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Izzo Alex has gone cold...slowly!

Postby Alex G on Mon Dec 22, 2008 10:58 pm

I've had my Izzo Alex for about a year and a half. A little while ago (after the warranty was up!) it started acting strangely, and as of right now it is completely cold! When it started acting up, here's what happened:

When I turned the machine on, all the electrical stuff seemed to be working - the front light came on, if the boiler level was low the auto-fill kicked in and filled to what seems normal, if I lifted the grouphead lever the pump activated normally and water comes out the grouphead normally. The problem seems to be the heating element itself. But it didn't fail all at once. The Izzo Alex was acting kinda funny.

From a cold start when I turned the machine on I could hear the element start to raise the temp of the water - sometimes it would heat up enough to push up the little pressure relief valve on top of the boiler. Sometimes it'd heat up all the way to .9 bar where I have it set. Sometimes it would even cycle in a normal fashion for a short while. BUT - no matter how far into the heating cycle it got, at some point the heat cut out even though the machine was still on. It dropped to 0 bar. The light on the front stayed on (red only) and the pump still worked... just no heat. When this happens, the machine wouldn't heat up again until it was completely cold again.

This got worse and worse until now I get no heat at all no matter what.

I've taken all the panels off and checked all the wiring connections. No sign of shorting or fires, all the spade connectors seem fully connected, no plumbing leaks on boiler or anywhere else - everything looks perfect. Today I removed the heating element and tested it for continuity and was surprized to see that it tested OK. I do not have a multimeter, should I test this further? Also, it just so happened that I had a spare Ma-Ter XP110 pStat (same as original) so I swapped that out. I even polished the spade connectors on the Sirai solenoid.

NO LUCK!!! I'm very interested to hear your thoughts on what may be going on inside my poor Izzo
I've included a few images taken today inside my machine.

Thanks for helping.
Alex.
ImageImageImageImageImage
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Postby eastpresso on Mon Dec 22, 2008 11:38 pm

Sorry to hear about your problem - did you contact your dealer?

Could be the heating element, check this one:

http://www.home-barista.com/espresso-machines/wega-mini-nova-not-heating-t7169.html

If you do a search you will find some more threads :

http://www.home-barista.com/forums/search.php?keywords=heating+element+resistance&terms=all&author=&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

Good luck!
Bernhard
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Postby erics on Tue Dec 23, 2008 12:58 am

If your red light is on, that tells me the pstat is receiving power and is "trying" to send it to the element.

An inexpensive digital multi-meter will be necessary for the following:

When the machine is in its trouble state, check for voltage at the heating element - you should be reading line voltage (110 V) between either terminal and ground. You will probably read 0.

Now check for voltage at the safety thermostat which is next to the heating element in your pic. Both terminals should read line voltage. The safety thermostat is designed to pop open (and stay open until reset) at high temperature but an errant acting safety thermostat would not be terribly unusual.
Skål,

Eric S.
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Postby Alex G on Tue Dec 23, 2008 8:32 am

Eric

Thanks for taking the time to help me out! I will purchase a multimeter today and perform the tests you suggested (if I can get through the mall crowds!). As a side note, when you mentioned the thermostat I went and took a closer look at it. The little red button did not appear to have been popped/triggered. I gave it a push with my finger and it did not depress. I'm assuming that that means it was in its 'normal' state. I'll still do the voltage check though to see if it's faulty. I'll report back with my findings.

Thanks again.
Alex.
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Postby erics on Tue Dec 23, 2008 10:45 am

That's correct. The little red button is supposed to "pop" on a high temperature condition and a reset operation is performed just as you described. Of course, then you are supposed to try and determine what caused the malady in the first place. I don't recall ever seeing a post wherein the safety thermostat was determined to be faulty and, admittedly, that might have been stretching it a bit on my part BUT ya never can tell.

Since you have demonstrated that you are skillful when it comes to machine disassembly, your problem will hopefully be solved in very short order. BTW, sometimes those heating element threads need a wrap of teflon tape to seal properly. I realize there is a teflon gasket there but surface irregularities and the amount of torque applied during in-place repair is sometimes not enough.
Skål,

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Postby Alex G on Wed Dec 24, 2008 12:09 am

Hi again Eric (and fellow HBers)

Well I scored a great deal on a multimeter after work today - $20 for a digital meter with 19 ranges complete with pliers, wire strippers/snippers and a case!

Here are my findings:
Heating element voltage from either terminal to ground is 1.4v
Thermostat voltage from either terminal to ground is 1.4v

I thought I should expect 0 or 110v ish, so I wondered if I had set my meter incorrectly, but I don't think so (it was set to the 200v AC voltage range). I snooped around a bit more inside to find any old connector which gave me a 110v reading - when I tried the top connector on the XP110, I did in fact get about 110v... 116.5V to be exact, so I think the new meter's fine.

I even disconnected the power and removed the leads from the heating element and checked resistance across the terminals. I got 11.3 Ohms. Does this indicated that the element is working OK?

As you can imagine, I'm still puzzled but I know there are so many very knowledgeable people here - I welcome any advise or suggestions you can throw at me!
Thanks in advance.
Alex.
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Postby erics on Wed Dec 24, 2008 12:54 am

The top connection on the pstat is the "common" terminal (1) and it is supposed to have line voltage - so that's good. Next down is the normally open (NO) terminal and it has power when the pstat is satisfied. The bottom terminal is the normally closed (NC) terminal and it has power when the pstat is trying to power the heating element.

So, when the machine is acting up (boiler pressure going way down), the NC terminal on the pstat should read line voltage because the pstat mechanism electrically connects the common and NC terminals. On your Izzo Alex, one of the wires from the bottom terminal powers the red light and the other wire goes to a connection you will tell us about. Naturally, trace this wire with the power off and the machine unplugged.

On some machines this wire is used to power a separate mechanical relay which, in turn, sends power to the element. On others it switches a solid state relay which sends power to the element. In some cases, the mechanical relay is part of the GICAR controller.
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Postby mhoy on Wed Dec 24, 2008 4:23 pm

Seems like your heating element is OK.

While unplugged from AC power, check that the thermal safety switch has zero resistance.

Mark
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Postby Alex G on Wed Dec 24, 2008 8:21 pm

AHA!!! I think I've figured it out!

I was reading on another site about a fellow with similar problems with his Magister MS-40. His service guy suggested an interesting test... bang on the power relay with your knuckle! If it is a mechanical relay that has begun to fail, this may shake it into it's circuit closed state, even if for a couple of seconds before 're-failing'. Well, I thought, this is an easy test so I tried it. VOILA! With a voltmeter handy I turned on the machine and just to be thorough, I retested heating element to ground. 0 volts, as expected. Then I gave the power relay a jiggle and *CLICK* I heard the mechanism inside cycle (first time since the machine went cold, now that I think of it). Retested voltage at the heating element. 115 volts, woo hoo! Then I heard a very quiet click inside the relay, retested voltage at the element - back to 0 volts. Repeated this test three or four times - same result: loud click, 115v power for a couple of seconds, quiet click, power failure.

Does this sound to you guys like I've isolated the problem?
If so, can I replace this unit with a SSR relay? I hear they are far more reliable.
If a SSR is OK, can you recommend a good/appropriate one for this machine?

I've included a couple more pics of the relay in my Alex. It is a Finder 66.82.8.110.0307. I looked for this on the Finder manufacturer's page but although this model showed up, it said "no specs found" so I'm not sure what is required. Again as always, I respect you guys' experience and knowledge and value your input. Two days ago I didn't know what a power relay was... the internet's a cool tool, huh?

Thanks again
Alex.

Here's a couple pics
(the bottom pic was taken after removing all the connectors and flipping the relay over):ImageImage
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Postby erics on Wed Dec 24, 2008 9:58 pm

Is an SSR more reliable - yes - certainly it has a far greater life expectancy. BTW, I found this on Finder relays: http://www.findernet.com/comuni/pdf/S66EN.pdf

I would advise that you simply plan on replacing the bad part with an equal from your local Alex Izzo dealer. Replacing this with an SSR is possible but not really for someone who just learned about power relays. :)

The control end of that relay has the one terminal with 2 blues and 1 white. The one white wire likely would come from the bottom pstat terminal. So, when the machine is in its failed state, the bottom terminal of the pstat should still have voltage as well as the one white terminal on the Finder relay.

Something appears to be causing the coil inside the relay to lose power. It is hopefully a faulty coil and a replacement relay would solve the problem but it doesn't hurt to do a little more digging.
Skål,

Eric S.
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