Fix: See Above
The brew groups differ subtly between models. The brew group housing, upper and lower pistons, gear box, shower screen, gaskets, stabilizing rod for housing, gear, movable arms (left and right) and the top cover are identical across all models, except the ENA Micro Line. The ENA Micro line contains a brew group that mirrors the brew groups in the other lines, just in a smaller form. The drain valve contains 3 nut seals, a spacer, drain valve body containing two O-Rings, extension arm, fluid nipple and spring/rod connection. The O-Rings in the drain valve are the same as the subsequent models, but the components of the drain valve are different sizes, as well as, the piston gaskets and all other components.
The C, E, F, S, X models share the same drain valve. It consists of a valve body with 2 nut seals inserted on opposite ends and 2 O-Rings, a fluid nipple containing an O-Ring, a discharge valve, a spring and rod mechanism that directs the flow of water and a 90 degree hose connector. The valve is secured to the housing by a hair pin connection to the fluid nipple on one end and a hair pin clip to secure the 90 degree connector to the valve on the other end. This connector serves as the inlet for the hot water to enter the brew group to brew a shot. There is a hole above the cut out for the pressure hose. A T15 Torx screw secures the drain valve to the machine.
The GIGA, J, Z, ENA models share the same drain valve, which differs from the aforementioned models. It contains the same nut seals, valve body seals, spring and rod mechanism, and fluid nipple; however, it contains an extension arm with an O-Ring that is inserted into the top of the drain valve instead of the 90 degree connector. This extension arm serves as the water inlet connection to the brew group to complete the brew cycle. Note: The two adjacent Torx screws that secure the brew group drive shaft are T20. The screw to secure the drain valve in the J-Z (Old)-ENA models is a T15 Torx Screw. In the GIGA and new Z6-Z8 is a T10 Torx screw. The thinner T10 Torx screw in new models does not secure the drain valve as well as the T15 used in previous models; thus, causing the drain valve to loosen with increased use (we found it occurs around two years). Also, the brew group guides were changed 3 times over the years. The newest version is made of cheap plastic, which is too light to properly secure the brew group to the gear motor, causing the brew group to loosen over time.
The riser tubes and coffee spout connectors (the piece that connects to the riser tube with a pressure hose or silicone tube) differ for each model. Please check which connection your machine contains before ordering.