Bryce,
I am not familiar with the M20, but I am very familiar with the M31, which is newer. Does your machine have a printed circuit board in it somewhere? They're usually under a cover.

It sounds like your machine is trying to fill the boiler but the valves are not operating properly. If it's coming out the overpressure valve, which is back by the pump on mine, then either that valve is crudded up, not working, or there's a blockage somewhere else, like say a solenoid operated valve not opening.

You're going to have to check the solenoid operated valves for proper operation. You'll also need to check to make sure the appropriate ones are getting power. The boiler fill valve should be opening if your boiler isn't full. Chceck the transformer -- it's a large round object for mine. It should have output voltage specs. For me, it's 24V AC that operates the valves. So if that's the case you'd want to check for 24V AC at the boiler fill valve leads when it's trying to fill.

Thanks for the response. Ive taken apart the valve that the solenoid opens as a start point.

A small amount of rust but it was moving and not siezed.
This is where it screws in.

The centre hole was clear. I assume the hole to the left of centre is intended by design. Unscrewing the tube (leads back down to the water inlet valve) to the far left reveals a flow reducer.


The small hole appeared to be blocked, which I've cleared. If this was indeed blocked it means that water from the pump was being prevented from entering the valve pictured, and therefore not entering the boiler.
I'll reassemble and see what effect this has.

Reassembled and it seems that the blockage that was found was the problem. Now the pump engages and fills the boiler as intended. However the machine continues to fill the boiler and I turned it off when the sight glass was almost completely filled. Shouldn't the boiler stop filling once its half full? Im not sure how this machine automatically stops filling, as my other machine has a probe in the sight glass that would earth and this does not.
EDIT: I should mention that Im only turning the power to the 1 position and not the 2 position which doesnt give power to the boiler and I assume that this isnt also bypassing the automatic boiler fill/ cut-off.

On the M31 there is a probe that goes into the boiler. See this thread:
Water, Scaling and Descaling with HX machines?

Check to see if you have one of those. If it's scaled up, then it won't be able to detect the water level. It would have to be descaled using citric acid if that's the case.

EDIT: If you have significant scale on your boiler probe, it's likely that you have a lot of boiler scale as well and will want to descale your boiler before too long.

Earlier you said that the wire from the level regulator led to what looked like a fuse on the side of the boiler. If I were to guess, I would say that you have a magnetic level float. I've never seen one in person or fixed one, but scale on the float is certainly a possibility. Hopefully someone familiar with the intricacies of Cimbali engineering can give some help about its operation.

Jim

definitely no level probe on this machine.

And here's the bit that I thought was a fuse.

It looks like it uses a magnetic float level (from the diagram)
http://www.cafeparts.com/listCategories...goryID=118

That is definitely the magnetic level float. Given that the moving parts of any float are at the water line, it is probably pretty scaled up. But again, I've never seen this one in person.

I can see two avenues to try.

1. A complete descale of the boiler, with the water level raised above the normal waterline.
-or-
2. Take off the magnetic level from the boiler and inspect its operation, doing whatever necessary to restore it to function. As I look at the boiler diagram, it appears that the gasket for the magnetic level is the same as for the heating element, but no guarantees... it might be oddly sized and impossible to find.

The one thing I can say for sure is that I would hate to have to buy a new one.

Jim

I would suspect scale on the float part of the switch as well.

Find your Cimbali dealer and order new gaskets for the boiler. Looks like there are a couple in NZ. They aren't terribly expensive. Make sure you can get them before you take it apart.

To check the float, I would unplug the black wires from level sensor. Measure
the resistance across the mercury switch. Drain the tank. See the resistance.
manually fill the tank with the manual fill valve on the front bottom right of the unit.
Look to see if the resistance changes (one position should be shorted and the other open).
I think when you drain it the switch changed resistance at a lower level. That is how the
pump turns on at low level and then turns off at high, then stays off until low again.
If the switch works, it must be something else. I would think it is the switch. could be the
float has a leak inside. Never floats?


I have a cimbali m20. I am having trouble too. In my case my switch did not turn on the
pump, eventually the water level went too low and the heat blew up inside.
I have replaced the heater but need to figure out the wiring. I will post a separate question on that to keep
topics on track.

Measured the resistance across the switch and got no reading no matter what the water level was.
I took off the side of the boiler to take a look.


The float appears to float (I cant hear or feel in it). Ill clean the crud off it and see what difference this makes.