Nuova Simonelli Premier Restoration Part 2

The hydraulic line was generally intact and without evidence of any prior leaks. However, it was the sight glass assembly that captured my attention, even when I first inspected this machine. The sight glass displays how much water is in the boiler. This is especially important because it can diagnose many problems if the water is not around the middle of the gauge. If the gauge is full of water there will be no room inside the boiler to make adequate steam, and the water level probe needs attention. If there is no water in the sight-glass, unless the lower pipe is blocked, there is no water in the boiler. Running a boiler element dry could lead to the heating element failing and the machine itself to implode from its own expanding gravitational pull. This picture is the fitting to the boiler that the lower sight glass pipe connects with the sight glass assembly.
Maybe some readers will look at this mysterious crud without much of a nod, but I kid you not it gave me nightmares. Specifically, I was scared that the inside of the boiler was coated in such a crust, also that the hours of chipping and soaking in acid would eventually dissolve both this substance and the magical cure for cancer contained inside it. The lower sight glass pipe accompanied the machine, unattached. I believe it was initially removed to drain the boiler before the whole thing was discarded. It would be just another part to be cleaned and inspected for damage. I would not be able to feed water into this machine until this was repaired.

Another part that would no doubt need replacing is the dual pressure gauge. The gauge has two inputs in the back, one on top and the other below. The top gauge connects to the top of the boiler and registers how much pressure is in the boiler. This is quite useful because steam pressure also reflects the internal temperature. While other methods are much more accurate, boiler pressure will also give a temperature guess for the brew water. The steam pressure gauge will also express when the pressure is sufficient to use the steam wand or hot water spigot. As can be seen, the green space starts at 1 and the red starts at 1.5 which is common to all espresso machines I have ever worked with. The bottom gauge is attached to the water main just after the pump and reads the water pressure. The green zone is between 5 and 10 bars of pressure. Typically, the water pressure feeding the machine is under 5 bars and the pump will bring that pressure up to around 9 bars during the brewing process. As you can see, the water pressure gauge is stuck at approximately 18 bar. Maybe if I throw it against a wall it will work again, probably not though. As they cost around $100 it will be a part I replace once I decide to either sell the machine or put it into production. However, just reading a post on lethargic pressure gauges, I might just soak it in acid and see if anything changes.

Disassembling the hydraulic lines was swift and generally unphotographed, sigh. I think my general sorrow of the upkeep and my fear of running out of latex gloves before everything found its way into the acid. Taking off the drain cup and expansion valve were quick to remove as was the boiler-fill electro-valve and hot water spigot valve. Starting in that order, the drain cup is where all the extra and dirty water pools before draining out of the machine. The expansion valve does just as its name implies, gives the water in the hydraulic system space to expand as it heats. The electro-valve lets water pass through the valve by electric command of the control board. The black box is fastened around a hollow cylinder that contains a magnetically controlled plunger. I was much more hesitant taking it apart than putting it back together. It is quite a simple yet effective device. The valve for the hot water spigot did not want to release its design secrets as willingly. Other than the handle, not one part of it was willing to unfasten to my herculean efforts. Since the valve seems to move fluidly I am not too afraid of it being clogged. I will test it out once everything is put back together to see if it leaks. After that it was just carefully removing all the copper lines. Hoping that part diagrams and a logical understanding of the system, only one picture was taken. Oh goodness, I hope this will not be a mistake.