So my GS3 (AV model) is growing older - and like anything that combines heat, water, steam, pressure, electronics and complexity - some components needed replacements over time.

I start this thread for those who have purchased one and would like to know what may be in store for them. Note that my machine was a "fire sale" volumetric machine and thus did not have all of the latest updates since devised by LM. Albeit most of these I applied myself.

Vacuum breaker - replaced or rebuilt every 2 years - this is by far the most prone to developing issues. New design (PN: L193) is better and highly recommended for those using the old design (old PN: L190). Note that the new design - the silicon tube (PN: T.4.001) will dry out near the boiler so spares would be kept (better yet - it is sent from LM rather long - coil the rest in a cool area and so that you have spares when you need to shorten the dry hot side). Keep spare o-rings (PN: F.2.019) handy for rebuilding a hissing breaker as well.

O-rings ~5 years - these are the Viton O-rings (PN F.2.014) that seal the boiler to the heaters and the heat exchanger. Small drops of water or evidence of evaporation near the heater are tell signs.

Steam boiler empty valve (PN: L164) ~5 years - this wears out. The plastic stops sealing and leaks from the handle. Can be Gerry Rigged to work a few months more, but is inexpensive. Leaks here are disastrous since this valve is right above the main wire harness. Any leak is wicked directly to the controller brain - a 500$ repair. So replace this 21$ part if at all in doubt.

Steam valve rebuild ~ 5 years - steam takes longer to shut of? Hissing even when not steaming? Easy rebuild kit (PN: B.1.004.K) has all the necessary O-rings (2 required PN: H.1.004) as well as the springs & slugs. First trying to replace the o-rings makes sense from a cost perspective.

Check valve (PN: B.2.008) - replaced 1 - 5 years - this is especially try for anyone who has a machine that does not have two check valves between the steam boiler and the tea mixer. A valve failure (open) on this pipe causes water to back into the boiler - causing the OPV to release water into the drain. A kit is available to double that check valve - highly recommended.

Hope this helps...

NB - I have spare seals for the top cover of the brew head - but never needed them - I don't open it much.

NB2 - lubrication - be very careful when replacing using lubrication on orings. Some petroleum based lubricants can cause orings to swell. The white food safe petroleum grease is especially good at causing orings to deform. I have had success with Superlube and heard good things about Dow 111.

What a great idea to let others know this level of detail. I am actually curious what is ahead for my LMLM. Expectation is that there will be a lower level of maintenance based on far simpler design than GS3

Good Thread! Nice to know what could fail and the necessary part numbers to rectify it. Thanks

Silicone based orings etc.. use vaseline (petroleum jelly), rubber use silicon based lube. The reverse causes the o rings etc.. to deteriorate.

Surprised how much required replacement in 7 years.

Excellent idea, Assaf. I agree with all you posted.

LM's 6-month and 1-year maintenance recommendations for the GS/3 may be found by following these links:

http://www.lamarzoccousa.com/wp-content ... nth-PM.pdf

http://www.lamarzoccousa.com/wp-content ... ear-PM.pdf

Note that La Marzocco recommends replacing the steam boiler OPV once a year. FWIW, I haven't replaced the OPV in my 7-year old GS/3, but in light of LM's recommendation I plan to do so soon. I have never heard of a GS/3 steam boiler OPV failure, but that doesn't mean it's not possible. The consequences are likely very bad for the machine and could cause physical injury to people. At about $84 a new OPV is relatively cheap insurance.

I would add a few less urgent items that may require replacement after 5-6 years:

- Button decals (more likely to be needed on AV model coffee button)
- Box enclosing the display and buttons (plastic disintegrates over time due to heat)
- Rubber gasket around group head (mine tore -- probably due to more frequent removal of the front panel than most owners would do.)

Other parts that I've replaced that may or may not need replacing on other machines:

- Boiler gauges (had to replace coffee boiler gauge; steam boiler gauge now not returning to zero and probably should be replaced.)

- Plastic portion of drain box (if plumbed in). Mine leaked around the hose barb, but that was probably due to excess stress on the fitting (i.e., my fault.) I was able to seal it with RTV, but eventually replaced the box (not easy to get the stainless trim off, which is glued on, but it can be done.) After a number of years with the new box, there are signs of deterioration of the plastic on the bottom and on the ridge where the vacuum breaker vents every time the machine is turned on. So far those areas haven't broken through, but it looks like they might do so eventually.

- Safety thermostats on boilers. One of mine cracked and lost part of the body. Not sure if that was due to deterioration or my striking it during maintenance.

DaveC wrote:Surprised how much required replacement in 7 years.

It's not surprising to me. Most of the seals and mechanical parts are located in high-heat areas and would be regular maintenance items on any espresso machine. Typically, a car will need replacement parts much sooner, and some items need service on a 6-month and annual basis. Why would your espresso machine be any different?

Simon345 wrote:What a great idea to let others know this level of detail. I am actually curious what is ahead for my LMLM. Expectation is that there will be a lower level of maintenance based on far simpler design than GS3

No Doubt less. The main difference between the LMLM and the GS/3 is the amount of extra piping, fittings and components that are dedicated to ensure that the time between pulls is ALWAYS Zero. Use tea water, make lattes, no exceptions. These extra fittings result in many headaches.

That said, vacuum breakers should be of a concern. But at least you know they'll be of the newer, kinder to your machine, type

Peppersass wrote:Excellent idea, Assaf. I agree with all you posted.

LM's 6-month and 1-year maintenance recommendations for the GS/3 may be found by following these links:

http://www.lamarzoccousa.com/wp-content ... nth-PM.pdf

http://www.lamarzoccousa.com/wp-content ... ear-PM.pdf

Note that La Marzocco recommends replacing the steam boiler OPV once a year. FWIW, I haven't replaced the OPV in my 7-year old GS/3, but in light of LM's recommendation I plan to do so soon. I have never heard of a GS/3 steam boiler OPV failure, but that doesn't mean it's not possible. The consequences are likely very bad for the machine and could cause physical injury to people. At about $84 a new OPV is relatively cheap insurance.

I wouldn't. It is unlikely to ever fail closed. It is a spring and seal. Springs never increase their coefficient. At worst, it'll become weaker.
Seals only deteriorate. At some point in time - it'll starts spilling hot steam. That will be time to replace it. My guess is LM are recommending this due to lawyers.

I would add a few less urgent items that may require replacement after 5-6 years:

- Button decals (more likely to be needed on AV model coffee button)

Half of mine are glued back on using contact cement....

- Box enclosing the display and buttons (plastic disintegrates over time due to heat)

My box is held together by duct tape!

- Rubber gasket around group head (mine tore -- probably due to more frequent removal of the front panel than most owners would do.)

Mine is okay - but I am careful with it. How does one replace that? Can it stretch over the group?

Other parts that I've replaced that may or may not need replacing on other machines:

- Boiler gauges (had to replace coffee boiler gauge; steam boiler gauge now not returning to zero and probably should be replaced.)

Early designs had the needle fit too loosely over the pinion. After mine moved out of adjustment I disassembled it, adjusted it using a Fluke pressure transducer and secured it to the pinion using a drop of CA glue - Haven't lost accuracy since!

- Plastic portion of drain box (if plumbed in). Mine leaked around the hose barb, but that was probably due to excess stress on the fitting (i.e., my fault.) I was able to seal it with RTV, but eventually replaced the box (not easy to get the stainless trim off, which is glued on, but it can be done.) After a number of years with the new box, there are signs of deterioration of the plastic on the bottom and on the ridge where the vacuum breaker vents every time the machine is turned on. So far those areas haven't broken through, but it looks like they might do so eventually.

At least two years my box had the bottom covered in silicone and the top in Epoxy. Otherwise it would leak through cracks.

- Safety thermostats on boilers. One of mine cracked and lost part of the body. Not sure if that was due to deterioration or my striking it during maintenance.

I am lucky on these - I guess. But one thing to remember is that most of the plastics have lost the plasticizers due to heat. So a small bump with a wrench - that would have gone unnoticed in the first 5 years - can now crack a pricy bit of kit. So as the machines age - grace in maintenance becomes important.

It's not surprising to me. Most of the seals and mechanical parts are located in high-heat areas and would be regular maintenance items on any espresso machine. Typically, a car will need replacement parts much sooner, and some items need service on a 6-month and annual basis. Why would your espresso machine be any different?

DaveC wrote:Silicone based orings etc.. use vaseline (petroleum jelly), rubber use silicon based lube. The reverse causes the o rings etc.. to deteriorate.

Surprised how much required replacement in 7 years.

What about Viton?

Also - in the thread about Cafelat Silicone Group Gaskets Paul Pratt recommended using Dow (which is Silicone based). I was intrigued by that.

I think that anywhere inside the GS3 - Dow or Superlube should be used. No Petroleum (I am saying this from - shamefully admit - experience).

LM should do a special deal on all the plastic boxes. The display/keyboard, the drain, and the brain. They all fall apart after a few years in the heat....

AssafL wrote:My guess is LM are recommending this due to lawyers.

Glad you said it.

AssafL wrote:Half of mine are glued back on using contact cement....

My coffee button was really dirty with coffee stains I couldn't remove (I should wipe my hands after distribution ) The new decals are expensive, but they make the machine look new.

AssafL wrote:Mine is okay - but I am careful with it. How does one replace that? Can it stretch over the group?

I don't know -- I haven't replaced it yet. Pretty sure it will stretch over the group if the plastic group cap, metal group cap and bayonete ring are removed.

AssafL wrote:Early designs had the needle fit too loosely over the pinion. After mine moved out of adjustment I disassembled it, adjusted it using a Fluke pressure transducer and secured it to the pinion using a drop of CA glue - Haven't lost accuracy since!

Most of us ordinary humans will just replace the gauge. Cost is pretty reasonable: $37 for the steam gauge and $44 for the brew gauge.