Copyright 2012 Pembrokeshire Gas Maintenance

Some of the properties in new developments have been built with boiler flues which cannot be inspected because they are hidden behind walls or ceilings. If you live in one of these homes, this document tells you what you need to do next.


Gas engineers need to be able to see the flue  which take fumes away from the boiler  as part of essential safety checks. A flue in poor condition, combined with a boiler that is not working  properly,  could  put  you  and  your  family  in  danger  from  carbon  monoxide  (CO) poisoning, which can cause death or serious injury.


If your boiler is situated on an outside wall, it’s unlikely you have this type of flue. Alternatively, if the engineer can see the entire flue, you will not need to take any further action in relation to this letter.


If you do have a boiler where all, or part of, the flue cannot be seen, you, or your landlord, will need to arrange for inspection hatches to be fitted. This does not mean, however, that your flue system is suddenly unsafe. As long as the boiler passes a series of safety checks  including having audible CO alarms fitted  it can be used normally for the time being.


CO alarms are not an alternative to being able to see the flue and you will still need to have inspection hatches fitted. You have until 31 December 2012 for this work to be completed. It is recommended, however, that inspection hatches are fitted as soon as you are able to do so. From

1 January 2013, any registered gas engineer will turn the boiler off, with your permission and formally advise you not to use it until inspection hatches have been fitted in appropriate places.


Although most of the affected boilers and flue systems are relatively new (installed since 2000), the risk of faults leading to the release of CO increases as the system gets older, especially if it is not serviced regularly.


You need to take action now.


If your property is less than two years old, contact your builder. If your property is between two and ten years old, contact your home warranty provider, as you may be covered by them if there are defects in the flue. However, the warranty providers listed overleaf have advised that cover is not provided for installing inspection hatches in homes over two years old. If your property is

10 years or older you should contact a Gas Safe registered engineer.


If you are a tenant, it is the responsibility of your landlord to ensure that inspection hatches are installed and that the boiler and flue are checked every year. You should pass a copy of this document on to your landlord.


Frequently Asked Questions


Why is carbon monoxide (CO) dangerous?

CO is a colourless, odourless, tasteless, poisonous gas produced by incomplete burning of carbonbased  fuels,  including  gas.  It  is  only  when  the  gas  does  not  burn  properly  that dangerous levels of CO are produced. CO stops the blood from bringing oxygen to cells, tissues, and organs and can kill quickly. Around 20 people in Great Britain die each year from CO poisoning caused by faulty gas appliances and flues.


CO poisoning can easily be confused with food poisoning, viral infections, flu or tiredness. Symptoms to look out for include headaches, breathlessness, nausea, dizziness, collapse, loss of consciousness, tiredness, drowsiness, vomiting, pains in the chest, stomach pains, erratic behaviour or visual problems.


What should I do if I think I am suffering from CO poisoning?


• Get fresh air immediately. Open doors and windows, turn off gas appliances and leave the house


• See your doctor immediately or go to hospital - let them know that you suspect carbon monoxide poisoning. They can do a blood or breath test to check


• If you think there is immediate danger, call the Gas Emergency Helpline on 0800 111 999


• Get a Gas Safe registered engineer to inspect your gas appliances and flues to see if there is a dangerous problem


If there is an immediate safety issue, why have I got until 31 December 2012 to fit inspection hatches?

Getting the work completed may take time, especially if you are contacting your builder or home warranty provider, or you may be waiting for your next scheduled boiler service. By getting your boiler serviced by a Gas Safe registered engineer and fitting audible CO alarm(s), to BS EN

50291:2001, you are helping to manage any risk until the inspection hatches have been installed.


Why are hidden flues an issue?


Advances in technology allowed boilers to be put in a greater variety of positions, not just on an outside wall, suiting the development of flats and apartments where space was at a premium. This resulted in some boilers being installed in a way that the flue cannot be inspected to make sure it is correctly fitted and safe.


Do I have to get inspection hatches by law?


No. There is no legal duty on the consumer to have inspection hatches installed. However, there is a long-standing legal duty on gas engineers to be able to visually check the flue to ensure it is safe. In the majority of cases this will be only be possible though the installation of inspection hatches. If gas engineers cannot view the flue along its length they will advise you from January 2013 that the installation is ‘At Risk’ and will seek your permission to turn it off.










Room-sealed fanned-draught chimney/flue systems concealed within voids. Consumer Information Pack and Risk Assessment Checklist