Do I Need a Dedicated Carbon Monoxide Alarm?

  morddwyd 11:38 22 Oct 2015
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Answered

When I last replaced my smoke alarm I bought a combined CO and smoke alarm.

I know it works in both modes as I've had workmen in using solder!

My dedicated CO alarm has now died of old age. Do I really need a dedicated CO alarm or can I safely rely on the dual purpose one?

  wee eddie 11:47 22 Oct 2015

We stuck a Dedicated Monoxide Alarm, in my Mother's Flat, immediately adjacent to the Gas Boiler.

The cost was tiny and it's positioning was different to the Combined Smoke/Co Alarm as the two things behave differently.

  morddwyd 12:54 22 Oct 2015

"Alarm as the two things behave differently."

How?

  wee eddie 14:50 22 Oct 2015

CO is a heavy gas and once its left the warm environ of the boiler that created it, tends to fall. Smoke particles from a fire tend to rise

  Govan1x 16:37 22 Oct 2015

The fire service used to fit Smoke alarms free but not sure if they still do. Worth a Google I suppose.

Quick look says that they still do.Or some of them still do.

  morddwyd 19:15 22 Oct 2015

"CO is a heavy gas and once its left the warm environ of the boiler that created it, tends to fall. Smoke particles from a fire tend to rise"

I'm well aware of that, but that doesn't explain how a CO detector in its own discrete enclosure behaves differently to a CO detector sitting alongside a smoke detector.

"The fire service used to fit Smoke alarms free but not sure if they still do. Worth a Google I suppose."

My fire service still does, but I'm not sure how that's relevant to the need, or not, for a separate CO detector.

  wee eddie 20:08 22 Oct 2015

Smoke Detector on ceiling. CO Detector at nnostril height

  wee eddie 00:31 23 Oct 2015

Good point

  morddwyd 07:31 23 Oct 2015

But many boilers are on the first floor or higher (My neighbour's is in the loft.). By the time it gets to "as low as possible" dangerous concentrations may have already built up.

Since I already know my alarm works in it's current position, the question was not about positioning, but whether I need another one.

  Bazzaman 08:48 23 Oct 2015

As I understand it, for practical purposes CO tends to mix with the air (because, although it is a different "weight" it is only very slightly different and so readily mixes with even slight air currents around the home).

Read more here: click here

  BT 08:50 23 Oct 2015

But many boilers are on the first floor or higher

As most modern boilers are a sealed system drawing combustion air in from outside and venting outside as well, in theory they shouldn't release CO into the room. I think an alarm should be positioned in the room where the boiler is but also in other areas, your living room and bedroom as well. CO alarms are now much cheaper than they ever were ( less than £20). Many now run on AA batteries rather than expensive PP9s. CO alarms have a limited life span after activation and cannot be reset.

Better safe than sorry

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