Randy,

Thanks for the tips on the parts of the group head. So I guess you would recommend cleaning out the screen and the Gicleur? I spoke to Wendy at Salvatore today and she recommended disassembly of the lower group and soaking the piston to remove any oils or other contaminants that may be blocking it. I will probably do both to make sure I have all bases covered. I am kind of surprised that it seemed to happen all of a sudden as I had a couple cups yesterday without issue.

Should these threads be dressed with plumbers tape on reassembly?

Bill

Bill,

I posted a reply earlier that seems to have been lost in the ether. I'm glad Randy has stepped in, as I'm no expert, just mechanically inclined. (Some might argue for mechanically willing and drop "inclined").

My first thought is I'd want to verify that the pump is working. Does the pump come on when you press the brew button? It's possible that you got steam from the boiler with water remaining, but the pump is not operating, thus the lack of water in the group head. I'm guessing you have the hot water tap on the right like mine. If you open it, you should get hot water and the boiler will drain, causing the pump to come on to refill the boiler. The pump sound is pretty obvious. No pump sound after pressing the brew button, lack of water from the hot water tap or the boiler not refilling would indicate a pump issue. If the pump is not operating at all, I'd be careful about letting the boiler heat up without water inside. There is a switch inside my machine at the top towards the rear that (If I remember correctly) turns the heater off but allows the pump to run.

If the pump is operating, you could go a bit further to test the output. Since water is not coming out of the group head, you could undo the output side of the pump, turn it on and verify flow. I'm not sure how to easily test the flow rate when the pump is not under pressure. The usual way is to put a measuring cup beneath the group head (no portafilter), run the pump for 10 seconds and measure the quantity. If you get 2.5 oz or more, the pump is good. 1.5 oz or less, the pump is bad. In between, the pump is marginal.

If you are confident the pump is working OK, then the group head would be the next likely culprit. Since it happened suddenly, I might try to diagnose the 3-way valve operation (operated by a solenoid on the lower group head). Otherwise I'd be diving into the group head to look for scale buildup.

Randy's link is spectacular. Wish I had it back when I started the project. Our group head is slightly different, but you should be able to work things out pretty easily from his info and your observations.

Our mushroom is a little challenging to get at. You will likely appreciate having new washers when you are doing the job. I was really careful, but I still found the old washers were not really useable after the disassembly. My initial attempts to reuse them couldn't get past the leaks.

You haven't mentioned your backflushing habits. If you try the machine and manage to get water out of the group head, you could try backflushing a few times to see if things improve. If they do, that would indicate a need for more thorough cleaning / descaling.

I used teflon tape on the mushroom and a couple of other spots. I didn't use it everywhere. Most of the copper tubing didn't have it / doesn't need it.

Good Luck!

Steve

@Randy, thanks for the tip on the red wire. I relocated it slightly when I reassembled, but it showed no wear after nearly 10 years in that location. I think the picture makes it look worse than it is. Thanks also for the link to your excellent write up. I'm sure I will make more use of it in the future!

Steve,

Thanks for the advice, I am much like you and am a shade tree mechanic. Here are my answers to your questions.

I usually backflush every week with Joe Glo as per Salvatore's instructions with the blank. As far as I can tell the pump(without disconnecting it) is pumping and sounds as it should, but does not put out the right amount of flow. THe water flow out of the hot water tap is the same as it was before the blockage.

I was on the phone for about an hour with Wendy from Salvatore's shop and she also thought the 3 way valve could be the issue. She gave me instructions on disassembly but I have been unable to remove the piston from the nut on the top. I removed the entire valve assembly but that top nut that holds the piston to the brass piece I have been unable to separate (see pic).

Furthermore I removed the mushroom cap and the gicleur from the group head and descaled the pieces in a mixture of 1.5 liters water to 1TBsp of citric acid at 190 degrees. Unfortunately the chrome on the gicleur flaked off on the lower portion not the nut. Do I have to replace this or can I use it with the copper finish only? Should this have happened in 10 minutes of soaking?

Eric,

Thanks for the advice. Just wondering why do they chrome the piece if it the coating will come off when you descale it? The nut portion above where the coating came off did not lose any of the coating. Not sure why the lower portion did.

Bill

Eric,

I can not seem to separate the two pieces even after heating. Maybe if I cool the steel then heat it the parts will separate. I can't imagine there is much more than 3 or 4 threads holding the two together. I wonder if the dissimilar metals have fused together?