Have worked in 3 bedrooms lately all with gas boilers in built in cupboards after they have replaced existing boilers, its always worried me about CO leaks in bedrooms or lack of air for combustion.

Should i advise customers about gaps under floor for air or gas vents and a CO detector.

Ive just been fitting shelves in the space left after the old boiler and tanks are ripped out.

The air for combustion is drawn in through the flue.

As said it’s drawn through the flue although a CO detector would be advised. IIRC you can get them free from somewhere.

Usually the manufacturer recommends a small grille through cupboard door or wall for ventilation into the main room so the cupboard doesn’t overheat, but most combis are “balanced flue”, ie have a dual flue where air is drawn in one tube and out the other, so no gas worries.

All modern bikers are negative pressure so any leak will suck air in rather than expel CO out. Potterton Netaheat boilers, which were a revolutionary 70s design* using a fan for the first time (to achieve 78% efficiency), were positive pressure and a have killed a few people with CO leaks, hence positive pressure boilers are no longer allowed.

NB We have a Netaheat and it’s still going string after 25+ years.

*The Potterton NetaHeat won the Institute of Domestic Heat Engineers first ever award for excellence.

Another random factoid, my cousin in law designed the heat exchanger in the Netaheat…..

Condescending boiler is condescending.

Nice. That needs to go in the Arrrgghh! My Eye! thread, Shirley?

At least give me a minute!

All modern bikers are negative pressure

Yes, I see that in this forum quite a lot. I wouldn’t say all of them though.

I wouldn’t say all of them though.

I’m sure I read somewhere that you couldn’t have +ve pressure domestic boilers anymore, but can’t find a reference for it…

Hmm, I should know this…

Boilers must be room sealed (combustion air drawn in through concentric flue) but I think CO sensor required in bedroom (well room boiler is mounted in). I was in a meeting about just this the other week…. Should be linked with smoke detectors also (if fitted).

Non room sealed no longer allowed to be mounted in bedroom (due to risk of CO poisoning).

footflaps – Member
I wouldn’t say all of them though.

Reading failure there….

Read the whole quote again footflaps.:D

Read the whole quote again footflaps.:D

🙂

All the bikers I know on here are very much +ve pressure – hot air venting from the top and seemingly all of us terminally flatulent as well

… as for condescending boilers, I think as long as the flue’s not snooty they should be OK

what i do like about this forum is the complete and utter bulls poo that some posters put up as though its gospel. a combi can go in any room.. restrictions are in place for most bathrooms re positioning eg not over the bath mostly but each boiler has specific manufacturers instructions that mustbe followed.

i d say its a pretty even split bare on the wall and in a cupboard or wardrobe. old airing cupboard probably the most popular bedroom site. again a combi in a cupbaord or enclosed space has ventilation requirements the manufacturers instructions will clearly detail these though rather than physical vents in doors the requirement will be arounds space at the sides and at the front and above and below the appliance

combis always use the flue for air ( usually the outer of the two tubes in the flue) and combustion products in the inner tube. the couter cover often provides an airseal around the inner compartment should there be an escape of products of combustion/gas.

unless you are a competant person as defined by the local authority you have no business advising anyone on the need for gaps under the floor for air or gas. advice on installing an audible co alarm correctly installed can save a life (as one of mine did just this weekend)

unless someone can quote me a BS reference i ve a strong belief that it is not compulsory to fit a co sensor in any room where a boiler is installed nor is it compulsory to fit fire alarms nor link them to such alarms..

Gas condesending boiler

I had one of them but I had to get ris of it, it for forever putting me down and patronising me.

Building regs mean that any new build or notifiable works require wired smoke detectors but beyond that, no, there’s no requirement for them and no specification beyond landings and kitchen.

(source: just got them installed after extension was built).

CO detectors are just good common sense.