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Espresso machine problems
seehad
For a while I was experiencing some weird issues with my espresso machine. For now, it's settled on one in particular. I have a Isomac Relax and when I pull shots starts out fine and hits 9.5 bars and then after about 5 seconds it creeps down to 6 and stays there. This is regardless of grind and tamp. If I put the blind portafilter in, it stays consistent at 9.5 bars. FWIW, the hot water tap also drips every few minutes when shut.
Any thoughts?
 
seedlings
Does that model have a backflush / 3-way valve? May have a bit of a leak?

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Koffee Kosmo
At worst I feel you need to replace the OPV valve
Possibly a broken or weak spring
or remove & pull apart & clean then re calibrate the OPV bar setting

If all is fine with the blind filter the water pressure becomes its own seal
However with water running through the puck the ORV relaxes to its current resistance point

If this model is a semi automatic it could also be an electronic circuit board problem

KK
Edited by Koffee Kosmo on 05/25/2009 6:24 PM
I home roast and I like it. Designer of the KKTO
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Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
seehad
OPV. Is that the same thing that I used to adjust the brew pressure? They call it an expansion valve. About 6-8 months ago it was down to 8 bars with the portafilter so I adjusted it up to 9.5.
I'm going to pick up some citric acid this afternoon so I can descale it.
Edited by seehad on 05/26/2009 11:51 AM
 
Koffee Kosmo

Quote

OPV. Is that the same thing that I used to adjust the brew pressure?


Yes OPV stands for Over Pressure Valve or Expansion Valve

This site has info on how it works
http://coffeetime...sure-valve

KK



I home roast and I like it. Designer of the KKTO
Roaster Build information
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Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
seehad
Great read!
I have an OPV very similar to the Izo Vivi (Andrejo Premium)

Currently I'm 12 hours into a 24 hour descale with the citric acid. I pulled off the screen from the hot water tap and there was a couple large chunks of scale. If that doesn't fix it, i will look at replacing the OPV.
 
seehad
Well I pulled off the OPV and cleaned it up. I powered it up and the boiler filled. There was minimal pressure at all so I tightened the OPV. Now the boiler wont fill. I can engage the pump with the drink button but that's it.

Here's a link the diagram of what I'm working on:
http://espressocare.com/PDF-Files/PDF-Schematics/Isomac/RelaxComplete.pdf
 
seehad
Well this is a kick in the pants. Seems when I was adjusting the OPV after assembling everything, I bridged two pins on the electronics with a nice hefty drop of water. Chris coffee confirmed the two pins tell the autofill and heater to turn on.
seehad attached the following image:
giemme.jpg
 
Koffee Kosmo
By the time it's finished you will have a new machine

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
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Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
seehad
It just went into a box until someday when I can afford to have someone who knows what they're doing fix it. I'm feeling pretty [email protected] volatile about the whole situation right now.. doesn't help that I quit smoking 3 days ago.
 
seehad
Wow that was a fun night! Still haven't smoked.

For $176 I can replace the Giemme controller.
Couldn't I just PID it and do everything the Giemme does while adding temp control for the same cost?
 
Koffee Kosmo
I suppose you could PID to make it a
Hot rod espresso machine

Give Jim Gallt a call he normally makes them for Sylvia but I am sure it cant be that hard??

http://www.pidkit...

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
seehad
So I called espresso parts source and was told that the first transistor would have been the one to take the hit had those pins been bridged. I opened it up to find that I had actually bent two of the transistors down which pulled the middle pin out from the transistor. I just ordered 5 replacements for 90 cents. Fingers crossed!
 
Koffee Kosmo
Seehad
Its sounding better every day with every post

That must do wonders to the quit smoking campaign
Fingers crossed for you mate

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
 
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