I potentially have an issue with my GS3 and I'm wondering if anyone here may have had the same issue or know what it is.

Yesterday, I made an Americano. First time since I can't remember when. When I pressed the hot water button it trickled out as if there were some blockage. After 4-5 presses it dispensed the right quantity. Then today I was making a cappuccino and the steam wand didn't work. There was pressure in the boiler but no steam. Then around 10 sec later some steam escaped on its own. I tried again and after a few seconds I could steam again as normal. Again suggesting some form of blockage.

Has anyone experienced something similar or know what the issue might be?

I haven't seen those symptoms on my machine and haven't read any posts here like yours.

It's strange because hot water and steam use two different paths with two different kind of valves. One thought is that some debris got into your steam boiler and temporarily obstructed both valves, becoming dislodged after you worked the valves a few times. I can see that happening with the hot water solenoid valve because it takes water from the bottom of the boiler, but it's hard to see how it could happen to the steam valve because it takes steam, not water, from the top of the boiler. Seems to me that could only happen if your boiler is overfilled, but you would see water and/or very wet steam from the wand in that case.

If contamination is the explanation, the source could be a carbon filter that wasn't properly flushed or has broken due to excessive pressure, or lack of a sediment filter before the machine. What's your filtration/softening setup, if any?

Another source of contamination can be the copper pipes feeding the two valves. Depending on the water composition, very fine bits of oxidized copper can come loose and buildup in the valve (or get into your cup). I've never seen that happen with the tea water solenoid valve but have seen it happen with steam valve, presumably because the steam is at a somewhat higher temperature than the hot water. LM replaced the copper tubes in the steam path with plated tubes to deal with that, and if your machine doesn't have them you can get replacements that aren't terribly expensive and are relatively easy to install.

The only other scenario I can think of is that the steam boiler pressure gauge is blocked or stuck (i.e., is giving you a misleading reading) and the boiler temperature is lower than you think. That could be due to a bad steam boiler SSR or a problem on the logic board possibly caused by a leak that's allowed water to seep into the brain box. Seems unlikely that the gauge and board could fail at the same time, but it's possible. In an abundance of caution I would remove the side panels and carefully inspect inside the machine for any signs of leaks (condensation, drops of water, mineral deposits on the chassis floor, etc.) Always good to do an inspection like that periodically anyway.

If it happens again, I'd shut down the machine, unplug it, let it cool off, then drain the steam boiler. Look for any sign of debris or contamination. Then remove and disassemble the tea water solenoid and steam valves and look for signs of contamination. There's a steam valve rebuild kit that you might want to install if it's been a long time since you rebuilt yours or if it hasn't been rebuilt. Sometimes they go for very long periods of time without needing a rebuild, sometimes they need rebuilding more frequently, perhaps depending on water composition and/or whether you have the copper or plated tubes.

Hi Peppersass, thank you for a detailed response (again ). Thankfully, it has been ok this past day or two. I will keep a close eye on it and if necessary call out the local engineer who is qualified to service LM machines.

I have no filtration/ softening of the water I use. I've been informed the local water is soft enough and any local roaster/ cafe I've asked about this say the same and say they haven't had issues with mineral build up. I've also checked for leaks and there doesn't appear to be any to my eye. Nor any noticeable mineral build up.

I have never rebuilt the steam valve but I may look into. I purchased my machine from a roaster who had it serviced regularly but that is almost two years ago now. It's a 2014 model so not sure if it has the copper or plated tubes.

Thanks again, fingers crossed it was a one off thing but I'll make sure to check things regularly.