A friend gave me his old Gaggia TE machine. It had been sitting idle in his garage for a year, but he claims it was in working condition when he stored it. I plumbed it into my waterline, normal household pressure, opened the valve, and turned it on. The boiler filled up quickly. Here's the problem. It just keeps filling and runs out the overflow line on the top of the boiler and then empties into the drain pan under the group head.

I was under the impression that this machine could be plumbed into a normal household waterline. True? And if so, what should I look at next?

Thanks.

Commercial espresso machines have an autofill circuit. If you open up the machine, you'll see a metal wand sticking into the boiler with a single wire coming off it. When the water touches this wand, it closes a circuit and shuts down the boiler refill. if the wand scales up, it gets electrically insulated and no longer works. Then the boiler refills forever.

Screw it out, and wipe off the scale and gunk. This is not guaranteed to work, but it is the likeliest culprit when a stored machine does this.

Did you put a regulator on the supply line? Your line pressure is probably way too high as well. It could also be a solenoid that is stuck open or a manual fill valve stuck open. Does the water flow when you turn on the water pressure? If it does not, when you turn on the machine do you hear the solenoid click and pump run?

I took the wand out and cleaned it just to be sure, but I think it's likely that my problem is from running it directly off house line pressure. What is the proper psi to have for the line in?

Best, Chris

I don't know for your particular espresso machine, but manufacturers' recommendations vary from 20 to 40 PSI. Since household water pressure is usually 55 PSI, a pressure regulator prior to the machine is required.

Okay. I finally plumbed the machine in with a 50 psi pressure regulator. But I'm still having the same problem with the autofill not turning off. I opened the cap on the boiler (it was full), siphoned off some of the water, and powered up. When I do this, the machine seems to work fine (although some steam was coming out of the overflow pipe that runs from the top of the the boiler down to the drainpan) until the water level gets down to the point where it needs to refill. Once it starts to refill, it just won't stop. Again, the refill circuit wand is clean.
So, two questions. 1) Any idea what to check next? 2) Does anyone know of a shop in the LA area (Inland Empire) where I might get it serviced? Thanks again for all the help.

Best, Chris

If the autofill starts but doesn't stop, it's almost certainly the brain box, a Gicar or Giemme labeled black box under the boiler with lots of wiring connections. Get the same unit from espresso parts or another supplier, and replace it lead by lead.

There is a possibility that there is a solenoid in the water line. If so, it's not sealing due to particles
or damage. Trace the water line to see if there is such a thing inside the machine.

If so, take it apart - mark which end is input and which is output, and clean it very, very, well. Flush the
house supply line that attaches to the solenoid before re-assembling.

Bob

Chris -

As a quickie - if you start to disassemble the boiler fill solenoid valve - MAKE SURE the water supply to the machine is SHUT OFF.

Also, make sure the wire leading from the level probe to the controller box has good contact on both ends.

Otherwise, here's what I would do:

Unplug the machine and gain access to the boiler.

Syphon out as much of the water as is reasonable - maybe leave the boiler 1/3 full. Whatever fitting on the top of the boiler you remove to enable this syphoning, keep it removed for the time being.

Disconnect one of the wires going to the heating element and tape over (this is a 120V machine?)

Disconnect the wire at the level probe but rig up a short section of wire into the female terminal you disconnected such that this wire (typically green) can be momentarily well grounded - i.e. to the boiler surface.

Ensure that the water supply valve to the machine is open.

Plug the machine in and turn it on. After a few seconds delay, you should hear the fill solenoid click open and the pump run. It is possible that this machine does boiler fill from line pressure alone (but not likely) - in this case, the pump would not run.

As the boiler is filling up, ground the short section of wire you rigged up. Does the pump stop?
Do you hear any sound from the fill solenoid?

If the pump continues to run and the boiler continues to fill, shut the machine off. If the pump stops but the boiler continues to fill, this points to a boiler fill valve that is sticky or leaking due to debris as BobS said. If the pump continues to run, this points to, unfortunately, a problem with the relay on the controller board as Jim Schulman suggested.

Well, I took apart the water line solenoid, cleaned and put it back. It seemed fine. But while doing this I also checked the wire from the level probe and found one contact that might have been loose. Fixed it, fired up the machine, and so far so good. Could the probe line have been causing the autofill to keep running? BTW, I believe the machine fills just from line pressure.

In any case, now I'm just working on getting the right grind. For which, thanks. Fingers crossed.