• The Gas Supply

    The gas supply feeding our boilers in the home, especially the combination boiler is very important if we want the boiler to work to its full potential.

    As a gas safe registered installer,

    I have come across many boilers not working as they were designed to,

    IE, only working at half there design value.

    The main reason for this is the gas supply,

    but when you try to explain this to the customer or gas user they say, it seems to be working fine.

    One of the first questions I always ask the user is if they have a combination boiler is, the hot water, is it hot enough for you.

    The answer is normally yes it’s ok or something like my friend has the same boiler and the hot water is a lot better than mine, or it seems to run a lot faster.

    The gas supply to the boiler is very important,

    in that, it needs to be of the correct size.

    In the past, I have seen a 28KW combination boiler with the gas supply being feed in 15m pipes.

    On talking to the gas user, I asked does the boiler give any problems?

    The answer, no it’s fine, what about the hot water? Answer it’s a little slow but it’s ok.

    I explained to the user that the gas supply pipework was too small for this

    boiler and that it should be a minimum of 22m in size to within one meter of the boiler.

    On carrying out a boiler service,

    I checked the gas pressure at the boiler, this was giving me a reading of 22mb,

    but as soon as I switched the hot water on this dropped to 11.5 MB, 

    which under gas safety regulations is a shutdown.

    On further checking, I traced the gas supply pipework back to the gas meter.

    Whoever had installed the boiler had run the gas supply from the boiler to the gas meter in 15m-pipework.

    I then wanted to check the hot water flow rate just to see what the water was like.

    To get the water hot enough to wash with, I was only getting 5.5 litres

    This boiler should have been giving 12 litres.

    I explained to the user, that the boiler had failed the safety checks, due to the incorrect gas supply, and that I needed to make it safe.

    As you can imagine they were not happy.

    To run a new gas supply of the correct size was an easy job,

    so I worked out a cost and told the user that if they wanted the boiler

    back up and running that this is how much it would cost.

    I even said that if they did not see an improvement in the flow rate of the hot water,

    then I would drop my costs and the job would be free.

    They then agreed on the work to be done.

    The gas supply was installed from the boiler right back to the meter, the pipe size was 22m,

    A gas tightness test was carried out, all fine

    Next, checked the gas supply at the boiler 22mb, checked again with hot water on full flow 19.4mb.

    Once the user was shown the difference in the water flow rate and the boiler would now work how it was designed to,

    they were very happy to pay my costs.

    I was later told that a friend had installed the boiler for them and also had run a new gas supply, I asked was gas safe registered, no was the answer.

    This is why it’s so important to use a gas safe registered company or engineer to work on your boiler or any gas appliance.

    They will calculate the right size gas supply for your appliances.

    The gas safe engineer is not just an everyday plumber, he is a highly trained person, who every 5 years has to return to college to re-sit his qualifications, who is also checked regularly by gas safe.

    Everybody has a friend or family member who can do any handy jobs for a small fee,

    but a gas supply is very important, and should only be installed by a gas safe registered engineer. If done wrong it could cost lives.

    There are many boilers out there with the wrong size gas supply, is yours one of them?

    Then why not give your local gas safe registered engineer a call and ask him to come and check you have the correct gas supply…