Our Valued Sponsor
OpinionsConsumer ReviewsGuides and How TosCoffeeGeek ReviewsResourcesForums
Espresso: Espresso Mods and Restorations
Isomac Relax Automatica troubleshooting - help required
Find the Right Machine...
Package deals on the best machines from Izzo, Quick Mill, Rocket, La Marzocco & more.
www.clivecoffee.com
 
Not Logged in: Log In to Postlog in
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered  
Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Discussions > Espresso > Espresso Mods > Isomac Relax...  
view previous topic | view next topic | view all topics
showing page 1 of 4 last page next page
Author Messages
AuxMemes
Senior Member


Joined: 18 Jul 2012
Posts: 14
Location: Gers, France
Expertise: Professional

Espresso: Isomac Relax Automatica
Grinder: Rancillio Rocky
Posted Wed Jul 18, 2012, 8:34am
Subject: Isomac Relax Automatica troubleshooting - help required
 

We have an Isomac Relax Automatica that has stopped working after 5 years perfect service.  It suddenly went overpressure starting an espresso.  Normaly the pressure rests at approx 1.1 and slowly drops during a brew until the heater comes on. Now it immediately leaps to 2+ even with the Pf removed, less than normal water/pressure at the group, the OPV opens releasing the pressure/water into the tray.

Descaled and backwashed as normal but no change.

After removing the cover I could see that the pressure release at the top of the group is closed during the brew and releases a little pressure on stopping the brew.  I assumed this meant the valve at the head is working correctly and the group isn't blocked. I dismantled anyway and all seems ok at the group and group valve.

This is all guesswork as I know nothing of the inside of these machines.  Does the excess pressure from the pump return water to the tank as there's no sign of this happening? Could this valve have stopped working?  Is it something else completely???
back to top
 View Profile Visit website Link to this post
JtothaR
Senior Member
JtothaR
Joined: 20 Dec 2010
Posts: 753
Location: Las Cruces, NM
Expertise: I live coffee

Espresso: NS Appia, Oscar
Grinder: K10, Lusso, GM 875
Drip: Pour-Over, FP, Toddy
Roaster: Agapao, Metropolis, CC
Posted Wed Jul 18, 2012, 11:05am
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

AuxMemes Said:

We have an Isomac Relax Automatica that has stopped working after 5 years perfect service.  It suddenly went overpressure starting an espresso.  Normaly the pressure rests at approx 1.1 and slowly drops during a brew until the heater comes on. Now it immediately leaps to 2+ even with the Pf removed, less than normal water/pressure at the group, the OPV opens releasing the pressure/water into the tray.

Descaled and backwashed as normal but no change.

After removing the cover I could see that the pressure release at the top of the group is closed during the brew and releases a little pressure on stopping the brew.  I assumed this meant the valve at the head is working correctly and the group isn't blocked. I dismantled anyway and all seems ok at the group and group valve.

This is all guesswork as I know nothing of the inside of these machines.  Does the excess pressure from the pump return water to the tank as there's no sign of this happening? Could this valve have stopped working?  Is it something else completely???

Posted July 18, 2012 link

Since brew pressure is normally 8-10 bar, I will assume you are referring to boiler pressure. That's why you cant find anything wrong with the group is because the problem is with the boiler's pressure regulation (also known as the pressurestat). Over time the pressurestat wears out and can stick in the closed position causing the boiler to overpressurize/overheat. It will most likely need a replacement.

 
Load and Lock.
back to top
 View Profile Link to this post
AuxMemes
Senior Member


Joined: 18 Jul 2012
Posts: 14
Location: Gers, France
Expertise: Professional

Espresso: Isomac Relax Automatica
Grinder: Rancillio Rocky
Posted Wed Jul 18, 2012, 12:12pm
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

Just an assumption but the "pressurestat" only controls the heater? The heater switches off ok at the correct pressure and as the heater is off when expresso is brewed the over pressure is caused by the pump, so the "pressurestat" is probably ok.

btw the steamer and hot water work ok.
back to top
 View Profile Visit website Link to this post
JtothaR
Senior Member
JtothaR
Joined: 20 Dec 2010
Posts: 753
Location: Las Cruces, NM
Expertise: I live coffee

Espresso: NS Appia, Oscar
Grinder: K10, Lusso, GM 875
Drip: Pour-Over, FP, Toddy
Roaster: Agapao, Metropolis, CC
Posted Wed Jul 18, 2012, 12:14pm
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

AuxMemes Said:

Just an assumption but the "pressurestat" only controls the heater? The heater switches off ok at the correct pressure and as the heater is off when expresso is brewed the over pressure is caused by the pump, so the "pressurestat" is probably ok.

btw the steamer and hot water work ok.

Posted July 18, 2012 link

That sounds like the ol' "Split in the side of the HX tube" if that's truly whats happening. :(

 
Load and Lock.
back to top
 View Profile Link to this post
AuxMemes
Senior Member


Joined: 18 Jul 2012
Posts: 14
Location: Gers, France
Expertise: Professional

Espresso: Isomac Relax Automatica
Grinder: Rancillio Rocky
Posted Thu Jul 19, 2012, 12:45am
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

I don't think any tubes are split.  There's no sign of any leaks of steam or water?
back to top
 View Profile Visit website Link to this post
calblacksmith
Moderator
calblacksmith
Joined: 25 Nov 2007
Posts: 7,950
Location: Riverside, Ca, U.S.A.
Expertise: I live coffee

Espresso: ECM Vene. A1, La Cimbali M32
Grinder: Azkoyen Capriccio, Major
Vac Pot: 40s era Silex
Drip: Msl. Com. brewers
Roaster: gave it a try, decided no
Posted Thu Jul 19, 2012, 5:16am
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

You are mixing things up. I really think JtothaR has it right, you said....

AuxMemes Said:

.. Normaly the pressure rests at approx 1.1 and slowly drops during a brew until the heater comes on. Now it immediately leaps to 2+ even with the Pf removed, less than normal water/pressure at the group, the OPV opens releasing the pressure/water into the tray.

Posted July 18, 2012 link

The PF has NO connection to boiler temp (pressure of 1.1) so are you saying that when you start the brew process, the pressure goes up OR are you saying that just turning the machine ON the pressure goes up?

The boiler pressure of 1.1 is the temp of the boiler and is regulated by the Psat. The only way this static pressure (before starting the brewing process) can rise without you making adjustments to raise it, is for the Pstat to be sticking in the heat position.

If the boiler pressure is 1.1 at static condition THEN rises when you start the brewing process, the HX tube likely has a hole or crack in it and thus the pump is pressurizing the boiler through the leaking HX tube.

You have two gauges on the machine and they each show data that is different than the other.

The static gauge (the one that shows about .8 to about 2 bar) is the temp of the water in the boiler measured in BAR of pressure (not C or F deg)

The gauge that goes from about 6 bar to about 15 bar is the pressure of the pump as it pushes water through the brew system, it should show line pressure of the brew water system when the pump is off. If your supply water pressure is 3 bar, then the gauge will show 3 bar of pressure with the pump off (if you are using a water tank and are not plumbed in, it will show 0 as there is no line pressure in the water tank system) but will rise to the regulated brew pressure of about 9 bar (or whatever you have your brew pressure set at) when you start the pump for brewing.

Two different gauges for two different systems in your machine. If when you turn the pump on, you get a rise in your temp gauge in a HX machine, your HX tube has a split in it where it passes through the boiler (and thus no leaking water outside the machine) and this additional pressure will show on the temp gauge, pegging it and it will cause the safety valve to pop off to bleed of excess pressure that the boiler was not designed to handle.

OH, BTW, it is spelled eSpresso, not eXpresso, a professional would know that ;<P

AuxMemes Said:

Just an assumption but the "pressurestat" only controls the heater? The heater switches off ok at the correct pressure and as the heater is off when expresso is brewed the over pressure is caused by the pump, so the "pressurestat" is probably ok.

btw the steamer and hot water work ok.

Posted July 18, 2012 link

The temp of the boiler is maintained by the Pstat and is independent from the brew system, the heater can be either on or off while brewing, it does not turn off for brewing. There is nothing that switches it off when you  start to brew espresso so how do you know it is off when you are brewing?

 
In real life, my name is
Wayne P.
Anything I post is personal opinion and is only worth as much as anyone else's personal opinion. YMMV!

Feed the newbs, starve the trolls and above all enjoy what you drink!
back to top
 View Profile Visit website Link to this post
AuxMemes
Senior Member


Joined: 18 Jul 2012
Posts: 14
Location: Gers, France
Expertise: Professional

Espresso: Isomac Relax Automatica
Grinder: Rancillio Rocky
Posted Thu Jul 19, 2012, 7:29am
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

The pressure goes up on starting the brew process.

I didn't realise the HX tube went through the boiler, I'll look into this.

There's only 1 gauge on my machine, the boiler pressure, as seen here http://www.espressocoffeeshop.com/store/product127.html

BTW it's spelt expresso here in France, by everyone including professionals ;)

I didn't say the heater turned off for brewing, I said the heater was off at the start of the brew.  You can tell this because the little green light comes on and the funny boiling noise stops and the lights in the bar get brighter.
back to top
 View Profile Visit website Link to this post
__________
Senior Member


Joined: 12 Sep 2006
Posts: 924
Location: .
Expertise: Just starting

Espresso: Machine now fixed ;o)
Grinder: None
Vac Pot: None
Drip: None
Roaster: None
Posted Thu Jul 19, 2012, 11:16am
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

It does sound likely that there is a leak in the heat exchanger inside the boiler; so when the pump switches on pressure is leaking out into the main part of the boiler.   This will also switch off the heater if it was on to start with, as it will open the pressurestat contacts.  I am guessing that the reading of "2" on the gauge is as high as the gauge will go ?

What happens if you open the hot water valve while the pump is running ?  Provided the portafilter is in place with either coffee or a blind filter in it, if the heat exchanger is leaking you should find the water comes out with  more pressure than normal (please be very careful if you try this !)

I think this is likely to be a repair for the professionals if the heat exchanger is indeed leaking.

After 5 years you might find it difficult to get the manufacturer or supplier to fix it free of charge, even if the law in the EU says that items like this should have a reasonable life.  It is worth a try though.

Bonne chance.
back to top
 View Profile Link to this post
calblacksmith
Moderator
calblacksmith
Joined: 25 Nov 2007
Posts: 7,950
Location: Riverside, Ca, U.S.A.
Expertise: I live coffee

Espresso: ECM Vene. A1, La Cimbali M32
Grinder: Azkoyen Capriccio, Major
Vac Pot: 40s era Silex
Drip: Msl. Com. brewers
Roaster: gave it a try, decided no
Posted Thu Jul 19, 2012, 11:49am
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

Some machines have one gauge, some have two and others don't have any. I did not look at your specific machine but if you had two gauges they would have reacted the way I described. It does sound like the HX tube has an internal leak buy your description of what happens .. when.

You might get lucky and have a HX tube that can be repaired easily but many boilers have a sealed boiler which would require major surgery on the boiler to repair the HX tube. I hope you are the benefactor of the former rather than the unlucky owner of the latter.

Rob hit the nail on the head with the cycling of the heater in the brew process. The temp is set by the pressure inside the boiler, nominally 1.1 bar. If the boiler is too cold, say 1.0 bar, the Pstat will turn the heater on until the set pressure is reached at which time, the water is at the desired temp. If your HX tube is leaking and you start the brew cycle, the pump pressure will cause a spike in the pressure in the boiler and the Pstat will react to the additional pressure by turning off the heater (it "thinks" the water is hot enough and and the water needs no more heat) which is why the green light for your heater turns off (not all machines have lights that show when the machine is heating). This also explains why the safety valve releases pressure, the valve is set to a pressure that the boiler will never see in normal service but is below the pressure design of the boiler so when the pump adds pressure into the boiler, the safety valve reacts as if the water was too hot and the valve opens, venting the excess pressure to the air before any damage can happen to the boiler.

Often when this happens it is because the machine was left in an unheated space in the winter and the water froze. I know you did not indicate this happened and I have nothing to offer as to why this could have happened when the machine is in service every day, other than possibly a manufacture defect that has taken years to appear. Even if it is a faulty part, it is unlikely that you will get any help with the repair and often when paying a shop to do the work (I don't know if you are able to do the work or not) a repair like this cost will be enough for you to consider replacement of the machine rather than repair.

Good luck!

 
In real life, my name is
Wayne P.
Anything I post is personal opinion and is only worth as much as anyone else's personal opinion. YMMV!

Feed the newbs, starve the trolls and above all enjoy what you drink!
back to top
 View Profile Visit website Link to this post
AuxMemes
Senior Member


Joined: 18 Jul 2012
Posts: 14
Location: Gers, France
Expertise: Professional

Espresso: Isomac Relax Automatica
Grinder: Rancillio Rocky
Posted Thu Jul 19, 2012, 1:24pm
Subject: Re: Isomac Relax Automatica troubleshooting - help required
 

OK I think I understand a little more now.  It sounds like the HX could be leaking, but isn't there one other possibility?  There must be an inlet to the boiler from the pump to maintain the boiler level.  If the valve or whatever controls the flow of water to the boiler from the pump has failed wouldn't that cause over-pressure in the boiler evertime the pump was started and reduce the water flow to the group?
back to top
 View Profile Visit website Link to this post
showing page 1 of 4 last page next page
view previous topic | view next topic | view all topics
Discussions > Espresso > Espresso Mods > Isomac Relax...  
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered     Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Not Logged in: Log In to Postlog in
Discussions Quick Jump:
Symbols: New Posts= New Posts since your last visit      No New Posts= No New Posts since last visit     Go to most recent post= Newest post
Forum Rules:
No profanity, illegal acts or personal attacks will be tolerated in these discussion boards.
No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum.
No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek.
No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum.
Who Can Read The Forum? Anyone can read posts in these discussion boards.
Who Can Post New Topics? Any registered CoffeeGeek member can post new topics.
Who Can Post Replies? Any registered CoffeeGeek member can post replies.
Can Photos be posted? Anyone can post photos in their new topics or replies.
Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts.
Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
Cafe Solutions
Commercial sales and service, nationwide installation, equipment leasing options.
www.seattlecoffeegear.com
Home | Opinions | Consumer Reviews | Guides & How Tos | CoffeeGeek Reviews | Resources | Forums | Contact Us
CoffeeGeek.com, CoffeeGeek, and Coffee Geek, along with all associated content & images are copyright ©2000-2014 by Mark Prince, all rights reserved, unless otherwise indicated. Content, code, and images may not be reused without permission. Usage of this website signifies agreement with our Terms and Conditions. (0.282972812653)
Privacy Policy | Copyright Info | Terms and Conditions | CoffeeGeek Advertisers | RSS | Find us on Google+