Steam release keeps going off, steam boiler overfilling

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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damonbowe

#1: Post by damonbowe »

On my ECM Technica Profi IV that I repaired a few months ago, I'm having an issue where the steam boiler is overfilling and then blowing the release valve. It actually works pretty well in getting the steam back down and usually if I toggle the machine on and off or let steam of of the boiler, it's okay. But it has happened several times in the past few days and is concerning me.

In the past this might happen and would short out the circuit the machine was on. It turned out that part of that faulty circuitry was a heating element that needed to be replaced. Since replacing that, the steam valve, and the pstat, the machine has performed flawlessly until now.

I think the next thing to replace is the thermostat. I also purchased the entire wiring harness but it turns out that is kind of a hassle to replace in the machine, so I'm hoping to avoid using that part.

Any thoughts or advice on what I need to do to prevent this overfilling of the steam boiler?

Sw1ssdude

#2: Post by Sw1ssdude »

when you repaired the machine, did you tinker with the overpressure valve?

on my machine, the rubber gasket in the overpressure valve was as hard as an aspirine, i replaced it, then adjusted the valve with a bicycle pump to go off at 1.5 bar.

these valves also deteriorate. when rebuilding them, make sure they trip at a pressure HIGHER than the highest pressurestat setting, otherwise you'll blow steam before the pstat can switch off, and evaporate all water in the boiler. if your thermal fuse doesnt trip at that point, you'll burn out your heating element, if not your whole house..

Could you elaborate more on the steam boiler? it seems to me that the ECM has just one boiler...

Good Luck, send some pictures!
Lean Mean Caffeine Machine

Nick111
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#3: Post by Nick111 »

For the NS Musica the factory setting is 2.1 bar.

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damonbowe

#4: Post by damonbowe »

Sw1ssdude wrote:when you repaired the machine, did you tinker with the overpressure valve?

on my machine, the rubber gasket in the overpressure valve was as hard as an aspirine, i replaced it, then adjusted the valve with a bicycle pump to go off at 1.5 bar.

these valves also deteriorate. when rebuilding them, make sure they trip at a pressure HIGHER than the highest pressurestat setting, otherwise you'll blow steam before the pstat can switch off, and evaporate all water in the boiler. if your thermal fuse doesnt trip at that point, you'll burn out your heating element, if not your whole house..

Could you elaborate more on the steam boiler? it seems to me that the ECM has just one boiler...

Good Luck, send some pictures!
Problem is too much steam in the steam boiler. This happens about once per week, more or less. The steam release is happening as designed and I recently changed that part out including the gasket. The machine no longer shorts out because everything is operating as it should. The machine never did boil off all the water to short out, it was just a worn out heating element.

Sorry my explanation above is terrible. I read too many posts and half the time I can't understand the lingo tossed around on HB so my brain was jumbled ha ha! Plus I am not great at writing. The prospect of doing more repairs on this machine is not exciting to me, I have to tell ya. But I need to get the machine working because my wife is threatening to kick the machine out if I can't get it completely under control.

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stefano65
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#5: Post by stefano65 »

Nick111 wrote:For the NS Musica the factory setting is 2.1 bar.

that value is incredibly high for operational, I would say that
it is when the safety valves is calibrated and
opens when the pressure is climbing without a stoppage
not the operating pressure
Stefano Cremonesi
Stefano's Espresso Care
Repairs & sales from Oregon.

Sw1ssdude

#6: Post by Sw1ssdude »

Do you mean the boiler with 'steam boiler'?, i didnt found another boiling device for steam on a ecm technika ( its a dual boiler, right?)

there is no such thing as too much steam, just too much pressure. water under pressure gets way hotter than at atmospheric pressure in your tea kettle, around 120°C at 1 bar pressure. At 2.1 Bar water is around 135°C.

while flowing out of the machine, the brew water cools down (single Boiler) or heats up (dual boiler) to the desired 88-92°C for espresso.

Since i have little to no experience about dual boilers (but i'm an engineer, so i feel confident..: ), the following is a guess:
Dual boilers rise to a higher pressure ( = higher temperature) to effectively heat up the brew water in the heat exchanger while making espresso, therefore they need a pressure release valve at such high pressure (like the mentioned 2.1 Bar for a Nuova Simonelli Musica), because their operating pressure is higher than on a single boiler (to be verified..: ).

My Olympia club is a single boiler with a pstat set to 1Bar. I set the Pressure release valve myself to 1.5 Bar, which is above the highest setting of the pstat.

So the maximum pressure can vary on different machines,
in any way, the pressure release valve makes sure that your boiler doesnt explode if your pstat has a malfunction and doesnt turn off the heating.

so if your pressure release valve gets off, then:
- your heater gets way too hot, which means your pstat is faulty. by the way, what pressure is your machine set to?
- the pressure treshold of your pressure release valve is set too low for your machine (this would be bad, it would deliberately blow steam at operating temperature)
- your pressure release valve and your pstat are fine, but their tresholds are too close to each other, so it trips occasionally.

oh, the first reading on the manometer is usually wrong when turning the machine on, because some air might be trapped in the boiler. in this case, both pstat and manometer read the pressure of an air-steam-mixture, which varies from the pressure of a pure steam phase (thermodynamics are awesome!)
so heat up your machine, blow some steam (and air) from the steam wand, and then you get the correct readings for both pstat and manometer.

i hope this helps in any way...
Lean Mean Caffeine Machine

Nick111
Supporter ♡

#7: Post by Nick111 »

stefano65 wrote: that value is incredibly high for operational, I would say that
it is when the safety valves is calibrated and
opens when the pressure is climbing without a stoppage
not the operating pressure
I am not an engineer or a technician,therefore I do not have a personal opinion.
I do got the figure from the NS Musica service manual.

Nick111
Supporter ♡

#8: Post by Nick111 »

Sw1ssdude wrote:Do you mean the boiler with 'steam boiler'?, i didnt found another boiling device for steam on a ecm technika ( its a dual boiler, right?)

there is no such thing as too much steam, just too much pressure. water under pressure gets way hotter than at atmospheric pressure in your tea kettle, around 120°C at 1 bar pressure. At 2.1 Bar water is around 135°C.

...
Very nice presentation of the subject.
Thank you.

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stefano65
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#9: Post by stefano65 »

Nick111 wrote:I am not an engineer or a technician,therefore I do not have a personal opinion.
I do got the figure from the NS Musica service manual.
i just looked at one on ,ne and yes they are referring to when the valves OPENS just like I was assuming
a steam boiler if only steam will be set a 1,5 or so ton other machines, otherwise a "special" safety valve will be needed only for them,
Stefano Cremonesi
Stefano's Espresso Care
Repairs & sales from Oregon.

Nick111
Supporter ♡

#10: Post by Nick111 »

Yes indeed, the boiler pressure gauge of my Musica has a band between 1.0 and 1.5.I run it at 1.3 most of the time.
I assume the Safety pressure release valve is calibrated as per manual at 2.1.