Nuova Simonelli Ellimatic continuous steam from grouphead - Cracked HX?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
yokusan
Posts: 4
Joined: February 2nd, 2018

Postby yokusan » Feb 02, 2018, 9:44 am

Dear HB users,

I hope you can help me to identify the source of my problem with my recently acquired Nuova Simonelli Ellimatic:

The Ellimatic looked clean and in good state when I bought it a few weeks ago. However, when I pulled shots I was getting a lot of steam from the grouphead and was not able to pull a nice espresso due to heavy channeling. I thought this might be due to a faulty pressurestat and I therefore exchanged the installed CEME pressurestat with a new MATER which was preset to 1.1 bar. In the meantime I also added a vacuum breaker in the line of the pressurestat and a new OPV because the old one was closed and stuck.

However, installing the new and working pressurestat did not really solve the problem. And I am afraid that this is due to a crack in the HX inside the boiler. Or could it be due to some malfunctioning valve (2-way/3-way)? That would be much easier to handle.

Here are some examples of the steam coming through the brew line:

First the steam through the group head:



The steam/bubbles also come through the OPV when I put a blind filter into the portafilter and the boiler is at 1.1. There are no bubbles if I do it when the machine is cold.



I know everythings hints to a cracked HX. I just would know if it could maybe be something different.

Just for information for other Elli and Ellimatic users, I attached a picture of how I installed the vacuum breaker in the line of the pressurestat without having to intensively modify the machine. It works nice.

Image

Thank you all in advance,

Regards from Cologne (Germany),

Johannes

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kolu
Posts: 163
Joined: June 4th, 2013

Postby kolu » Feb 02, 2018, 6:15 pm

run the extraction with blindfilter in portafilter when having the machine on. the steam boiler pressure should not drop drastically.
if it drops and keeps on falling, there might be cold water introduced to the boiler although no water run through the group.
also, if you keep it like that it could blow the safety valve once the boiler overfills.

it could also be leaking boiler fill valve.

check with blindfilter first.

yokusan
Posts: 4
Joined: February 2nd, 2018

Postby yokusan replying to kolu » Feb 03, 2018, 6:18 am

Dear Kolu,

that is exactly what I did in the second video. The water is then flowing through the OPV and air is coming out with the water in the brew line. In addition, the heating element is constantly on as signaled by the glowing lamp. This is equivalent with a constant pressure drop detected by the pressurestat.

How would air get through a leaking boiler fill valve into the brew line? Isn't the filling hose of the boiler at the bottom in water?

Nunas
Posts: 533
Joined: June 4th, 2015

Postby Nunas » Feb 03, 2018, 4:17 pm

It sure looks like boiler water getting into the heat exchanger. You need to do a pressure test. Jury rig a tire pump to the HX intake line. Those little battery ones with the inbuilt pressure gauge are ideal. Run the pump to clear the water then fit your portafilter with a blind basket. Open the top of the boiler and pump up the HX. You want to see it hold the pressure. If the pressure does not hold then look in the boiler; if the crack is bad enough you may see bubbles. I've been told you can also do it with food dye, but have never tried. To do it, open the boiler and add a bit of food dye, then close the boiler. Run the machine and capture the water. Since HX machines use only reservoir water, not boiler water, to make coffee, if any colour comes through you know boiler water is getting into the HX.

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kolu
Posts: 163
Joined: June 4th, 2013

Postby kolu » Feb 03, 2018, 7:31 pm

yokusan wrote:that is exactly what I did in the second video. The water is then flowing through the OPV and air is coming out with the water in the brew line.

first of all - remember that the pressure in HX line is way higher than in your boiler (10 bar vs. 1) so if there is any leak, it will happen the other direction. is your OPV set right?

yokusan wrote:In addition, the heating element is constantly on as signaled by the glowing lamp. This is equivalent with a constant pressure drop detected by the pressurestat.

no, that just means you're cooling down boiler - depending on crossflow design and OPV placement it could be well just a cooling effect of heat exchange. pressostat doesn't sense dynamic changes of pressure (drop), sorry.

yokusan wrote:How would air get through a leaking boiler fill valve into the brew line? Isn't the filling hose of the boiler at the bottom in water?


yea, common misconception. if your HX is broken, then nothing is really getting in - it rather leaks out (if your OPV is set right). I suspect that the air you see there is not from boiler.


you can do real test to determine of your HX is broken (with cold machine):

1) disconnect heating element
2) disconnect boiler fill solenoid (remove the coil or wires)
3) remove the connection between boiler and fill valve
depending on it's position in machine, the boiler might drain (good!)
4) find lowest cap/connection/whatever on boiler that you could unscrew to let the remaining water out, drain boiler and keep it open
5) fire up the machine

what is going to happen:
machine sees low water level in boiler
it starts filling (runs pump and opens fill valve)
3 way valve is closed, fill valve is disabled (step 2), so the HX system will reach the maximum pressure allowed by OPV (should be at least 9 bar)
- if there is water coming out of fill valve-boiler connection, replace this valve
- if there is water coming out of the open port on boiler (step 4), HX might be shot and you should disconnect the boiler for proper inspection
- if there is water coming out of OPV and nothing else happen, check the OPV pressure. if it's fine (9+ bar), you're fine as well as your HX and the problem is elsewhere

Nunas
Posts: 533
Joined: June 4th, 2015

Postby Nunas » Feb 04, 2018, 6:00 pm

Your situation has certainly got me scratching my head! Not that I'm any kind of expert (far from it), but I can't resist a challenge :) . From your video, the OPV on your machine appears to be mounted on the 'hot' side of the HX (which is a bit unusual I think). Thus, your machine will always send heated surplus brew water back to the reservoir. However, you're not getting heated water; you're getting heated water and air (or maybe steam). This could be explained by a cracked HX. The 'water dance' normally ends after a few seconds flushing; yours seems unending. Since there is no PF, the pressure in the brew line is minimal. The pressure in the boiler is about 1-bar. So, if there is a crack, it would also explain the continuous steam from the bare group head. Moreover, we can deduce the crack is likely above the water line. Perhaps there is another explanation?

Maybe another little test, if you have not yet checked the HX for a leak. If you disconnect the heater and run with a blind basket, and there is a crack in the HX, sooner or later the boiler would have to overfill.

Watching with interest... :)

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plindy
Posts: 87
Joined: January 29th, 2011

Postby plindy » Feb 05, 2018, 5:03 am

would venture a guess, HX safety valve is toast

have you seen?

and

yokusan
Posts: 4
Joined: February 2nd, 2018

Postby yokusan » Feb 05, 2018, 6:37 am

@Kulo and Nunas:

Thanks for the nice description how to identify a cracked HX. I unscrewed the 2-way solenoid and will give it a thorough cleaning first to see if it may be the culprit. If it is not (what I am expecting), I will do a routine similar as mentioned by Nuna:

- Disconnect heating element (I hope I do it right)
- Unscrew connection to pressurestat at the upper side of the boiler
- Run pump with a blindfilter in PF

If the HX is cracked, the boiler should fill to the level where water runs out of the hose of the pressurestat connection.

@plindy

Do you mean the OPV? I installed a new one and it seems to do its job. It is one the "hot" side of the HX as identified correctly by Nunas.

Thanks a lot,

Johannes

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plindy
Posts: 87
Joined: January 29th, 2011

Postby plindy » Feb 06, 2018, 5:57 am

OPV correct
should hold 16 bar before opening

Nunas
Posts: 533
Joined: June 4th, 2015

Postby Nunas » Feb 11, 2018, 1:47 pm

Johannes, what happened; is it working now...I'm sure I'm not the only one anxious to hear the outcome :) .

 
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