At the Pull Down at Barefoot Coffee the Pavoni pulled shot after well temped shot for two hours. The key was the pressure gauge from Orphan Espresso with an espressme adaptor.
Using your palate as your guide, determine the ideal bar reading for your coffee. In the case of Barefoot's Element it was a cool .5 bar. Warm the machine to the desired bar setting, (if you get to 1.0 bar, with steam pouring from the safety valve, you overheated), start pulling the shot, but turn off the machine during pre-infusion and finish pulling the shot. When you are almost ready to pull the following shot, turn on the machine and repeat the process.
When the machine needs a refill, wait until the pressure gauge is at 0 then slowly and carefully remove the cap and add water, having left the boiler at least 30% full.