Recommend a CO Alarm

[SWH]

Our current CO alarm has toddled off to Silicon Heaven, so I'm looking for recommendations for a replacement.

Dead one was a Wickes effort, latest 6yrs, which is the same as the expiry/replacement sticker on the back. Perfectly happy to pop into Wickes on Saturday morning and get another one, but thought I'd see if anyone had any decent recommendations

[netherfield]

Kidde combination smoke and CO detector, or Honeywell SF450EN

[neil-c]

Slight deviation from topic but looking at the kidde combined smoke and co detector mentioned to replace old smoke detector but current one is mains powered with battery back up. Is there a combined detector with mains power

[Efbe]

An electrician came around our house recently to do some work.
Noticed that our carbon monoxide alarm was near the smoke alarm high up on the first floor.

He told us that CO is heavier than air and so starts from the ground up, unlike smoke starting from the roof down, so by the time our CO alarm was triggered we would all be dead... which is nice.

is this correct? should CO alarms be located low down on the ground floor?

[Tanguero]

CO is 28g/mol and has a relative density of 1.145 g/l @ 20c
Air is also 28g/mol has a relative density of 1.2 g/l @ 20c

So no - CO is very slightly lighter than air

[Efbe]

thanks tanguero

[SWH]

Honeywell SF450EN looks just the job, thanks