Isle of Wight Council

Housing Enforcement

Carbon monoxide

If you think you may have a carbon monoxide (CO) problem, follow the basic do’s and don’ts below:



If you are a tenant, contact your landlord/ letting agent immediately to advise on your concerns Use a gas oven to heat your home
If you are an owner occupier, engage with a relevant heating engineer to inspect your appliances Use fuel burning appliances within the home, until they have been checked by a competent person and you have a CO detector installed
Buy and install a CO detector (or if you are a tenant, contact your landlord/agent to) Use a solid fuel burning appliance in any room without a working CO detector in the same room
Pay attention to symptoms such as headaches, dizziness, nausea, shortness of breath or stomach pain (especially if more than one person is affected) and seek medical advice Use fuel burning tools within the home
Cook with a BBQ or grill within the home, even in a fireplace
Sleep in a room with unvented gas or kerosene heaters
Leave a vehicle running in an enclosed space. For example, a garage
  Use oversized pots on your oven, or place foil around the burners
  Block air vents


The Smoke Alarm and Carbon Monoxide Alarm Regulations (England) require certain types of rented accommodation to be provided with smoke detectors and, if necessary, CO detectors. 

Basic facts

CO is termed “The Silent Killer” as it has no smell, taste or colour, and it can kill without warning in a matter of hours. Every year about 30 people die, whilst many others also suffer ill health, from CO poisoning. This is caused by any fossil fuel burning appliance, for example, gas, coal, diesel, oil or wood, and the associated flues and chimneys that have not been properly installed or maintained.  When a fossil fuel does not burn properly, excess CO is produced.


CO can leak from flues, cooking and heating appliances. This can be because they have been poorly maintained or break down. Poor ventilation or blocked flues are frequently to blame. Even severe weather conditions can cause leaks that can prove fatal. Leaks can be caused by many sources and are not always related to an appliance malfunction.

Modern housing insulations can make a problem worse by creating an airtight environment. For example, double glazing.

Affects and symptoms of CO exposure

Blood contains a substance called haemoglobin which is used to carry oxygen around the body. Haemoglobin also carries CO, in preference to oxygen.  When you breathe in air containing CO, it replaces the oxygen, and you suffocate from the inside, causing death.

The symptoms of CO exposure include:

  • Tiredness
  • Drowsiness
  • Headaches
  • Giddiness
  • Nausea
  • Vomiting
  • Chest pain
  • Breathlessness
  • Stomach pain
  • Erratic behaviour
  • Visual problems

These symptoms can easily be confused as flu, or tiredness. It can kill quickly when it leaks in large quantities or can build up over time.

If you or your family experience the above symptoms and you believe CO may be involved, you must seek urgent medical advice. Your doctor will need to test you for a blood or breath sample.

Risk indicators

You could be at risk of CO problems if:

  • your appliance was poorly installed
  • your appliance is not working properly
  • your appliance has not been checked for safety or maintained regularly
  • there is not enough fresh air in the room
  • your chimney or flue gets blocked up
  • you allow non-Gas Safe registered engineers to install or maintain your gas burning appliance(s)

How to detect a problem

There are several early warning signs to look for if you are suffering from CO problems. They include:

  • yellow or brown staining around, or on appliances
  • pilot lights that frequently blow out
  • increased condensation inside windows
  • yellow rather than blue flame, apart from flue less fires

You can also detect problem by using an electronic detector (similar in appearance to a smoke detector) and also patch detector (changes colour if exposed to excess CO).

If your alarm goes off, or you notice that your detector patch has discoloured you should:

  • Open doors and windows in the room containing the appliance
  • Turn off/put out the fuel burning appliance 
  • Leave the area with the appliance off/out 
  • Seek immediate medical advice for any persons who could be suffering from exposure to CO 
  • Contact your fuel provider and explain the issue 
  • Contact an expert. For example, a Gas Safe registered contractor. If you are a tenant contact your letting agent or landlord 
  • Do not re-enter the affected area until the alarm has ceased to sound 
  • Carry out all required works to the appliance before using it again

Flues in ceiling spaces

If you 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. CO alarms are not an alternative.

If you do not have inspection hatches fitted any Gas Safe Registered engineer will turn the boiler off. They will tell you not to use it until hatches have been fitted.

For further information please visit Gas Safe Register.

Outside of the home

CO issues do not just affect the home. Awareness is important in several recreational situations. For example, camping and sailing.

Always consider what CO equipment you are using and take steps to minimise any risks.

Specialist advice

When installing or maintaining all types of CO detectors and alarms you should follow the manufacturers guidance.

For further specialised advice visit: