I after having my GS3 turned off while on vacation, I've been having some trouble with it. I can't seem to get the time of the extraction (with or without coffee in the filter) to go below 40-45 seconds. The pressure gauge shows 9 bar, but it sure doesn't seem like the water coming out of the group head has any pressure left. Has anyone had same problems, and does anyone know how to fix this? My best bid is that something is blocking the lines somewhere after the pressure gauge. Maybe someone has a good idea/ tip for cleaning/flushing the system? Help will be greatly appreciated

Since the panel gauge on the GS/3 shows the pressure at the coffee boiler, it's certainly possible that there is a partial blockage downstream toward or in the grouphead that prevents the correct pressure from reaching the dispersion screen. It is easy to imagine some minerals precipitating out during its vacation, or a bit of scale getting into the gicleur for example.

That said, the flow at the screen never looks powerful - water just dribbles out (though with about 8 1/2 bar of persistence!) and just looking, one doesn't easily imagine the power behind it.

One thing to try that would eliminate your coffees and baskets from the variables: try using the back-flush disk and try the portafilter wiggle to compare how the pressure seems compared to its prior behavior. If there seems to be lots of pressure, it is not necessarily conclusive since it will be tough to discern five bars from nine (both act plenty strong) but at least if the pressure seems very weak, your concerns will be confirmed. Or you could get lucky and that back-flush process might loosen something up - who knows.

Again, chances are that the problem is just a blockage addressable by disassembly and cleaning. Depending on the age of your machine, you may want to get a gasket replacement set before you start (that is, if you feel qualified to do this job yourself - and on this one DO think twice about that adventure; getting to gicleur level has brought some DIY-ers into serious problems).

I don't recall any rumors of pump failure problems with the GS/3s, but there was a history of clogging with some of the earlier production (famously the ones that had sat in a warehouse a long time and became known as the "fire sale" units). Hopefully, Dick Green and some others on this forum will chime in with timely advice and some additional and better diagnostic ideas.

The gicleur blockage that I and others experienced affected the flow rate but not the brew pressure. As long as the water path isn't completely blocked, the pressure at the group head after the path has filled with water should be the pressure to which the pump is set, within about 1 BAR (i.e., when using a blind basket.) However, if the gicleur is partially blocked you may see longer brew times because the flow rate is slower.

Your statement that the shot time is running 40-45 seconds with or without coffee (presumably to get a certain volume of liquid in the cup) suggests that the flow rate is too slow.

The first thing I would do is measure the flow rate. This is simple and easy to do. Remove the PF and basket, and put an accurate measuring cup under the group head. Hit the brew button and let the water run for the maximum shot time, which is 50 seconds. When the shot is over, divide the milliliters of water in the vessel by 50, then multiply by 60. This will give you the flow rate in milliliters/minute.

The unrestricted flow rate can vary a bit from one machine to another, but it should be in the range of 300ml-500ml per minute. Mine typically runs right in the middle of that range, around 400 ml/min. If you run the test repeatedly, the flow rate should be relatively consistent. When I was experiencing the gicleur blockage problem, the flow rate after backflushing would decrease quite a bit, starting at the high end of the range and gradually dropping to or below the low end and staying there. This suggested that the debris got moved out of the way during the backflush, but eventually came back into position to partially block the gicleur. Maybe it was a flap of debris or a pocket of heavy material "swimming" inside the gicleur. Others experienced a permanent drop in flow rate into the 200 ml/sec range and below, suggesting something immovable was blocking the gicleur.

But as Anvan said, all of the GS3s that exhibited this behavior were the infamous "fire sale" machines sold in the 2009 time frame. We've never had a report of earlier or later models with this problem. That said, it's possible some debris or scale has lodged in your gicleur. I would do a complete detergent backflush and check the flow rate again. If there is a blockage, and you're lucky, the backflush might dislodge it.

Anvan is correct that it's not easy to get to the gicleur to clean or replace it. You have to drain the brew boiler, open the group head, remove the solenoid valve and pull the TL-30 tube out. It's a bit of a chore, requires the right tools and you have to be quite careful, especially if you have to unscrew the gicleur to replace it. If you have a dealer with local service that would be the safest way to get the problem corrected.

FWIW, if your machine is plumbed in you should use a 1-micron filter before the machine to trap any debris from your water supply or filter system (if you have one.) A typical softening system will have a 1-micron filter before the softener and a properly pre-flushed carbon filter after the softener (pre-flushing gets rid of small particles of carbon that can come off a new filter.) Even if you are running from the reservoir, you should take care to ensure that no debris enters the water path.

FYI - I also noticed a gradual drop in portafilter water-flow in my GS/3 over a period of one year, even with weekly back-flushing. Checking part# A.5.003 SHAFT FOR PADDLE, I found when looking from the bottom of the shaft that there was some brown residue within the hole. Using a stylette about the size of the cross-drilled holes, I reamed-out the bottom hole and the cross-drilled holes. There was a BIG difference in the amount of air that I could blow through the bottom hole. The water flow-rate is back from about 3 ounces per minute with the portafilter to a better 5+ ounces per minute.

In the event that you find a similar reduction in flow, this may be worth trying.

The water flow-rate is back from about 3 ounces per minute with the portafilter to a better 5+ ounces per minute.

If that is not a typo of sorts, that is still an unusally low flow rate. Something like 500 ml/minute (~17 ounces per minute) with or w/o PF is reasonable.

EricS:
5 ounces/minute equates to about 150ml/minute. Any suggestions as to what I should check to raise that figure?
The Gigleur is new, as are the O-rings. Brew pressure is 10 Bar. Max brew pressure is 12 Bar. Plumbed-in tap water pressure is 4 Bar.
Marshal

Forgot to mention: I have a paddle machine.
Marshal

Marshal -

Yes, I knew you had a paddle machine from your post but thanks, anyway.

Now, I am being nitpicking but I would adjust the inlet pressure to the machine to about 2.5 bar under flow conditions. With the paddle "full on" and an empty portafilter, the group pressure gage should register 8.5 to 9.0 bar and the brew boiler gage should read a couple of tenths higher - MAYBE 0.50 bar higher.

The maximum pressure you mentioned - 12.0 bar - you should never see that during an actual brew cycle. The brew boiler pressure may hit 12.0 bar during machine warmup but the thermal expansion valve will relieve by drip . . . drip . . . drip into the drip tray to not allow that pressure to go above 12.0 bar.

But, to your "problem" - the only thing that comes to mind that would cause that low of a flow with the pressures you reported would be a clogged dispersion screw or a severly clogged dispersion screen. Have you serviced these lately? LM machines are spectacularly easy in this areana.

Eric: thanks for the reply. I'll have another look at things to see where a blockage might be.
I back flushed the system again this morning, cleaning the new screen and new screw in a separate container. I noticed that the water/detergent flow was inconsistent in emptying into the drain box; sometimes more, sometimes less. Does that suggest to you some sort of moving blockage in the line?
I see no more than 10 Bar when brewing and never exceed 12 Bar at any time. I'll back off the brew pressure to the original 9 Bar. In order to get the water line-pressure down to 2.5 Bar, I'll need to buy some sort of line-pressure regulator. Any thoughts as to a vendor or a model?

TIA,
Marshal

Any thoughts as to a vendor or a model?

Yes, but let us ALL solve the real problem first. Consider the 2.5 vice 4.0 "icing on the cake" .

You SHOULD know the quality of water the machine is being fed and treat it accordingly including pressure regulation and filtration . . . but that can be step 2 and there exists "upmteen" posts on HB as regards those parameters.