.......When you turn the APU on, turn the air bleed ON, and leave the packs off for a minute. The tank pressurises much quicker.
Good idea to do this anyway i.e. don't hit the APU with full air loading when it has only just started because that causes heat stress on the turbine. Better to switch the load on in stages, allowing a few moments between selections for stabilisation.
One day I will learn to check the tap BEFORE I put soap on my hands........
