing I get asked about is flushing and cleansing. There are a lot of different opinions about it. Lesser engineers tend to say it’s not necessary, but it does make a difference. From experience, if a system is flushed and cleansed, we don’t get called back. There’s no problems.
Also, fitting a magnetic central heating filter is a must. So, if it’s missing from your quote, check you’re definitely going to get one.
Conclusion
I hope this blog has helped shed some light on the steps an engineer goes through when commissioning your boiler. As you can see, it can get quite technical, but it’s wise to check they will definitely take the time to go through these procedures.
Finally, don’t forget to ask about whether or not they’ll add corrosion inhibitor, and fit a magnetic central heating filter!
Do you have any other questions about what happens when commissioning your boiler? Let me know in the comments. I’d love to hear from you!
