When a manufacturer has not specified the maximum amount of CO in the flue of a condensing boiler, the HHIC states that the maximum amount of CO must not be more than 350 PPM (Parts Per Million) and the Combustion Ratio is less than or equal to 0.0040.
We would be most interested to receive comments about this (do email office@co-gassafety.co.uk).. CO-Gas Safety considers that this is a retrograde step and that a maximum of 200 PPM of CO is achievable by most manufacturers immediately and a lower amount should be possible soon.
There is a link to product instructions see http://www.centralheating.co.uk/installation-manuals
Comment by OPGO Organisation of Professional Gas Operatives www.opgo.co.uk/ 22.05.13
”For the last 20+ years the CO action figure in boiler emissions has been 200ppm. OPGO see raising the action limit as potentially dangerous and have received no logical explanation, on gas safety grounds, as to why HHIC would wish to increase this action limit.
In OPGO’s experience, increases in technology and the fact that all RGEs who now work on boilers have been assessed as competent to use an electronic combustion gas analyser, the action figure should be lower, not higher. Many boilers already achieve CO emission figures of less than 100ppm, so in our opinion that is the figure the industry should aspire to achieve as soon as is practically possible.’
Luckily Amy Rooke and her child escaped harm as they were out at the time of the explosion. However, we urge everyone to consider this danger and visit http://www.hse.gov.uk/services/localgovernment/boilers.htm