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No, you said you checked the switch (Part 3240123) earlier and it was functioning properly. Hence my follow-up post which ended with:
The "switch" is just the electrical switch (Part 3240123) that you tested. The "pressure switch" (Cimbali part number 1320538.) is the entire assembly.
By disconnecting the switch and with the boiler no longer heating you've eliminated the problem being in the circuitry between the switch and the boiler. So as per the quote above the problem has been narrowed down to being a blockage in the pipe connected to the pressure switch, a ruptured diaphragm, or a jammed piston in the pressure switch.
The problem is unlikely to be a blocked pipe but it's the easiest and cheapest one of the three to fix so that's what I'd check first. If it's clear then it'd be time to move onto taking the pressure switch apart to check the diaphragm and piston. I've never taken one apart before so I have no idea what kind of hidden springs or other surprises there may be inside so if you go that route tread carefully!
Java "Good luck and be safe!" phile
So I had time today, pulled apart the pressure switch assembly piece and checked the feed, there was a build up in the pipe and into the assembly was partially obstructed, appeared to be like a lime or scale buildup, white in color. I cleared this out and brushed it with a pipe cleaner. I tapped the assembly and with a light pressure it released. So I reassembled it and now it works! The pressure builds to just under mid-green so I think that's OK for the minute.
Many thanks and appreciation to Javaphile who kept me looking and finally finding the problem ?
If it doesn't heat up then the problem is with the pressure switch. The switch has tested good which leaves a blocked pipe going to the pressure switch or a shot diaphragm, or the piston that the diaphragm pushes up against the lever that pushes on the switch's button is jammed.
The "switch" is just the electrical switch (Part 3240123) that you tested. The "pressure switch" (Cimbali part number 1320538.) is the entire assembly.
By disconnecting the switch and with the boiler no longer heating you've eliminated the problem being in the circuitry between the switch and the boiler. So as per the quote above the problem has been narrowed down to being a blockage in the pipe connected to the pressure switch, a ruptured diaphragm, or a jammed piston in the pressure switch.
The problem is unlikely to be a blocked pipe but it's the easiest and cheapest one of the three to fix so that's what I'd check first. If it's clear then it'd be time to move onto taking the pressure switch apart to check the diaphragm and piston. I've never taken one apart before so I have no idea what kind of hidden springs or other surprises there may be inside so if you go that route tread carefully!
With-out pushing on anything on the pressure switch (With the machine unplugged of course!) is the resistance across the switch 0 or xxx? If the resistance is 0 then unplug one of the two wires from the switch (I assume there's only 2 wires connected to it.) and plug the machine back in and turn it on. Keeping your fingers and tools well away from the machine of course! Does it heat up? if so the problem is not with the pressure switch. If it doesn't heat up then the problem is with the pressure switch. The switch has tested good which leaves a blocked pipe going to the pressure switch or a shot diaphragm, or the piston that the diaphragm pushes up against the lever that pushes on the switch's button is jammed.
Java "Be safe!" phile
OK, checked this now and, when unplugged the machine does not heat up. So I guess it's the pressure switch. Perhaps just the part 3240123?
Last edited by cafecre; 15 August 2021, 07:47 PM.
Reason: image fix
With-out pushing on anything on the pressure switch (With the machine unplugged of course!) is the resistance across the switch 0 or xxx? If the resistance is 0 then unplug one of the two wires from the switch (I assume there's only 2 wires connected to it.) and plug the machine back in and turn it on. Keeping your fingers and tools well away from the machine of course! Does it heat up? if so the problem is not with the pressure switch. If it doesn't heat up then the problem is with the pressure switch. The switch has tested good which leaves a blocked pipe going to the pressure switch or a shot diaphragm, or the piston that the diaphragm pushes up against the lever that pushes on the switch's button is jammed.
It's easy enough to test the switch. With the wires disconnected from the switch move the lever arm manually so it pushes against and releases the red button in the above picture while measuring the continuity across the two terminals on the switch. If resistance goes from 0 too infinity and back as the lever arm pushes and relaxes against the button the switch is working.
Java "Aftermarket options may also exist" phile
Tested this today - had probes in the switch without taking the leads off but the resistance goes from 0 to xxx as I rock the switch.
The inside parts look new, even in the sub-drip-tray circuitry, most wiring is clean and very little residue on anything.
It appears to have had work done.
Under the drip tray, not seeing a contactor at all ... but I'm not all that up on electronics.
If so does the lever arm move as the boiler pressuriszes and trip the switch? If yes then the switch (Cimbali part number 3240123.) needs to be replaced. If not, then is there any water/steam coming out of the bottom/middle of the assembly? If no then the pipe to the switch is likely blocked. If yes then the diaphragm in the assembly is ruptured and needs to be replaced (If you can get a rebuild kit for it.) or the whole assembly needs to be replaced (Cimbali part number 1320538.)
It's easy enough to test the switch. With the wires disconnected from the switch move the lever arm manually so it pushes against and releases the red button in the above picture while measuring the continuity across the two terminals on the switch. If resistance goes from 0 too infinity and back as the lever arm pushes and relaxes against the button the switch is working.
The usual caveats about working around hot boilers and high voltage apply. Letting the machine cool down too room temp and unplugging it from power before taking the covers off apply.
Java "Aftermarket options may also exist" phile
Great response!
Cheers, so I had a look today finally, pressure switch looks just like that pic.
The lever arm doesn't move on its own at all when the pressure builds.
I can manually rock the arm and hear the switch (small red one) click.
There is no steam coming out of the middle of the assembly or anywhere there.
I'm guessing maybe a rebuild kit or just a whole new assembly, C 1320538.
The above assumes the pressure switch is the problem. It may not be. If it checks out (The switch opens and closes and the lever arm is being moved by the diaphragm as the pressure increases/decreases.) then the problem is most likely in the contactor which is probably located in a box below the drip tray. This thread discusses replacing the contactor in a La Cimbali machine and gives specs and alternative sources for buying one. Included in the thread are pics of what the contactor looks like.
If so does the lever arm move as the boiler pressuriszes and trip the switch? If yes then the switch (Cimbali part number 3240123.) needs to be replaced. If not, then is there any water/steam coming out of the bottom/middle of the assembly? If no then the pipe to the switch is likely blocked. If yes then the diaphragm in the assembly is ruptured and needs to be replaced (If you can get a rebuild kit for it.) or the whole assembly needs to be replaced (Cimbali part number 1320538.)
It's easy enough to test the switch. With the wires disconnected from the switch move the lever arm manually so it pushes against and releases the red button in the above picture while measuring the continuity across the two terminals on the switch. If resistance goes from 0 too infinity and back as the lever arm pushes and relaxes against the button the switch is working.
The usual caveats about working around hot boilers and high voltage apply. Letting the machine cool down too room temp and unplugging it from power before taking the covers off apply.
Hi all, I have a newly purchased (seconds) La Cimbali M21 Junior, looks quite clean inside, a few rust points around the screw heads.
I cleaned it up and tested it out, having only had a Breville Barista Express to date, this seems like a great machine.
I noted as the machine warmed up the pressure gauge kept climbing, well into the red so I switched it off.
I got a burst of steam from what I assume is the pressure relief valve on the top shortly after.
I found posts here that showed how to lower the boiler pressure with the nut and spring, but after winding that off to the outer limits of the thread I still have a dial going well into red.
My options are get a tech to look at it, which I think is what I will do.
Is there anything that I can check before then that might be worth doing before I haul it off to a service place?
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