White Firex Smoke Alarm 4870 (Kidde, ) Dual voltage power supply with 230v mains power or 9v battery backup

I have to say these were hard to find but perfect for the job. We had our wired fire alarm installed in 2008 and had no idea that you needed to replace them. Only when one of the old units weas setting off the alarm did we realise that they should have been replaced 5 years ago. So I set about contacting companies to find a replacement for the "Firex 120-1123C". It wasn't until I Googled my old product did this one pop up and reading the review and question answers I purchased one first to check. After I found out they were right I bought the others. Very simple job to take the old one out and replace the unit and base cradle.Very happy with the purchase.

I decided to replace my existing Firex 120-1123c units, one upstairs and one downstairs, hard wired, inter-connected as I have been in the house for coming-up 10 years. Although they weren't showing signs of fault, that is the recommendation. After much googling and reading, these were the closest I could get but I wasn't sure if, when they arrived, they would require a re-wire of the ceiling connector. I even rang Kidde who couldn't be sure as my previous model was not on their docs. The answer is, they fit perfectly. It took me about 10 mins to do both alarms - get a chair, get the old one off, fit the backup battery to the new one, fit the new one to the ceiling-mounted housing and twist it to lock. I didn't even have to replace the ceiling housing that the main smoke alarm box 'screws' into, but these units come with a full ceiling mount and wiring loom if you do need new stuff.

I have wired smoke alarms which are earlier versions of the current model. It was recommended to replace my older alarms after 10 years. I was concerned that they may not be backwardly compatible. They are. No electrician required - merely unscrew the alarm from the base, unplug lead, and replace with the new version. (Do not forget to isolate the power supply beforehand - fuse box/circuit breaker). Over the years these have given me no trouble. No false alarms and easy to replace backup battery. I have three newer alarms of a different make which have gone off accidentally several times and deactivating them in a hurry by prising off the cover (often in the middle of the night) is not as easy as unscrewing. In summary a reliable, backwardly compatible alarm with easy to remove covers (unscrewing). Great value and highly recommended. Prompt service from supplier.

I purchased two of these to replace some existing interlinked Kidde alarms that after 4 years were starting to go off randomly.These seem good, I had to change the base and wiring connections but it's all quite simple and well defined in the instructions.So far no problems, no alarm going off in the middle of the night for no reason or anything like that but time will tell.

Perfect transaction. Could not be better. Arrived next working day - very well packed and very well priced. This design hasn't changed for at least 17 years to my certain knowledge as I bought these to replace the originals in my house built in 1995. They just swapped over in minutes with the connector remaining exactly the same and fits the new alarm perfectly. They're now called KF1 whereas they used to be 4870 and 1240C before that. An Ionisation type alarm. Comes with Alkaline battery in the pack.They do an 'Optical' matching item called KF2....they recommend having both types and I'd agree with that.....it's not just sales patter.Recommended.

Excellent product replaced my existing smoke alarms which were installed in my home by the builder from new, just clicked out old one, reconnected wire connection and it even fitted back into original mounting on ceiling. Loud bleep when activated and good led light system to tell you there is power and it is monitoring.

Purchased these to replace same style smoke alarms at home that were well out of date and starting to play up. I chose these as I didn’t have to replace the base but simply unclipped the unit and new units fitted perfectly. No hassle and inexpensive solution to replacing existing smoke detectors.

Great purchase. Peace of mind.