Hi there, I was visiting a friend the other day and I mentioned I was having trouble with an ebay coffee machine purchase and he said...I have a machine down in the garage, been there years. Well my ears picked up and we went and dug it out and it was like American pickers..."it's in here somewhere". Finally spotted it, and sure enough it was covered in dust and spiders webs. I got it home and did some research and it seems to be an early Bezzera BZ40.
I got it stripped down and clean it out, hooked it all up and was not a good start...it kept tripping my safety cutout. So after much checking here and there I got it running this morning. The heater working, water from the tap, steam from the arm....but no water from the head. The pressure went up to 1 bar, then it started cutting out again...the relay trips.
Just looking for any pointers, I'm fairly sparky minded as I build valve amps.

Cheers

Don

Pump could be shot, group solenoid could be clogged or broken. OPV valve could be stuck or broken, and even scale could be completely blocking the group feed lines. If its volumetric, Flowmeter could be clogged. The HX tube could even be ruptured and instead of feeding the group, is just dumping water off into the boiler. If the machine had water in it at any time when it was stored, and it froze, this would be my first thing to check(any anything else for freeze damage)

Did you hook it up to a pressured water line, or stick the feed line into a bucket? Lots of machines need to have positive pressure being pushed to them to work. Not all machines require this, semi-commercial machines almost always can use a bucket for feed, but often times commercial machines must have positive pressure to brew.

If the machine wasn't properly drained before storage, scale is likely a major concern, but probably can be remidied by a break down and a thorough citric acid descale of all parts. And also, even if scale wasn't an issue but water was in the boiler, you're gonna want to clean that out before you use it..

Yup was connected to the mains water supply, pump was working with clear water coming through. After getting some activity, it's now cutting out after 2 secs of turning on. I have changed the mains lead, disconnected the heater again, still does it. If the control circuit is not suss (expensive bit) I guess a strip down is definitely in order.

What do you mean by "cutting out"?
Circuit breaker?
Overtemp cutoff?
GFCI?
Just inexplicably shuts off?

When I flick the on switch, the relay engages then trips off again and also the circuit breaker in the wall socket cuts out.

Yipppeee, I got a coffee out of it finally. Well it's not perfect yet and I did nothing dramatic to fix it, it sure is a temperamental machine. All I did was check the heater, filled the tank...this could be what clinched it? Checked the relay (8ohms across the winding terminals...that seemed within spec). Put it back in and I thought why not leave of the pressurestat terminals (these were initially overheating and carrying on at the very beginning when I first turned on the machine) to see if the pump will run.....it did. Also water came out of the head....finally!! So kept checking and letting it run for longer periods....I plugged in the other terminals at the relay and was expecting the ol cut out....nope stayed on...and the heater was up and away. Let it get to 1bar....1.2...1.3.....1.5bar...click turned off, pressurestat works. Ran the pump and the only little prob is water is constantly flowing from out of the top of the 3-way valve into the tray. So tomorrow I'll check that, hopefully it's not the solenoid.
Anyway I managed to squeeze a couple of cups before dark....I'm doing this outside. Oh yeah, the steam wand is terrible, it's a little tiny thing....plenty of pressure....just not doing the stretch and roll very nicely. Oh well, I can worry about that later.

Thanks for the helps

Don

You were running the machine without water in it?!!?

Budget a new heating element. You'll be lucky if you don't need one.

(Edit - water will remove the heat from the element and keep it cool enough to keep from melting. Run an espresso machine heater without water and it WILL destroy itself or at least get severely damaged, leading to shorts, sometimes shorting to ground, which will trip the GFCI)

Also, the tripping breaker in the outlet is a GFCI - it is a safety device to prevent conditions that could lead to electric shock (as opposed to circuit breakers that prevent conditions that could lead to a fire). If you switched outlets and it now works, it is likely unsafe.

Well, there was always water in the boiler, at what level I can't be sure. It certainly wasn't full when I took out the element (which had no scale and tested fine) but there was hot water coming from the tap.....but not the head at the time. I had a powersurge protector in the power outlet because of the exposed wiring conditions, once the machine started running it was cutting out when I was switching OFF the pump.