La Marzocco · 2, 3 and 4 group
La Marzocco GB5 S — PSSR examination & servicing
GB5 S machines are used in high-volume cafés, hotel breakfast rooms and flagship multi-site operations nationwide. The engineer carries out the statutory PSSR examination, the front-end service and the water treatment on this model — a standalone examination is £295 + VAT, or £695 + VAT with the service included.
Quick answer
Does a La Marzocco GB5 S need a PSSR examination?
Yes, if it operates in a workplace. It carries a single steam boiler with its own protective devices, which is the pressure system in scope. Steam is a relevant fluid under PSSR 2000 and steam systems are covered at any pressure and any volume, so the boiler must have a Written Scheme of Examination and be examined periodically by a competent person.
- Examination only
- £295
- With service
- £695
The machine
Why the GB5 S matters to the La Marzocco owner
The high-volume La Marzocco — a saturated-group machine with a separate steam boiler, built for sites that cannot afford a queue to slow down.
In practice you will find it in high-volume cafés, hotel breakfast rooms and flagship multi-site operations — which shapes what the examination looks like on site: how the machine is accessed, how long it can be offline, and how much scale it has accumulated.
On the day
- The steam boiler is drained and inspected internally with an endoscope for scale, corrosion and weld condition.
- The safety valve, anti-vac valve and fittings are checked and tested.
- The pressure gauge is verified against our calibrated test gauge, not against itself.
- A 3 group boiler holds more water than a 2 group, so the drain, refill and heat-up all take longer — allow the full appointment window.
- The Written Scheme of Examination names the vessel and the protective devices it covers.
Typical rates for this model
- Standalone PSSR examination
- £295
- Service + PSSR bundle
- £695
- Certified safety valve, if it fails
- £55 + VAT
- Water filter, fitted on a visit
- from £107
- Grinder calibration & deep clean
- £89
- If it does not pass
- Explained in writing
All prices exclude VAT. The additional drain and heat-up time a 3 group boiler needs. We confirm the exact figure on the call.
Filters are fitted on site by an engineer and are not posted out. The filter price applies when ordered with a PSSR examination, service, call-out or water test; booked alone it is charged at the standard call-out.
What we see on this model
- The steam boiler and its protective devices are what fall inside the Written Scheme.
- The saturated group design makes the boiler slow to drain and refill, which is the main reason this takes longer than a Linea PB of the same group count.
- Genuine La Marzocco parts cost roughly double the generic equivalent — the certified boiler valve alone is about £36 before fitting — so parts are quoted at OEM cost rather than the standard rate.
- Dual boiler, saturated groups, dual PID; 2-group: 7 L steam / 3.4 L brew, 5200 W; 3-group: 11 L / 5 L, 6800 W; 4-group: 15 L / 3.4 L x2, 8300 W. Released March 2021, replacing the GB5 (discontinued March 2021). Serial breakpoints: GN000493 (revised L192), GN004843 (Acetal grub screw).
- A one-off annual service on a traditional La Marzocco runs £350–£650 including the manufacturer kit — the engineer fee alone is £200–£350, and a 2-group front-end kit is around £120. Dealers sell annual support at £800–£1,100 for a Linea PB or Classic S and £1,200–£1,650 for a KB90 or Strada. Our published bundle covers labour and the examination; the kit is charged at cost with the visit.
Verified boiler data
What is actually inside this machine
| Configuration | Steam boiler |
|---|---|
| 2 group | 7.0 L |
Manufacturer's published boiler capacities. Where a maker publishes no figure we say so rather than estimate.
Service interval. LM USA group-specific PM kits: 3 & 9 months (GB5S.3.x) replace group gaskets and diffuser screens; 6 months (GB5S.6.x); 12 months (GB5S.12.x). Kits are ordered per group count, e.g. GB5S.12.2 for a 2-group. Water spec checked at every visit
What a service covers
- ›Group heads overhauled — gaskets, diffusers and shower screens replaced
- ›Steam and water valves rebuilt, anti-suction valves cleaned and internal O-rings changed
- ›Water tested for total dissolved solids and the inline filter treatment renewed
- ›Level probes descaled, safety switches tested and boiler temperatures logged
Fault finder
What actually goes wrong on a La Marzocco GB5 S
Owners usually call us with a symptom, not a diagnosis. This is what that symptom most often turns out to be on this machine, and what putting it right involves.
| Symptom | Usual cause | What fixes it |
|---|---|---|
| Heating cycle stops but the display shows a fixed (false) boiler temperature. | Firmware bug on GB5 X-S builds before 1.0.0-RC14. | Update to firmware 1.0.0-RC14 via the La Marzocco Pro app; machines built before/without IoT hardware load it from a FAT32 USB stick (TB 187). |
| Play between steam knob and insert; knob feels loose or the grub screw strips. | Brass slotted grub screw I.4.005 and old knob locking screw I.1.135. | Acetal hex grub screw I.6.027 in production from GN004843; revised knob locking screw I.1.135 for units built after 12/02/2025; both are in retrofit kit 1026. If play persists, replace insert and knob together (TB 202). |
| Steam or water weeps at the vacuum breaker and the boiler is slow to seal on heat-up. | The anti-suction/vacuum breaker is a wear item; LM replaced it with a 360-degree body and states the SMA version B.2.029 has a significantly longer lifespan because it does not rely on gravity. | Fit the revised L192 anti-suction valve used from GN000493, or retrofit the SMA breaker B.2.029 with a new copper washer (TB 174). |
| Leak around the portafilter and falling brew pressure at the group. | Group gasket hardens and the diffuser screen/steam-flush holes coke up. | Replace group gasket H.3.004, shower screen F.3.040.01 and diffuser screw A.5.110 on the 3/9-month PM. |
| Steam wand drips at rest and steam volume falls away. | Steam-valve seat and O-rings wear; LM schedules a steam-valve rebuild at 6 months. | Rebuild the steam valves with the 6-month PM kit (GB5S.6.2/6.3/6.4). |
These are faults documented for this model, not a generic list.
Common parts
Common parts for the La Marzocco GB5 S
The components most often replaced on this machine, listed by reference number, as a reference for engineers and owners identifying a part.
| Part no. | Description |
|---|---|
| #2102 | Parker 3 Way Grp Solenoid Valve 24v (Plus 3 housings in) |
| #2841 | Element Protection Thermostat - Original |
| #0398 | Lucifer 3 Way Grp Solenoid Valve 230v (Ruby) |
| #18281 | Parker 3 Way Solenoid Valve 24v |
| #0450 | PARKER 3 WAY GRP SOLENOID VALVE 230V (RUBY) |
| #23371 | PARKER 2 WAY INLET SOLENOID VALVE 230V |
| #29950 | PARKER 3 WAY SOLENOID VALVE 24V |
| #0020 | Pump Head Rotoflow |
| #0093 | Sirai Pressure Switch |
| #1497 | Parker Pressure Switch |
| #1578 | Solenoid O Rings Bag Of 100 |
| #1586 | Shower Plate 52 X 5mm |
Parts most often needed on this model
| Part | Number | What it fixes |
|---|---|---|
| Group gasket | H.3.004 | Hardens and leaks; 3/9-month item. |
| Coffee shower screen, logo, H6.5 | F.3.040.01 | Cokes up and restricts flow. |
| Diffuser screw M6x10 stainless | A.5.110 | Replaces L106/V; needed for correct steam flush (TB 156). |
| Vacuum breaker / anti-suction valve | L192.02 | 12-month replacement; revised L192 is drop-in. |
| Knob grub screw, Acetal hex | I.6.027 | Supersedes brass I.4.005 that strips. |
| Knob locking screw | I.1.135 | Revised version tightens from the rear. |
Questions
GB5 S questions, answered
How a boiler of this size is examined, how often, and who carries the duty — see the complete PSSR guide.
0208 037 9340
How much does a PSSR examination cost on a La Marzocco GB5 S?
A standalone examination is £295 + VAT, because the additional drain and heat-up time a 3 group boiler needs. Combined with a front-end service it is £695 + VAT, which is what most high-volume cafés, hotel breakfast rooms and flagship multi-site operations choose, since the boiler has to be drained for the examination either way. The bundle on this range is higher than our standard ladder because its service parts are proprietary: a manufacturer service kit and an OEM safety valve cost several times the generic equivalents, and on some models there is no generic equivalent at all. We confirm the exact figure on the call.
How often does a La Marzocco GB5 S need examining?
The Written Scheme of Examination sets the interval, and for a commercial machine used in high-volume cafés, hotel breakfast rooms and flagship multi-site operations it is typically 12 to 14 months. A 3 group boiler holds a larger volume of water, so scale accumulates faster than in a smaller machine on the same duty and the scheme usually sets the shorter interval.
How long does a La Marzocco GB5 S examination take, and what happens on the day?
A 3 group boiler holds more water than a 2 group, so the drain, refill and heat-up all take longer — allow the full appointment window. The visit runs: the steam boiler is drained and inspected internally with an endoscope for scale, corrosion and weld condition. the safety valve, anti-vac valve and fittings are checked and tested. The gauge is then verified against our calibrated test gauge, the system is pressure tested and held, and the machine is re-assembled, refilled, heated and function tested. The Written Scheme of Examination, signed report and asset record follow within 48 hours.
Other La Marzocco machines covered
Call and we'll price your GB5 S on the spot.
Same-week appointments nationwide, the Written Scheme of Examination issued within 48 hours of the visit, and a fixed price agreed before we travel.