Carbon Monoxide risk from boiler

Philip624

We have moved into a property where the boiler,a worcester boiler is situated within a cupboard in the room intended for the kids. Due to concerns over carbon monxide we have looked into moving the boiler into the loft. To do so we need to lay boards in the loft and the flue and water tank will also need moving. All of the quotes we have had are quite expensive and we are not sure we can now afford to do this. The boiler is serviced annually, and we have a detector, and the boiler is within a cupboard.

How great is the actual risk of Carbon Monoxide poisoning. The boiler is only a few years old and is serviced and we have the detector. Should this be enough to give us peace of mind? What are peoples views on this. Are some detectors more efficent than others?

Mr_Warren_2

Why don't you call Worcester Head Office........in Worcester and ask them the question.

dan23uk

the risk from carbon monoxide (Co) poisoning from a boiler only a few years old is quite small, but could still happen.

the boiler will be 'room sealed', which means it is entirely sealed from the room, and takes the air it needs from combustion directly from outside, as opposed to older 'open flued' boilers which require air from the room to work sufficiently, and therefore more likely to have problems releasing carbon monoxide into a room.

if the boiler is in good condition and is serviced regularly, you shouldn't have any problems, as long as the case seals are in good condition and the flue is sealed properly through the wall. the integrity of the case seals should be tested as part of the annual service.

as for your detector, make sure it is a battery operated one, not mains operated, and it should also have the british standard 7860 mark on it.

hope this is of some help

dan

salthegal

can I ask why you recommend a battery detector over a mains one?

Philip624

powercuts...at a guess...

dan23uk

spot on, if there was a power cut in the night, and the boiler started leaking carbon monoxide, the alarm wouldn't go off.

also, never ever get the little sticky on things that change colour if there is carbon monoxide in the air, because of a) no audible warning, and b) they are too slow changing colour/would be too late to realise (not wanting to worry anyone of course)

bestyman

I was corgi registered years ago and a main part of my job was gas safety inspections.
I would advise you not to worry, modern boilers are very safe and if it is checked annually the chances of it been a danger are next to impossible.
Im sure the other plumbers on this board will agree with me

Re Detector : If there was a power cut the boiler wouldnt light so no chance of poisioning ;o)

Dead_Eye_Jones

Our boiler is in a cupboard, the inspector came round and said by modern standards our setup would not be allowed. However as it was in place already it did not have to be changed, he checked the ventilation and passed it. He pointed out that the cupboard must have good ventilation - it has big holes in the top!

CO is the result of incomplete combustion of gas, ie when there is not enough oxygen C will combine with one O and not two, CO2 is the harmless usual biproduct of combustion, its the prefered stable product but when there aint enough O then CO will be the result. Therefore ventilation is the key... Im no gas man, just a chemist !

dan23uk

the ventilation required for modern 'room sealed' boilers is only for cooling purposes, as the air for combustion is drawn through the flue from outside.

only older open flued boilers need purpose provided ventilation for combustion, as they use air from the room for combustion.

for cupboard/compartment ventilation to be classed as up to standard it must conform to various points, such as the holes in the vent must be between 5-10mm, and there must be no fly screen covering the vent as dust can build up and block the vent easier, and you should have 2 vents, on high, one low, for air flow purposes.

lots of boilers nowdays are very efficient and will not require any ventilation at all. each boiler is different, but the information on air vents etc can be found in the manufacturers instructions/manual

just to confirm, for a modern room sealed boiler, the ventilation of a cupboard/compartment will have no bearing on combustion performance/carbon monoxide build up as it is meant soley for cooling purposes of the boiler

also, on the subject of detectors, it is true that if the power shuts off the boiler will not light, but if the gas valve is faulty it can pass gas to the burner or pilot injector, so i still maintain that battery operated detectors are a better idea

dan (corgi engineer)

bestyman

Dan,
So you have seen or heard of a new combi boiler light with no power to it ?
Sorry mate, its impossible.

moneysavingplumber

Most modern room-sealed boilers work on negative pressure now, which means the risk is miniscule even with faulty case seals, most fatalities as a result of this problem (which is rare) as far as I know, were on positive pressure models, like the Potterton Profile (which means the pressure pushes out against the case as opposed to sucking). CO detectors are usually only fitted where there is considerable risk, i.e. conventionally flued boilers.

Bestyman is correct in saying a modern boiler won't light without power, and a gas valve letting-by isn't a CO issue anyway, as it will almost certainly be a spark ignition as opposed to permanent pilot on a modern Worcester so the boiler won't stay lit on the strength of a faulty gas valve, it will usually be evident by an explosive ignition in the mornings. The only issues are whether or not a mains operated alarm automatically resets after a power loss, and whether battery operated models all have a warning alarm when the battery is low. These are all pretty pedantic points anyway, just keep it properly serviced regularly as already stated.