Gaggia Classic Pro: Parts & Specifications Reference
Field-measured component specifications for the Gaggia Classic Pro (2019+). Gaggia publishes no internal component specifications in consumer documentation. All dimensions below are sourced from physical measurement and cross-reference with known aftermarket parts.
Group Head
| Component | Specification | Notes |
|---|
| Group head diameter | 58mm | Industry standard — widest aftermarket compatibility |
| Group head material | Brass (chrome plated exterior) | Higher thermal mass than stainless |
| Gasket OD | 58mm | — |
| Gasket ID | 49mm | — |
| Gasket thickness | 8.5mm | Use silicone, not EPDM — see gasket guide |
| Shower screen screw | M5 × 8mm Philips | Brass into brass — do not overtighten |
| Shower screen OD | 50mm | Classic Pro screen ≠ pre-2019 Classic screen |
| Portafilter lug spacing | Standard 58mm commercial | Compatible with IMS, VST, La Marzocco baskets |
Boiler
| Parameter | Value |
|---|
| Boiler material | Brass |
| Boiler volume (approx.) | 300ml |
| Heating element power | 1425W |
| Brew temperature (pressurestat default) | ~100–105°C |
| Steam temperature | ~120–125°C |
| Idle boiler pressure | 0.9–1.1 bar |
| Safety valve relief pressure | ~1.8 bar |
| Descaling concentration limit | 1.5g citric acid / 100ml (EPDM seal protection) |
Pump
| Parameter | Value |
|---|
| Pump model | ULKA EP5 (or equivalent) |
| Pump type | Vibratory (solenoid piston) |
| Rated pressure | 15 bar |
| Power consumption | 48W |
| Voltage | 120V AC, 60Hz (North America) |
| Flow rate (unloaded) | ~320ml/min |
| Replacement part | ULKA EP5 — direct fit, ~$20–30 |
OPV (Over-Pressure Valve)
| Parameter | Value |
|---|
| Factory set pressure | 11–12 bar (varies by production batch) |
| Recommended adjusted pressure | 9 bar |
| Adjustment screw thread | M6 × 1.0mm |
| Pressure change per full turn | ~0.8–1.2 bar (counterclockwise = lower) |
| Spring rate (approx.) | ~0.8 N/mm |
| 9-bar replacement spring | Available from IMS, Shades of Coffee, various suppliers |
Steam Valve & Wand O-Rings
| Location | OD | ID | Cross-Section | Material |
|---|
| Steam valve stem | 10mm | 7mm | 1.5mm | EPDM |
| Steam wand base fitting | 12mm | 9mm | 1.5mm | EPDM |
| Solenoid valve body O-ring | 14mm | 11mm | 1.5mm | EPDM |
Steam Tip
| Parameter | Value |
|---|
| Hole configuration | 1-hole (factory) |
| Bore diameter | 1.0mm |
| Thread | M10 × 1.0mm (fine pitch) |
| Compatible upgrade tips | Any M10×1.0 tip: 2-hole, 4-hole, Rancilio Silvia single |
For repair procedures using these specifications, see the Gaggia Troubleshooting Hub and Gaggia Master Maintenance Guide.
Specifications sourced from field measurement and cross-reference with aftermarket parts. CoffeeFixManual is not affiliated with Gaggia or Saeco. Specifications may vary by production batch.