Hello everyone. This is my first post on this forum but I have found it to be very useful for DIY fixes.

So last night with my machine off I heard an unusual noise and had water all under my machine. The rubber chimney on the vacuum breaker was completely full of water. It is plumbed in but not out. The electronics were haywire. I unplugged it and disconnected water. Initially the machine would not restart without blowing a fuse. I opened up the housing for the motherboard and saw nothing that looked fried. After work today it seemed to start up fine with normal LED display but I haven't let it run for long.

I removed brass head on what i think is the steam boiler drain and not much water came out but I can still hear some water inside. There are beads of water next to both triangular plates on each side of boiler and more will form if I tilt the machine.

So it seems to me that maybe both O-rings have gone bad and maybe water dripped into motherboard allowing the steam boiler to overfill. I am not sure if this makes any sense since this occurred when the machine was off.

I know one problem from another member was a failed check valve for the hot water/tea dispenser with water flowing backwards into the steam boiler. It seems like it is that or a stuck solenoid. Is there a simple way to determine what is causing the overflow problem?

Any help or ideas would be greatly appreciated. Thanks

Vince

Do Not Turn On Your Machine Until You Fix the Problem!

If you do, you risk permanent damage to the logic board, which is quite expensive to replace.

Your steam boiler overfilled. That's a common symptom when water contaminates the logic board. Water on the logic board also explains "haywire" behavior.

The cause of the water contamination appears to be leaking steam boiler seals. I suggest you search the forum for posts about leaking GS/3 steam boiler seals. I posted photos of my experience replacing the seals, and there have been a couple of recent posts from other forum members who had to do it.

I think the sequence may have been:

1. Water leaking from steam boiler seals finds its way into the brain box and contaminates the logic board
2. The contaminated logic board fails to see the "full" signal from the steam boiler level probe and overfills the boiler
3. Water spews out of the vacuum breaker, possibly causing more water to get to the logic board, until the water pressure closes the valve. The rubber chimney remains full of water.
4. The steam boiler OPV (over-pressure valve) probably triggered too, relieving the over pressure by venting into the drain box. You might not have noticed this.
5. The contaminated logic board goes "haywire".

You may have gotten lucky -- there may be only minor contamination to the logic board and it may have dried off. But it's too risky to just power up the machine. If the board is still contaminated, a component could short. They don't fix components on these boards. The board has to be replaced and it costs hundreds of dollars (don't ask how I know!)

The following are recommendations for repair. If you are comfortable with electronic and/or mechanical work, you can do the repairs yourself, like I and other forum members have done. If not, you should contact a nearby La Marzocco dealer or qualified service technician.

Remove the logic board, noting where all wires connect -- take a photo. Wipe up any water you see on the board. If you see any signs of mineral deposits, you can remove them with an evaporative circuit cleaner or isopropol alcohol. Although some dispute the effectiveness, it won't hurt to put the board in a bag of raw white rice overnight. That may further dry the board. If you have or can obtain some crystal dessicant that would be even better.

Next, you'll have to replace the steam boiler seals.If you think you can do the replacement, contact La Marzocco USA directly. They'll sell you the parts you need and answer any questions. Hopefully my photos will help.

Finally, there's a newer version of the vacuum breaker with a plastic tube that goes to the drain box. This will prevent steam escaping from the valve during warmup from condensing inside the machine and will also direct any water from an overfill to the drain box. The tube connects with a tee adapter to the tube that leads from the OPV to the drain box. I've documented the upgrade process with photos on a post you can find by searching this forum. It's not hard to do. You can have the dealer or service tech do the upgrade, or you can get an upgrade kit from La Marzocco USA and do it yourself. It's not hard to do if you're comfortable with that sort of thing.

The rubber chimney on your vacuum breaker indicates that it's a somewhat older GS/3. What is the serial number of your machine? It's embossed on a metal plate on the left bottom chassis rail, just below the left side panel. I ask because all of the steam boiler seal failures of which I'm aware have been with a problematic lot of GS/3s known as the "fire sale" machines. They have serial numbers in the 500-700 range. No one knows why these machines have had so many problems. It's possible they were damaged by sitting full of water in a distributor's warehouse for over a year. Or, there might have been a serious manufacturing and/or QA lapse at the factory for a short time six or seven years ago.

All I can tell you is that there are thousands of GS/3s out there, and this problem seems to affect only a very, very small number of them. And, after replacing the steam boiler seals on my GS/3, I've experienced no further leaks. I've not heard about any leaks from other forum members who replaced the seals.

Thank you for your reply. Of course I fall into the serial number range you mention at SN#604.

Removing the brain box sure looks like a pain. I guess air drying and using a blow dryer is not recommended.

I have done a few things on this machine. I had a leak from the 90 degree elbow joint at the bottom of the steam valve and then had to replace the steam valve with the rebuild kit. I suppose the steam boiler seals are no harder than that. Can the heat exchange side and heating element side can be worked out around the frame? Did you have to remove the temperature probe and wires connected to the heating element side?

Does it make sense that water is still oozing around the seals even though the water line is disconnected? I reconnected the water line just to see what would happen and I don't think it filled the steam boiler or made the leak worse. No other leaks were spotted. Right now everything is disconnected and the brain box is pulled out away from the water leak.

Vince

shallow sand wrote:Thank you for your reply. Of course I fall into the serial number range you mention at SN#604.

I'm sorry to hear that for your sake, but it's undoubtedly a relief to GS/3 owners who don't have machines in the dreaded fire sale range. So far, all of the reports of steam boiler seal failures are from owners of fire sale machines.

shallow sand wrote:Removing the brain box sure looks like a pain. I guess air drying and using a blow dryer is not recommended.

If you mean just opening the box, letting the board dry and hitting it with a blow dryer, the danger is that you won't be able to remove any obvious mineral deposits from the underside of the board. If there's a lot of water under the board, the blow drying might not be able to make it all evaporate. Also, I don't like using hair dryers because it's too easy to overheat the board.

But If you're not comfortable removing the logic board, you can try the air-dry/hair-dryer approach at your own risk. Try to sop up any water you see under the board and hold the hair dryer well away from the board. Don't let it get too hot to touch comfortably. After fixing the steam boiler seals, switch on the machine and be prepared to switch it off immediately if you see anything unusual like continuous autofill, weird stuff on the display, etc.

Alternatively, it's not that hard to remove the board. The most of the wires attached to the large green terminal block, which you can simply pull off. Just be sure to take a photo before removing the other wires and mark them so you know where to reattach them. That said, I don't want to encourage you to remove the board if you don't have the experience and comfort level to do so.

Of course, be sure to unplug the machine before doing anything inside the brain box, even if it's just removing the cover. There's 120VAC voltage in there.

shallow sand wrote:Can the heat exchange side and heating element side can be worked out around the frame? Did you have to remove the temperature probe and wires connected to the heating element side?

Please click here to read my post and see the photos of replacing the steam boiler seals. The heating element can be removed without disconnecting the heater wires. I unscrewed the temperature probe connector to get the large spool of wire out of way so it wouldn't get damaged. It was not necessary to remove the temperature probe from the boiler. Otherwise, there are no other obstructions preventing the heating element from sliding straight out of the steam boiler after you remove the nuts holding the triangle plate in place.

The heat exchanger is another story. You'll have to remove some tubes, including both heat exchanger tubes, before taking it out. This is shown in my post. Be very careful when working the heat exchanger out of the steam boiler. There is a significant danger of breaking it -- another owner I know did so and had to replace it. Don't force it and don't try to bend the tubing.

BTW, you will need to drain the steam boiler before attempting to replace the seals. I forgot to mention something about your previous post. You said you removed the brass cap from the steam boiler drain, but no water came out. That's normal. It's a ball valve. There's a black plastic paddle to the right of the fitting that you have to turn to open the valve. Before doing that, make sure you have a tube connected to the fitting to direct the water into a sink or container, or position the machine over the edge of the counter and put a container under it to catch the water.

shallow sand wrote:Does it make sense that water is still oozing around the seals even though the water line is disconnected?

Yes. as long as the water level is above any portion of the failed seal, it will leak. If you didn't drain the steam boiler, then the water level is well above the seals and there's enough water weight to keep a steady leak going, depending on how far gone the seals are.

shallow sand wrote:I reconnected the water line just to see what would happen and I don't think it filled the steam boiler or made the leak worse.

Normally, reconnecting the water line won't cause any more water to flow into the boiler as long as the machines is off -- unless there's an obstruction in the steam boiler autofill solenoid valve. As I said, I don't think that's causing the overfill problem on your machine, unlike the other overfilling GS/3 that's recently been reported.

It could be water in the electronics triggering the autofill solenoid.

It could also be the lone checkvalve stuck open allowing cold water from the hot water mixer to flow through the hot water output into the boiler. Since mains water (in my case) was 3-4 bar, it was above the 1.5 in the boiler, triggered the OPV and blew an old Viton gasket in my HX tube. The reason the heater side did not blow a gasket was because I replaced it when switching from 110V to 220V.

(BTW - After replacing the check valve, I added a second checkvalve on that line - it was added to the GS/3 a few batches later)

Check the check valves. My machine is serial 602, so we might have similar failures.

Thanks so much for the replies. I went all in and order parts from La Marzocco to get my machine up to speed. 3 O rings, plan to go ahead and replace the coffee boiler O ring as well. upgrading the line from the steam boiler to the mixing unit for the tea dispenser with the newer double check valve assembly. replacing the vacuum breaker with the T connector into the OPV tubing, and replacing plunger in the solenoid valve for the steam boiler intake.

I don't think I have a big water issue in the brain box at least not that I could see but I think I will remove wires and inspect in closer it closer to be safe.

Parts should arrive on Monday but I will be out of town until Sat Feb 21st, so Sunday will be the big day.

i have recently replaced the elbow joint from the bottom of the steam valve ~$50 and installed the steam valve rebuild for ~$50. Now another $200 of parts.

Hopefully all goes well

shallow sand wrote:I have recently replaced the elbow joint from the bottom of the steam valve ~$50 and installed the steam valve rebuild for ~$50. Now another $200 of parts.

We home baristas get off easy! Be glad you're not into old British cars or musical instruments or high end audio or Pateks - fresh matched sets of serious tubes annually or routine maintenance on a high end watch will buy a nice HX or DB machine.........every 5 years.

Enjoy that LM - it's a wonderful thing.

Update. I finally had a chance to replace the seals on the steam boiler. I also installed the double check valve system in the copper pipe going from the steam boiler to the mixing valve. No leaks from anything that fills just from line pressure, but when i tried to turn machine on all I get is a blue light on display. The La Marzocco GS3 does not display and nothing works. I removed the motherboard and cleaned it with isopropyl alcohol but the same thing happened when I tried to restart it. There was no obvious corrosion but I assume from reading other threads that it must be a fried motherboard. I assume it isn't worth sending it somewhere for retesting? Before buying a new one.

Also, I ordered the new vacuum breaker that connects with tubing to the OPV tubing, but the elbow joint they sent is too long to fit(the copper tube welded to the fitting). At Peppersass's helpful suggestion, I could attach the fitting by removing the screw holding the back frame in place but even when the nut was fully tight, the frame could not be reattached and was pushed out. So I have reinstalled the old vacuum breaker. It seems like the copper pipe part of the joint is too long. Has anybody else experienced this problem? I will call La Marzocco in the am and see if there is variability in this part.

Any advice on getting a discount from La Marzocco on the motherboard? Can Chris Coffee help with this. My unit is from 2009, but it seems like such a design flaw that La Marzocco would help out.

Vince

FINAL UPDATE

I ordered the new motherboard and installed it and everything is working again. Finally. I had to file down the side bracket to install the new vacuum breaker but it is in and now venting fluid into the drain box until the valve closes.

So everything back to normal. No leaks. Espresso tastes great.

Thanks to everyone who gave advice and gave me the encouragement to do it myself. I am definitely a more informed user now. A special thumbs up to Peppersass for his detailed descriptions and photos of these upgrades.

I guess the best news of all is I found this forum and now make better espresso than I ever have before. All my friends think I have lost my mind. What the hell do they know?

Vince