Three-way valve
Try these before taking it apart
Steam and hot water from the wand but nothing, or only a dribble, from the group usually means scale is lodged in the three-way valve behind the group. The retailer Whole Latte Love tries these first.
- Run water from the wand, and flick the brew button on and off a few times while it runs.
- Backflush.
- Descale. For this fault the retailer sends the solution through the wand only.
The retailer's yardstick for a healthy machine is about 180 ml from the bare group in about 20 seconds. It says the valve failing outright, rather than clogging, is very rare. If the valve blocks again soon after cleaning, the boiler holds loose scale and needs opening.
Taking the valve off is the next two screens. Gaggia's manual does not cover this, and its safety booklet says repairs are only for a service centre authorised by Gaggia.
Take the valve off the group
A retailer's method (Whole Latte Love), filmed on the 2019 machine, with the key size from the 2019 Classic service manual. The retailer says the process is the same on every version.
- Unplug, go cold and take the top cover off.
- Free the pump: mark and pull its wires, pull the return tube off, undo its two mount screws and lift it aside on its hoses.
- Squeeze the spring clip on the rubber hose on top of the valve, slide it up and pull the hose off. Pull off the coil's connectors and the earth tab.
- Undo the two screws that hold the valve to the back of the group with a 4 mm hex key.
- Lift the valve out. Two O-rings sit on its mounting face: keep them with it.
Clean it on the bench and refit
The retailer's method, continued.
- Undo the nut that holds the coil on the stem and lift the coil off. Note which way its terminals face.
- Open the valve at its stem. A spring and a plunger are inside: do not lose them.
- Clear the narrow central passage. The blockage is usually there, not in the cavity you can see. Compressed air works best; otherwise a paperclip and a torch.
- Soak the metal body in descaler. Take the O-rings off first and keep plastic parts out.
- Reassemble with the coil's terminals facing as they were. Hold the coil while you nip the nut.
- Refit the valve with both O-rings in place, starting each screw on the key. Then the hose and clip, the connectors, the pump and the cover.
The 2019 service manual gives 5.5 Nm for the two valve screws.