Gas Ventilation , Do i need a new vent in a wall when i already have one in suspended floor?
If your gas boiler was passed by the gas fitter with the floor vent then the vent that the cavity wall fitter is suggesting is probable nothing to do with the gas boiler, A cavity wall fitter is not qualified to say either way if you need a vent for your boiler Gas appliance that do not have enough air to burn will start to burn the air in the room it is in, and because you cannot have a vacuum carbon monoxide will swap places with the oxygen that has been burnt with possible fatal consequences
