La Marzocco 40 Amp Four Group Contactor portofino parts brasilia portofino gradisca century boiler Accumulator tank cuts short cycling and Accumulator tank cuts short cycling and water hammer Recommend a qualified technician This 40 amp contactor works in conjunction with the pressurestat to regulate steam boiler temperature on four group La Marzocco machines only it's the high current relay that switches the steam element on and off A contactor with pitted or burnt contacts will cause the steam boiler to run hot or cycle erratically even with a good pressurestat listen for a buzzing or chattering contactor as an early warning sign before it fails completely