More adventures with complicated superautomatics

[Gogar]

So, my Nuova Simonelli Microbar has two boilers, each about the size of a soda can. The heating element went out on the 'steam' boiler, and needs to be replaced.

There's two boilers, one for hot water and one for steam. Both very similar, except the steam boiler has a level probe that only fills it halfway so there's room to create the 'steam.'

Steam boiler:



New heating element, $30, you crack open the boiler and install in the bottom. PITA, but not 'difficult', per se.




Okay, let's get that bad boy out of there and crack it open. Ready?









Ooooh. I knew it would have some scaley-goo on it, but that's kinda gross.









Jeezus! There's about an inch of clay-like scaly disgusting gray MUD in the bottom of the boiler. NASTY.





The heating element is completely rusted through and fell apart upon removal. I can't believe it worked for that long and was SOOOOOO nasty.





Lesson? Use FILTERED water, and descale that machine about twice as much as it suggests.

That said, this machine had a long, 24/7 life in an airport pilot's lounge before I got it, and I can't imagine it got maintained very well.

I think i'm gonna crack open the coffee boiler just to make sure. Totally creeped out.

[Rikao4]

upside..
most of the kooties your drinking are dead..
well..
most of them anyway..
the other's have adapted...

Rika

[Gogar]

Done, ready to go back in!

[MRM]

That's just the mineral deposit left from boiling hard water. Nothing to be worried about. If there was soft water running through it all the time it would be clean as a whistle but it wouldn't taste as good. That's basically limestone that's left over. Your water probably tastes pretty good when you drink it from the tap.

[BRPORSCHE]

Originally Posted by MRM

Your water probably tastes pretty good when you drink it from the tap.

Yea but he probably has awfully dry skin from that hard water. Soft water is easier on the skin/hair.

[gtc]

Whoa! Is that duct tape? That seems really sketchy to me, considering the how hot these boilers can get.

[nostatic]

Originally Posted by BRPORSCHE

Yea but he probably has awfully dry skin from that hard water. Soft water is easier on the skin/hair.

I'm betting the next comment concerns hair product...

[911Freak]

Duct tape rules!
But it does gets gooey when hot, not sure I'd want pieces of goo circulating around that system, just saying.. I'm sure Gogar thought of that though

[Gogar]

Originally Posted by gtc

Whoa! Is that duct tape? That seems really sketchy to me, considering the how hot these boilers can get.

Under the duct tape there's a layer of foil-backed insulated 'pipe wrap' tape. Foil to the inside, and the duct tape just holds the pipe wrap tape in shape. It's pretty much identical to what they had on there, except they had clear fiber-tape on there, instead of duct.

You can see in the first pic, the pipe wrap tape inside-out, and fiber tape holding it together. I'm just trying to recreate that.

I feel ok about it.

[rsNINESOOPER]

Gogar-

I like the fix anything attitude, nice work! but...
I agree with the other comments about the duct tape as it seems a little iffy to use it in a high temp situation for safety reasons. Another thing to consider is that duct tape smells like (crap) burning plastic when exposed to high heat. As an alternative there is a cheap product which should do what you need it to do and its in a lot auto parts stores.
"muffler tape" or some such which is used to seal up pinholes etc in exhaust systems just downstream of the exhaust manifold after the collector. Its self adhesive and high heat resistance make it a possible solution to replace the duct tape.

When its up and running again you might find your coffee tastes funny without the secret sludge flavoring. My wife bought a used machine a couple years ago and I refurbished it for her and found stuff like that in the boiler that made me gag. I was bummed that I had a shot or two before it was cleaned. shivers.

Just 2cents

[Moses]

Originally Posted by Gogar

So, my Nuova Simonelli Microbar....

Struck me as funny! Good work on the repair. After ten years and thousands of espressos, my Capresso superautomatic died of multiple organ system failure. I boxed it up and sent it back to the factory. For a flat fee ($275-yikes!) They rebuilt the whole machine. Works like a charm.

[nota]

if you want no scale or deposits use distilled water
most simple home type filters will not pull out limestone

[Gogar]

Okay, I don't want you guys to worry about me, so I replaced the Duct with Aluminum "Flue Tape", so it basically turns that pipe-wrap tape into a little sheet of double-sided aluminum insulation. I think it looks a lot sexier. Probably won't smell as much, either. Thanks for the suggestions.






So, the boiler element is replaced and heats, still no steam.

So, now I have to move on in my search:

1. Perhaps the level probe in the boiler is bad, and the boiler is not filling up with water far enough. That might explain why the old element failed. Maybe it was dry and just got too hot and cooked itself until it broke.

2. The level probe is bad and the boiler fills up too much, but I think I would hear the machine trying to always fill the boiler.


3. (my guess) the solenoid that allows water INTO the boiler is bad and is not letting water into the boiler.


Fun stuff!

[pavulon]

That thing must really churn out the meth!!

[lm6y]

Can't help but think that if there was that much crud inside, the fill solenoid might have a clogged screen. Should be easy to check / clean. Had a washer that did that once. Cleaned the Stainless screen, and worked like a charm.

[Gogar]

Originally Posted by lm6y

Can't help but think that if there was that much crud inside, the fill solenoid might have a clogged screen. Should be easy to check / clean. Had a washer that did that once. Cleaned the Stainless screen, and worked like a charm.

Noted.

Since my last post I fired up the machine, and let the pump fill up the boiler(s).

For fun, there was a drain plug on the steam boiler (the one I'm working on.)

I turned off the machine and took out the drain plug.

NO WATER!

So, my guess is the "steam boiler fill solenoid," let no water into the steam boiler and it cooked itself until the element broke. And made the lime scale that much uglier.


I checked power to the solenoid, and found 40VAC.
It's a 117VAC solenoid, but I'm unsure of what the activation voltage should be.

anyhow, with voltage applied to the solenoid it didn't click, so
At the moment I have it apart and I'm cleaning it up. Maybe it was stuck.

The solenoid terminals do spec out the same as the other ones in the machine,

about 660 ohms across the coil.

[Gogar]

Well, I was out for some work and the coffee had to wait.

After cleaning the "Steam boiler fill" solenoid, It worked fine. Just to make sure, I swapped it with an identical solenoid in the machine and everything was ok.

So, that brought things down the line to the circuit board, again.

For every solenoid, there is an ALD112 12V power relay on the board.

After a little conversation with the tech at the Nuova Simonelli shop, It was determined that the last resort except for swapping out the board was to replace the relay.

So, I ordered up some ALD 112 relays from DigiKey but there was a 1-month lead. Which was fine, I was out for work anyway.

Got home today and the new relays were here! ($1.50 each, I got a few.)

Swapped a new one into the board and, VOILA! Turn on the machine, and the steam boiler fills and makes steam! Crisis averted one more time on this POS!


Much better than swapping the entire board, to the tune of $575.

[Tobra]

yikes, makes my 30 year old Krups look like the buy of the century.