On 17/04/2011 22:07, Steve Walker wrote:

I don't know about this particular boiler, but I've often wondered
whether there is any great risk to poor combustion with most boilers
these days, as they are generally room sealed and under negative
pressure due to the exhaust fan, therefore they should be unable to leak
CO into the room.

I would have thought that the main worry would be increased fuel bills
and gradually reducing heat output.


Just FYI mine's under positive pressure from an inlet fan. But the
combustion chamber is completely enclosed by the fresh air plenum except
the exhaust - so leaks would be cold fresh air into the room, anything
combusted can only go out of the flue.

Andy