As one of the most popular 230v smoke alarms in the UK, the Firex KF20 from Kidde is a smart choice. Replacing the now discontinued Kidde 4973, this smoke alarm can be interconnected with as many as 23 compatible devices. The unit is easy to install, and screws and wall plugs are included. Conforms to BS 5839 pt6 Grade D, and also CE marked. Features a hush button for quieting false or nuisance alarms, and also a battery test button to ensure battery life is adequate. Optical alarms, also known as photoelectric detect smouldering types of fires, and should be used in living areas such as hallways, stairway landings and bedrooms. Do not use this or any other optical smoke alarm near kitchens or shower rooms. Measurements are 127mm in diameter, and 39mm deep. Manufactured by Kidde Firex.
As one of the most popular 230v smoke alarms in the UK, the Firex KF20 from Kidde is a smart choice. Replacing the now discontinued Kidde 4973, this smoke alarm can be interconnected with as many as 23 compatible devices. The unit is easy to install, and screws and wall plugs are included. Conforms to BS 5839 pt6 Grade D, and also CE marked. Features a hush button for quieting false or nuisance alarms, and also a battery test button to ensure battery life is adequate. Optical alarms, also known as photoelectric detect smouldering types of fires, and should be used in living areas such as hallways, stairway landings and bedrooms. Do not use this or any other optical smoke alarm near kitchens or shower rooms. Measurements are 127mm in diameter, and 39mm deep. Manufactured by Kidde Firex.
As one of the most popular 230v smoke alarms in the UK, the Firex KF20 from Kidde is a smart choice. Replacing the now discontinued Kidde 4973, this smoke alarm can be interconnected with as many as 23 compatible devices. The unit is easy to install, and screws and wall plugs are included. Conforms to BS 5839 pt6 Grade D, and also CE marked. Features a hush button for quieting false or nuisance alarms, and also a battery test button to ensure battery life is adequate. Optical alarms, also known as photoelectric detect smouldering types of fires, and should be used in living areas such as hallways, stairway landings and bedrooms. Do not use this or any other optical smoke alarm near kitchens or shower rooms. Measurements are 127mm in diameter, and 39mm deep. Manufactured by Kidde Firex.
As one of the most popular 230v smoke alarms in the UK, the Firex KF20 from Kidde is a smart choice. Replacing the now discontinued Kidde 4973, this smoke alarm can be interconnected with as many as 23 compatible devices. The unit is easy to install, and screws and wall plugs are included. Conforms to BS 5839 pt6 Grade D, and also CE marked. Features a hush button for quieting false or nuisance alarms, and also a battery test button to ensure battery life is adequate. Optical alarms, also known as photoelectric detect smouldering types of fires, and should be used in living areas such as hallways, stairway landings and bedrooms. Do not use this or any other optical smoke alarm near kitchens or shower rooms. Measurements are 127mm in diameter, and 39mm deep. Manufactured by Kidde Firex.
Last updated at 03/21/2026 18:26:06
KF20 Optical Smoke Alarm
Free delivery between 31 Mar – 3 Apr
KF20 Optical Smoke Alarm
Free delivery between 30 Mar – 2 Apr
Kidde Kf20 Mains-powered Interconnectable Optical Smoke Alarm 230v
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
originally posted on Safelincs - Fire Safety Products
Replaced old alarms which are discontinued as described.This alarm was shown as the best replacement for one that had been discontinued & was similar in fitting & function. So far its living up to what was advertised. Very pleased
originally posted on Builder Depot
Well built alarm. I've switched to optical alarms as we've had issues with ionization alarms false-triggering - usually at three in the morning. Too early to tell for this one, but happy with product in general
originally posted on superlecdirect.com
I tried to used the same screw hold as the old one but a slight modification in the ceiling was required for the plug to fit inside the base plate I.e. A bigger hole in the ceiling so the plug and existing wire will fit inside the celling.
| dimensions | 13 x 13 x 3 cm |
KF20 Optical Smoke Alarm
Free delivery between 31 Mar – 3 Apr
KF20 Optical Smoke Alarm
Free delivery between 30 Mar – 2 Apr
Kidde Kf20 Mains-powered Interconnectable Optical Smoke Alarm 230v
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Replaced old alarms which are discontinued as described.This alarm was shown as the best replacement for one that had been discontinued & was similar in fitting & function. So far its living up to what was advertised. Very pleased
Well built alarm. I've switched to optical alarms as we've had issues with ionization alarms false-triggering - usually at three in the morning. Too early to tell for this one, but happy with product in general
I tried to used the same screw hold as the old one but a slight modification in the ceiling was required for the plug to fit inside the base plate I.e. A bigger hole in the ceiling so the plug and existing wire will fit inside the celling.
Replaced my discontinued BRK 670 MBX smoke detector with ease. Came with adapter for easy replacement to the current wiring so I didn’t need to fully rewire the alarm. I just switched the adapter and replaced it. Fitted perfectly and the fitting took under 30 mins easy. Much recommended.
Full compatible with a previous optical smoke alarm installed a long-time ago. Very easy to take off the old item and replace with the latest technology. Literally took minutes.
Probably this is good product but not for me. When I read the instruction I understood that it is too complicated to install. I asked my my experienced neighbour to help, and after reading of the instruction he told me that I bought a wrong product : it is too expensive, and also I can't install this myself without an assistance of a professional electrician that would cost me a lot of money. My neighbour went to the shop and bought for me a right thing: a smoke alarm (that is four times cheaper) that I installed myself with no problem. So I want very much to return this product back to the selltr. However I do not know how to do this. Could you help me, Please?
These 2 alarms were replacements for 2 that were fitted appropriately 10 years ago. I was able to use the old cradle so was easy to fit with minimum disruption and a fresh new look white plastic. Very happy and would use your services again.
Bought two of these to replace the old Firex alarms that were in the house. Was able to use the same fittings - so very easy to install. They are mains alarms with back up batteries, the only difference between these and the old ones is that these have a replaceable 9v battery rather than rechargeable ones.
| dimensions | 13 x 13 x 3 cm |
