The manufacturer stated that the vent should not be under or too close to the appliance. A bit sloppy. The Installer fitted at A on the scale-model sketch within one metre. Burley say not less than one metre which B on the sketch shows. Would B have made a difference in the tragedy. It is obvious that it could not have made a jot of difference but unfortunately this could not be tested in court. The inspector would have lost than one.

The precise location of A is not stated, simply less than one metre. That is sloppy reporting and it has to be assumed also it means to the nearest part of the appliance. As I say it would have been kicked out: Would you risk your family's life with B ? Of course not.

Regardless of that there are far too many other ways air could have reached the room. Even a lounge/hall door part open and junk-mail holding the letter box open. Trickle vents on windows (newish house then). Air stratification due to convection currents with air rising and cold air pushed down. To suggest the vent as a cause is totally unsafe.

It may have been responsible of course due to poor appliance manual design. It should all have been investigated but it was not. Counsel would have hauled the manufacturer's designer into court and more besides.

The absence of baffles in the vent is also unsafe. It may have been a still day (did anyone check). The alleged draught-busting benefits of baffles is illusory, except with the Arrest-Air-Pro ventilator. Wind of course can pull air from a room when blowing across a vent as is now well established.