Isomac HX - No steam / pressure after a while

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Livin
Posts: 53
Joined: 12 years ago

#1: Post by Livin »

*UPDATED with more testing/info*

The past week or so I've been seeing problems with my machine cycling properly.

When cold, or being off for a while and 'warm', it properly gets to pressure/temp and sometimes for even 2-4 pulls. BUT ~60-70% of the time it will not cycle back up to proper pressure after a few pulls and/or steaming milk.

Sometimes if it having the problem (no steam, low heat) after ~20-30 minutes it will cycle properly again. I can not find any pattern since this is not consistent.

I played with the Mat-er Pressure Stat setting (I had previously reduced the pressure to reduce cooling flush need) and this does not seem to make any difference.

I run regular maintenance:
- flush with Cafiza once/month (after 60-80 shots pulled)
- use only RO water for brewing.
- today I did a full descale and removed the mushroom value parts... they were clean as a whistle.


Thoughts on what to check next?

thx!

Beenbag
Posts: 330
Joined: 11 years ago

#2: Post by Beenbag »

Are you saying that the heater element is switching off at a lower pressure(temperature) than normal ?
If so then i suggest you simply fit a new pressurestat as a first try at a fix.
Those Mater units are not ultra reliable and are often the first thing to fail. !

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erics
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#3: Post by erics »

Those Mater units are not ultra reliable and are often the first thing to fail. !
I sorta disagree :) . . . because, the majority (all?) of the US Isomac units are fitted with a SSR (solid state relay) to complete the heating element circuit. The MA-TER has a very low current draw.

Tis time to undress this machine, take a few pics, and look closely at the SSR connections.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

Livin (original poster)
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#4: Post by Livin (original poster) »

erics wrote:Tis time to undress this machine, take a few pics, and look closely at the SSR connections
How could the SSR connections themselves could be a problem?

The unit is usually good (holds pressure and temp) for a while then it has issues after a few pulls and/or steams.

I let the unit warm up for at least 1 hour before I use it in the morning and it seems to be fine... the issue seems to be after some continuous use.

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erics
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#5: Post by erics »

How could the SSR connections themselves could be a problem?
I have worked on several Isomac machines and my response was based on that experience.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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Compass Coffee
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#6: Post by Compass Coffee »

I agree with Erics. Part of basic trouble shooting, especially electrical/electronic issues, is cleaning and reseating all connections. Thermal contraction/expansion can cause intermittent on a loose or corroded connection.
Mike McGinness

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erics
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#7: Post by erics »

Thermal contraction/expansion can cause intermittent on a loose or corroded connection.
As per the below pic . . . relatively easy to check.

Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

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Compass Coffee
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#8: Post by Compass Coffee »

erics wrote:As per the below pic . . . relatively easy to check.
That pic would/could definitely show the result of a bad connection, which caused greater resistance causing heat and melt down. IF when symptom first occurred and SSR visually looked at there would likely be no visual indication of a bad connection. Hence the need to physically disconnect, clean and reconnect all connections in a suspect circuit to often prevent that type of thing!
Mike McGinness

Beenbag
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#9: Post by Beenbag »

erics wrote:I sorta disagree :) . . . because, the majority (all?) of the US Isomac units are fitted with a SSR (solid state relay) to complete the heating element circuit. The MA-TER has a very low current draw..
If the heater is actually switching off at a lower pressure, ( we dont actually know as Livin hasnt told us yet)
Then it may simply be the "pressure" side of the Mater that has gone random ..which has been my experience with those units....even brand new Mater's have done this on me.
They have a known reputation for it. :shock:

Livin (original poster)
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#10: Post by Livin (original poster) »

Back from vacation and updated info...

I think the problem is the Resettable Safety Thermostat has gone bad.

See the photo for what I found when I looked inside.

I bypassed this device and the machine seems to be steaming like mad now... of course, I'm careful not to run it long to ensure it does not overheat.

I have read some of these are not properly sized for the machines they are on... anyone have a recommendation specific to the Isomac Millennium? Or should I just replace it with the same cutoff temp?

thanks guys.

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