The heating’s back on, the windows are shut and the log burner is lit for the first time since spring. It’s the time of year when carbon monoxide matters most. Fit a carbon monoxide alarm in every room with a fuel-burning appliance, such as a boiler, gas fire or wood burner, test it monthly and replace it before its expiry date. Alongside an annual boiler service, that’s the simplest way to protect your household in the New Forest this winter.
Why carbon monoxide is so dangerous
Carbon monoxide (CO) is a poisonous gas you can’t see, smell or taste. It’s produced when fuels like gas, oil, coal and wood don’t burn properly. A faulty or poorly maintained boiler, a blocked flue or chimney, or poor ventilation can all cause it. Only an alarm will warn you that it’s there.
Where to fit a carbon monoxide alarm
Always follow the manufacturer’s instructions that come with your alarm. Commonly recommended positions are:
- In every room with a fuel-burning appliance, such as a boiler, gas fire, open fire or wood burner
- Between 1 and 3 metres horizontally from the appliance
- On the ceiling, at least 300mm from any wall, or on a wall, higher than any door or window but at least 150mm below the ceiling
- In bedrooms and main living areas, as extra protection, at around head height when lying or sitting
Avoid fitting alarms:
- Directly above a cooker, sink or boiler
- In enclosed cupboards or behind curtains or furniture
- Next to extractor fans, vents or open windows
- In very damp areas such as bathrooms
How to test your alarm
- Press the test button once a month. It should sound a loud alarm.
- Check the expiry date. Many CO alarms last several years, but the exact lifespan is printed on the alarm or in the instructions.
- Listen for end-of-life chirps or warning signals, and replace the alarm if you hear them.
- Choose an alarm that meets BS EN 50291, which is the standard for domestic CO alarms.
Testing the button checks the alarm’s electronics and sounder. It doesn’t prove the sensor works, which is why replacing alarms at the end of their life matters.
Warning signs of carbon monoxide poisoning
Early symptoms are easy to mistake for flu or tiredness:
- Headaches
- Dizziness
- Nausea
- Tiredness and confusion
- Breathlessness
Be suspicious if symptoms ease when you leave the house, if several people (or pets) feel unwell at once, or if they’re worse when the heating is on. Look out for yellow or orange flames on gas appliances, soot or staining around appliances, and more condensation than usual.
What to do if your alarm goes off
- Open doors and windows
- Turn off fuel-burning appliances if it’s safe to do so
- Get everyone out of the property
- Call the National Gas Emergency Service on 0800 111 999 if you have gas appliances
- Seek medical advice if anyone feels unwell
- Don’t use the appliance again until a Gas Safe registered engineer (or OFTEC registered technician for oil) has checked it
Wood burners and older homes around the New Forest
Wood burners and open fires are popular in cottages and older homes around Ringwood, Lymington and the forest villages. They’re a source of carbon monoxide too, so the room they’re in needs an alarm, and chimneys should be swept regularly. If your boiler or heating is older, our heating page explains the work we do to keep systems running safely.
Frequently asked questions
Do I need a carbon monoxide alarm if I have a combi boiler?
Yes. Any boiler that burns gas or oil can produce carbon monoxide if something goes wrong, however new it is. A CO alarm in the room where the boiler is fitted, or just outside the cupboard it sits in, gives you an early warning if a fault develops between services.
Can a smoke alarm detect carbon monoxide?
No. Smoke alarms detect smoke from fires, not carbon monoxide. You need a separate CO alarm, or a combined smoke and CO alarm that’s designed to detect both. Check the packaging carefully and make sure any CO alarm meets the relevant British Standard.
How long do carbon monoxide alarms last?
It depends on the model. Many have a sealed battery and sensor that last several years, and the expiry date is usually printed on the alarm. Once it’s reached, replace the whole alarm. A loud chirp or flashing light often signals the end of its life.
Do landlords have to fit carbon monoxide alarms?
In England, landlords must fit a CO alarm in any room used as living accommodation that has a fixed combustion appliance, excluding gas cookers, and repair or replace alarms once told they’re faulty. Landlords should check the current government guidance for the full requirements.
Want your boiler checked this winter?
If your CO alarm has gone off, or you’d just like your boiler checked over before winter, give us a call on 01425 542077 or drop us a message and we’ll book a Gas Safe engineer to come out.