The Pressure chamber varies in appearance from one model or make to another,
but they are all situated on the lower part of the outer container either front,
rear or under it and they are connected to the pressure switch by means of a thin hose.
Air is trapped in the chamber as the machine fills with water and is forced up the hose,
(the more water the greater the pressure) until the pressure inside the hose triggers the
switch and so turns off the fill valve. (The one illustrated is an extension to the sump
and was fitted on the Hotpoint WMA range)
