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Date: 26 Feb 2007 21:38:51
From: Ken Fox
Subject: A potentially Useful Autofill Observation
This is the second time I've made this observation; the first time I didn't
trust it and it was maybe 1.5 years ago. I don't know how generalizable
this will be but I throw it out as I think the likelihood is that it IS
generalizable across different espresso machines with autofill.

The last few days my frothing has been subpar, not horrible, but subpar, and
the milk separated within a minute or so of making a morning cappa, with no
change in the milk or in my technique.

The culprit is mineral deposition on the autofill probe, which will happen
preferentially at the boiler waterline. As a result, the probe loses its
electrical conductivity at that point and the boiler refills to a slightly
higher level. This continues over time until the boiler fill level
necessary to have the probe shut off autofill function is so high that the
steam coming out the steam wand is TOO MOIST.

What I noticed this morning was that even after blowing off the steam wand,
I had very wet steam continuing to come out; I noticed that yesterday but
today it was even more obvious. Presumably, moist steam and injection of
water along with it does not improve microfoaming:-)

The "cure" is to remove the autofill probe and to use sandpaper or some
other abrasive on it, to clear off the nonconducting minerals, then to
replace the probe at a level that works in your machine.

For those who think that they are using boiler safe water and that this
prevents this problem, think again. My house has a whole house softener and
the cation softened water my machine uses reads "0" grains per gallon on
reliable test strips. But there are enough minerals of whatever sort left
that over time, a year or two in my case, the probe does get coated and
needs to be cleaned off.

So, if you notice that your frothing results are going downhill, and
especially that even after purging the steam wand that you get wet steam
mixed with water, this may be your cue on an autofill machine that 5 minutes
maintenance on the autofill probe is in order.

ken






 
Date: 27 Feb 2007 08:58:11
From: daveb
Subject: Re: A potentially useful autofill observation of electrolysis
On Feb 27, 1:01 am, "Craig Andrews" <alt.cof...@deletethis.rogers.com >
wrote:
> "Robert Harmon" <r_h_har...@Zhotmail.com> wrote in message
>
> news:0DPEh.6354$_73.5188@newsread2.news.pas.earthlink.net...
>
> > Howdy Ken!
> > Q) What happens when two (or more) dissimilar metals are immersed in
> > water?
>
> Electrolysis.
> Craig.
>

such as what occurs in Gaggia boilers = brass + Aluminum



 
Date: 27 Feb 2007 08:56:20
From: daveb
Subject: Re: A potentially Useful Autofill Observation

>
> I personally hate autofill and regard it as being useless, like tits on a
> bull, on machines used in a home. But obviously I'm not your typical user
> and sight glasses have all but disappeared. The biggest problem is that
> with autofill and no sightglass, there is no way to know how much water is
> in the boiler, so you have to infer the level from the machine's behavior.
>
> I do not have your guts, and pulling an autofill probe out of a pressurized
> boiler is definitely not within my competency level:-)
>
> ken

Autofill is essential to protect the heating element from self-
destruction.

It is not a pain in the ass, but vital to every boiler that produces
steam -- large or small.

Humans are NOT reliable 'level controllers' -- too boring.

Dave
Saeco / Gaggia service SE



 
Date: 27 Feb 2007 07:11:49
From: Danny
Subject: Re: A potentially Useful Autofill Observation
Ken Fox wrote:
> This is the second time I've made this observation; the first time I didn't
> trust it and it was maybe 1.5 years ago. I don't know how generalizable
> this will be but I throw it out as I think the likelihood is that it IS
> generalizable across different espresso machines with autofill.
>
> The last few days my frothing has been subpar, not horrible, but subpar, and
> the milk separated within a minute or so of making a morning cappa, with no
> change in the milk or in my technique.
>
> The culprit is mineral deposition on the autofill probe, which will happen
> preferentially at the boiler waterline. As a result, the probe loses its
> electrical conductivity at that point and the boiler refills to a slightly
> higher level. This continues over time until the boiler fill level
> necessary to have the probe shut off autofill function is so high that the
> steam coming out the steam wand is TOO MOIST.
>
> What I noticed this morning was that even after blowing off the steam wand,
> I had very wet steam continuing to come out; I noticed that yesterday but
> today it was even more obvious. Presumably, moist steam and injection of
> water along with it does not improve microfoaming:-)
>
> The "cure" is to remove the autofill probe and to use sandpaper or some
> other abrasive on it, to clear off the nonconducting minerals, then to
> replace the probe at a level that works in your machine.
>
> For those who think that they are using boiler safe water and that this
> prevents this problem, think again. My house has a whole house softener and
> the cation softened water my machine uses reads "0" grains per gallon on
> reliable test strips. But there are enough minerals of whatever sort left
> that over time, a year or two in my case, the probe does get coated and
> needs to be cleaned off.
>
> So, if you notice that your frothing results are going downhill, and
> especially that even after purging the steam wand that you get wet steam
> mixed with water, this may be your cue on an autofill machine that 5 minutes
> maintenance on the autofill probe is in order.
>
> ken
>
>

I've always known this, probably because the autofill probe on my
machines is in a sight glass and very visible. You can even see the
discolouration at the tip. As you note, on most machines it is a 5
minute task to remove the probe and clean it. Just make sure the
machine isn't at pressure- I once succesfully removed, cleaned and
reinserted the autofill probe whilst the machine was running and in
use. It had stopped working during the day, and since I'd changed the
autofill electronics I was confident it wasn't the black box. It
looked like there was a bubble or some other strangeness causing the
water to stay in contact with the probe although the level was getting
lower, even stranger since the probe is located in a glass tube so
isn't conductive, of course. I was able to press a cloth in the
orifice whilst my assistant cleaned the probe and then had to
carefully and firmly replace it whilst steam escaped :)

--
Regards, Danny

http://www.gaggia-espresso.com (a purely hobby site)



  
Date: 27 Feb 2007 00:31:54
From: Ken Fox
Subject: Re: A potentially Useful Autofill Observation
"Danny" <danny@nospam.gaggia-espresso.com > wrote in message
news:54i3s2F1vpsq0U1@mid.individual.net...
> >>
>
> I've always known this, probably because the autofill probe on my machines
> is in a sight glass and very visible. You can even see the discolouration
> at the tip. As you note, on most machines it is a 5 minute task to remove
> the probe and clean it. Just make sure the machine isn't at pressure- I
> once succesfully removed, cleaned and reinserted the autofill probe whilst
> the machine was running and in use. It had stopped working during the day,
> and since I'd changed the autofill electronics I was confident it wasn't
> the black box. It looked like there was a bubble or some other
> strangeness causing the water to stay in contact with the probe although
> the level was getting lower, even stranger since the probe is located in a
> glass tube so isn't conductive, of course. I was able to press a cloth in
> the orifice whilst my assistant cleaned the probe and then had to
> carefully and firmly replace it whilst steam escaped :)
>
> --
> Regards, Danny
>
> http://www.gaggia-espresso.com (a purely hobby site)
>

Hi Danny,

I personally hate autofill and regard it as being useless, like tits on a
bull, on machines used in a home. But obviously I'm not your typical user
and sight glasses have all but disappeared. The biggest problem is that
with autofill and no sightglass, there is no way to know how much water is
in the boiler, so you have to infer the level from the machine's behavior.

I do not have your guts, and pulling an autofill probe out of a pressurized
boiler is definitely not within my competency level:-)

ken




 
Date: 27 Feb 2007 05:48:44
From: Robert Harmon
Subject: Re: A potentially Useful Autofill Observation
Howdy Ken!
Q) What happens when two (or more) dissimilar metals are immersed in water?
A) Corrosion (metal oxides)
Q) What happens to the metals oxides created? A) They are suspended in
solution.
Q) What happens to suspended metal oxides? A) Some are passed in solution &
others adhere to other metals.

So, even though you're filtering & treating your house water, what is
happening inside the boiler is undoing your efforts. Ideally the boiler
would be made of only one metal and/or ceramic type. Count what's actually
in my Bunn. Copper boiler, S/S auto fill probe & other fittings, iron
heating element, and I'll bet there's even some aluminum hidden somewhere in
there. Hell, calling this thing a boiler is only partly correct; it's also a
pretty good electroplating tank.
--
Robert (It's been a while since I last reviewed this topic, so don't bet the
farm on the above.) Harmon
http://tinyurl.com/pou2y
http://tinyurl.com/psfob
http://tinyurl.com/fkd6r

"Ken Fox" <morceaudemerdeThisMerdeGoes@hotmail.com > wrote in message
news:54hqujF20ph7bU1@mid.individual.net...
> This is the second time I've made this observation; the first time I
> didn't trust it and it was maybe 1.5 years ago. I don't know how
> generalizable this will be but I throw it out as I think the likelihood is
> that it IS generalizable across different espresso machines with autofill.
>
> The last few days my frothing has been subpar, not horrible, but subpar,
> and the milk separated within a minute or so of making a morning cappa,
> with no change in the milk or in my technique.
>
> The culprit is mineral deposition on the autofill probe, which will happen
> preferentially at the boiler waterline. As a result, the probe loses its
> electrical conductivity at that point and the boiler refills to a slightly
> higher level. This continues over time until the boiler fill level
> necessary to have the probe shut off autofill function is so high that the
> steam coming out the steam wand is TOO MOIST.
>
> What I noticed this morning was that even after blowing off the steam
> wand, I had very wet steam continuing to come out; I noticed that
> yesterday but today it was even more obvious. Presumably, moist steam and
> injection of water along with it does not improve microfoaming:-)
>
> The "cure" is to remove the autofill probe and to use sandpaper or some
> other abrasive on it, to clear off the nonconducting minerals, then to
> replace the probe at a level that works in your machine.
>
> For those who think that they are using boiler safe water and that this
> prevents this problem, think again. My house has a whole house softener
> and the cation softened water my machine uses reads "0" grains per gallon
> on reliable test strips. But there are enough minerals of whatever sort
> left that over time, a year or two in my case, the probe does get coated
> and needs to be cleaned off.
>
> So, if you notice that your frothing results are going downhill, and
> especially that even after purging the steam wand that you get wet steam
> mixed with water, this may be your cue on an autofill machine that 5
> minutes maintenance on the autofill probe is in order.
>
> ken
>
>




  
Date: 27 Feb 2007 01:01:53
From: Craig Andrews
Subject: Re: A potentially Useful Autofill Observation

"Robert Harmon" <r_h_harmon@Zhotmail.com > wrote in message
news:0DPEh.6354$_73.5188@newsread2.news.pas.earthlink.net...
> Howdy Ken!
> Q) What happens when two (or more) dissimilar metals are immersed in
> water?

Electrolysis.
Craig.

> A) Corrosion (metal oxides)
> Q) What happens to the metals oxides created? A) They are suspended in
> solution.
> Q) What happens to suspended metal oxides? A) Some are passed in
> solution & others adhere to other metals.
>
> So, even though you're filtering & treating your house water, what is
> happening inside the boiler is undoing your efforts. Ideally the
> boiler would be made of only one metal and/or ceramic type. Count
> what's actually in my Bunn. Copper boiler, S/S auto fill probe & other
> fittings, iron heating element, and I'll bet there's even some
> aluminum hidden somewhere in there. Hell, calling this thing a boiler
> is only partly correct; it's also a pretty good electroplating tank.
> --
> Robert (It's been a while since I last reviewed this topic, so don't
> bet the farm on the above.) Harmon
> http://tinyurl.com/pou2y
> http://tinyurl.com/psfob
> http://tinyurl.com/fkd6r
>
> "Ken Fox" <morceaudemerdeThisMerdeGoes@hotmail.com> wrote in message
> news:54hqujF20ph7bU1@mid.individual.net...
>> This is the second time I've made this observation; the first time I
>> didn't trust it and it was maybe 1.5 years ago. I don't know how
>> generalizable this will be but I throw it out as I think the
>> likelihood is that it IS generalizable across different espresso
>> machines with autofill.
>>
>> The last few days my frothing has been subpar, not horrible, but
>> subpar, and the milk separated within a minute or so of making a
>> morning cappa, with no change in the milk or in my technique.
>>
>> The culprit is mineral deposition on the autofill probe, which will
>> happen preferentially at the boiler waterline. As a result, the
>> probe loses its electrical conductivity at that point and the boiler
>> refills to a slightly higher level. This continues over time until
>> the boiler fill level necessary to have the probe shut off autofill
>> function is so high that the steam coming out the steam wand is TOO
>> MOIST.
>>
>> What I noticed this morning was that even after blowing off the steam
>> wand, I had very wet steam continuing to come out; I noticed that
>> yesterday but today it was even more obvious. Presumably, moist
>> steam and injection of water along with it does not improve
>> microfoaming:-)
>>
>> The "cure" is to remove the autofill probe and to use sandpaper or
>> some other abrasive on it, to clear off the nonconducting minerals,
>> then to replace the probe at a level that works in your machine.
>>
>> For those who think that they are using boiler safe water and that
>> this prevents this problem, think again. My house has a whole house
>> softener and the cation softened water my machine uses reads "0"
>> grains per gallon on reliable test strips. But there are enough
>> minerals of whatever sort left that over time, a year or two in my
>> case, the probe does get coated and needs to be cleaned off.
>>
>> So, if you notice that your frothing results are going downhill, and
>> especially that even after purging the steam wand that you get wet
>> steam mixed with water, this may be your cue on an autofill machine
>> that 5 minutes maintenance on the autofill probe is in order.
>>
>> ken
>>
>>
>
>



   
Date: 27 Feb 2007 06:24:04
From: Robert Harmon
Subject: Re: A potentially Useful Autofill Observation
Give the man an 'A' for the correct answer & then give him 5 demerits for
showing the ol' teacher up!
--
Robert (Why dumb down tests; exercise, especially the mental kind, is good
for young people!) Harmon
http://tinyurl.com/pou2y
http://tinyurl.com/psfob
http://tinyurl.com/fkd6r

"Craig Andrews" <alt.coffee@deletethis.rogers.com > wrote in message
news:54hvqjF20h2qhU1@mid.individual.net...
>
> "Robert Harmon" <r_h_harmon@Zhotmail.com> wrote in message
> news:0DPEh.6354$_73.5188@newsread2.news.pas.earthlink.net...
>> Howdy Ken!
>> Q) What happens when two (or more) dissimilar metals are immersed in
>> water?
>
> Electrolysis.
> Craig.
>
>> A) Corrosion (metal oxides)
>> Q) What happens to the metals oxides created? A) They are suspended in
>> solution.
>> Q) What happens to suspended metal oxides? A) Some are passed in solution
>> & others adhere to other metals.
>>
>> So, even though you're filtering & treating your house water, what is
>> happening inside the boiler is undoing your efforts. Ideally the boiler
>> would be made of only one metal and/or ceramic type. Count what's
>> actually in my Bunn. Copper boiler, S/S auto fill probe & other fittings,
>> iron heating element, and I'll bet there's even some aluminum hidden
>> somewhere in there. Hell, calling this thing a boiler is only partly
>> correct; it's also a pretty good electroplating tank.
>> --
>> Robert (It's been a while since I last reviewed this topic, so don't bet
>> the farm on the above.) Harmon
>> http://tinyurl.com/pou2y
>> http://tinyurl.com/psfob
>> http://tinyurl.com/fkd6r
>>
>> "Ken Fox" <morceaudemerdeThisMerdeGoes@hotmail.com> wrote in message
>> news:54hqujF20ph7bU1@mid.individual.net...
>>> This is the second time I've made this observation; the first time I
>>> didn't trust it and it was maybe 1.5 years ago. I don't know how
>>> generalizable this will be but I throw it out as I think the likelihood
>>> is that it IS generalizable across different espresso machines with
>>> autofill.
>>>
>>> The last few days my frothing has been subpar, not horrible, but subpar,
>>> and the milk separated within a minute or so of making a morning cappa,
>>> with no change in the milk or in my technique.
>>>
>>> The culprit is mineral deposition on the autofill probe, which will
>>> happen preferentially at the boiler waterline. As a result, the probe
>>> loses its electrical conductivity at that point and the boiler refills
>>> to a slightly higher level. This continues over time until the boiler
>>> fill level necessary to have the probe shut off autofill function is so
>>> high that the steam coming out the steam wand is TOO MOIST.
>>>
>>> What I noticed this morning was that even after blowing off the steam
>>> wand, I had very wet steam continuing to come out; I noticed that
>>> yesterday but today it was even more obvious. Presumably, moist steam
>>> and injection of water along with it does not improve microfoaming:-)
>>>
>>> The "cure" is to remove the autofill probe and to use sandpaper or some
>>> other abrasive on it, to clear off the nonconducting minerals, then to
>>> replace the probe at a level that works in your machine.
>>>
>>> For those who think that they are using boiler safe water and that this
>>> prevents this problem, think again. My house has a whole house softener
>>> and the cation softened water my machine uses reads "0" grains per
>>> gallon on reliable test strips. But there are enough minerals of
>>> whatever sort left that over time, a year or two in my case, the probe
>>> does get coated and needs to be cleaned off.
>>>
>>> So, if you notice that your frothing results are going downhill, and
>>> especially that even after purging the steam wand that you get wet steam
>>> mixed with water, this may be your cue on an autofill machine that 5
>>> minutes maintenance on the autofill probe is in order.
>>>
>>> ken
>>>
>>>
>>
>>
>