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Kidde Firex KF10 Ionisation Smoke Detector and Alarm with 9V Battery Backup - Replaces Firex 4870, I240C, I230C,

  • Retrofit for the Kidde Firex 4870 I240C / I230C 

  • 230V Hard Wired Mains Ionisation Smoke Detector with Battery Back Up 

  • Interconnects to 23 Other Alarms

  • Combined Test & Hush Button 

  • Guaranteed for 6 Years 

Availability: In stock

Regular Price: £16.26

Special Price Excl. VAT: £9.90 Incl. VAT: £11.88

Product Description


There are two types of smoke alarm currently on the market - ionisation and optical (also described as photo electronic)

Ionisation: These are the cheapest and cost very little to purchase. They are very sensitive to small particles of smoke produced by flaming fires, such as chip pans and will detect this type of fire before the smoke gets too thick. They are marginally less sensitive to slow burning and smouldering fires which give off larger quantities of smoke before flaming occurs.

Optical: These are more expensive but more effective at detecting larger particles of smoke produced by slow-burning fires, such as smouldering foam-filled upholstery and overheated PVC wiring. They are marginally less sensitive to free burning flaming fires.

Each type looks similar and is powered either by a battery or mains electricity (or a combination of both). Some are inter-connectable so that any smoke detected at one point can raise the alarm at all others.

In a standard smoke alarm, the battery will need to be replaced every 12 months. You can buy alarms fitted with 10 and 15 year batteries. The advantage is that you don't have to replace the battery every year.

Mains-powered alarms eliminate the problem of checking the battery. But to be really safe you need a battery back-up (which costs extra). They need to be installed by a qualified electrician.

Some people find their alarms are frequently set off when they're cooking or when the toast burns. This is partly a problem of positioning (the alarm shouldn't be in the kitchen or right outside it). But it can be made less annoying by a button that quietens the alarm temporarily.

The alarm lets you know it's been silenced by "chirping" or by displaying a red light - and a real fire producing lots of smoke will set it off anyway.

When deciding which type of alarm to buy you should consider which type of fire is most likely to occur in your home. Generally, both types of fire are common so the best form of protection would be to choose at least one smoke alarm of each type. Ideally, and to ensure continuity of supply, mains powered alarms with a back up power supply (e.g. battery, rechargeable capacitor) are the best option but simple battery powered alarms of either type will give good minimum protection.

The number of smoke alarms to fit in your home depends on your particular circumstances. Fires can start anywhere, so the more that are fitted, the higher the level of protection.

For maximum protection an alarm should be fitted in every room (except kitchen, bathroom and garage). You should choose the type most suited to the risk in each room. For minimum protection the number to be fitted will depend on the type of home you live in.

The 4870 is an ionisation sensor type of smoke detector. Up to 36 additional Firex Detectors can be linked to it for a total alarm system for complete piece of mind.

Smoke alarms need very little maintenance. A few minutes of your time during the year will ensure that your alarm is working and could help save your life and the lives of your family.

You should:
Once a week test each alarm by pressing the test button till the alarm sounds.
Once a year change the battery (unless it's a ten-year alarm).
Twice a year open the case and gently vacuum the inside using the soft-brush attachment to remove dust from the sensors. If it doesn't open, vacuum through the holes.
After 10 years it's best to get a whole new alarm.

Buying and fitting smoke alarms and ensuring they are carefully and properly maintained, could give you those precious few extra minutes in which to make your escape safely.

Plan an escape from your home in advance and talk about it with your family. If a fire occurs you may have to get out in the dark and difficult conditions. Escaping will be a lot easier if everyone knows where to go. Make sure your routes remain free of any obstructions and that there are no loose floor coverings that could trip you.

Always check the battery regularly, replacing it when necessary and never remove it for other purposes.

Cooking appliances are the source of most residential fires, but due to steam
and cooking particles, the kitchen is a location, unsuitable for smoke alarms.

The Building Regulations Heat Alarm requirement, applies in England & Wales, N. Ireland & Eire,
but has not neen adopted in Scotland.

Other areas to consider are Garages where exhaust fumes may damage smoke alarms,but where a considerable amount of flammable material may be stored eg petrol/paraffin/turps/barbecue
fuels/paint/cardboard etc.

Many integral garages are often sited under bedrooms.

Unconverted loft spaces are another area: converted ones should have smoke alarms.

The dust and many temperature changes in a loft space make smoke alarms
unsuitable in this location.

• No single type of alarm is suitable for the whole house

Kidde strongly recommends that both ionisation and photoelectric smoke alarms be installed to help ensure maximum detection of the various types of fires that can occur within the home.

Heat alarms are useful in areas with condensation/dust/high humidity, such as kitchens and lofts.

Heat alarms MUST ALWAYS be interconnected to smoke alarms.

Kidde recommends smoke alarms shall be installed outside each separate sleeping area in the immediate vicinity of the bedrooms and on each additional story of the family home, including basement and excluding unfinished attics; these should be protected by Heat Alarms.

In new construction, we recommend a smoke alarm also should be installed in all bedrooms/sleeping areas. supply Smoke Alarms, Heat & CO Alarms for Social Housing Providers, F M Managers, Electrical Installers, Fire Services, House Builders, Electricians and for DIY installers.

Additional Information

Additional Information

Dimensions No


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