HomeRoast Digest


Topic: Auto-fill won't shut off (17 msgs / 648 lines)
1) From: Mike Chester
This is a multi-part message in MIME format.
I sent this question to the group yesterday and it apparently got lost =
in the either as I never got a copy back and no one posted and answer.  =
I am just going to paste my old email below.  If the original shows up, =
I am sorry for the duplication. 
Mike
This afternoon, I used some water from the hot water tap on my Vetrano =
to warm up my demi before pulling a ristretto of SO Brazil Yellow =
Bourbon.  After I finished pulling the shot, the pump kicked on to =
refill the boiler and it shut off normally.  A few seconds later, the =
pump came back on and pushed water through the full boiler and out the =
OPV into the drip tray.  It turned on and off a few times more before =
staying on.  I had to turn off the master switch to stop it.  =
Fortunately this happened while I was standing there so I could stop it =
before it made too much of a mess.  I let the machine cool down, but it =
did not make a difference.  When I turn on the master switch, the pump =
starts.  I figure that the problem is the fill switch on the boiler is =
saying that the boiler needs water all the time.  Does anyone here know =
how that switch senses a low water condition?  Knowing how it works =
could help me figure out if it can be fixed or adjusted, or if I have to =
order a new switch.  
BTW - the ristretto was excellent.  
Tomorrow will be rough.  I will have to make drip coffee.  I have only =
drank espresso based coffees for the last three months.  In another =
recent thread it was asked if espresso drinkers drank other types of =
coffee.  I was going to respond, but had not as yet.  You can put me =
with the group that says that the pressure extraction method gets the =
best out of the coffee beans.  For "regular" coffee, I make only =
Americanos.  Hopefully, the problem can be easily fixed.
Mike Chester  

2) From: Brett Mason
The pressurestat may be your culprit... its job is to sense low water
by means of pressure, and then tell the pump to correct the
situation...
If I recall correctly...
Brett
On 1/5/07, Mike Chester  wrote:
<Snip>
-- 
Cheers,
Bretthttp://homeroast.freeservers.com

3) From: miKe mcKoffee
That is a negative. Pstat controls boiler pressure not boiler fill level.
Fill level is controlled by separate auto-fill sensor in boiler. May be a
loose intermittent connection to the auto-fill sensor. On my Bric' when
sensor wire disconnected (circuit broken) auto-fill in continuous (technique
used for over filling when descaling)
If you are using distilled water in the boiler that can be the problem,
sensor works by conducting while in water. As boiler water level lowers the
circuit is broken inducing auto-fill. Not enough disolved solids in the
water and electricity can no flow in the circuit.
Get on the phone with Chris' tech staff ASAP, they be very good to work
with.
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.
<Snip>

4) From: Michael Dhabolt
Sorry Brett, but....
The pressurestat controls the heaters.....boiler pressure is directly
related to water temperature in the boiler, so the pressurestat is actually
controlling the temperature of the water in the boiler by sensing
pressure.   I know......it's awfully early.
Mike,
The water level is controlled by the auto-fill probe.  I'm not familiar with
the Vetrano - so some interpretation of the following may be necessary.
Remove a little body work so you can inspect the boiler (top...may be on the
upper portion of the ends).  You'll find a boiler penetration with an
auto-fill sensor fitting (usually a gland similar to a compression joint)
that has a small tube - usually white nylon or teflon or other insulator
with a single rod sticking through the tube - the rod is somewhere around 12
/ 10 gauge.  There will be a single wire hooked to the rod and the wire will
go to the autofill/pump control box.  This will be the only single wire
connection to the boiler.  The rod extends thru the fitting and into the
boiler.....when the water level increases to the point where it touches the
rod (inside the boiler)......it should turn off the pump.  Your problem
could be a poor connection at the wire where it hooks to the rod (unhook and
rehook the wire to the probe) , or a poor connection somewhere else in that
circuit (follow the wire).  Mark the rod so you can remember how far into
the boiler it should extend, and move it into and out of the boiler a
little, leaving it in the original position....that may help.  Trouble with
the circuitry at the other end of the wire is not unheard of.  When the
auto-fill is operating correctly - removing and replacing the wire to the
auto-fill probe should result in the pump running (wire unhooked) and
stopping (wire hooked to probe - boiler full to the right level - or touched
to ground), it commonly takes a second or two for the circuitry to be
convinced that the open or closed signal is not just a wave in the boiler.
You mentioned that you thought the water was going to the drip tray from the
OPV.  If that is where it is coming from (rather than from an over-full
boiler), it is a different problem.  I believe the Vetrano is a lever
operated E61.  The OPV will relieve water to the drip tray when it sees
water pressure too high at the discharge of the pump.  If operating
correctly this will relieve water to the drip tray at brew pressure, or with
a rotary pump the pressure is usually set at 9 Bar by adjusting the bypass
at the pump and the OPV is set a little higher.  The lever on the group
operates a microswitch (as well as valves internal to the group).  This
microswitch controls the pump when pulling a shot.  If the switch fails and
maintains contact (closed circuit to the pump) when the lever is not in the
correct position to pull a shot, the pump will keep running.  It is not
uncommon to see the microswitch loose, adjusted incorrectly or held in the
closed position by something adrift and not allowing it to operate
correctly.  You can check the microswitch by removing one of the wires.  If
you determine it is the microswitch.....it's a pretty standard
configuration.....available locally at electronics stores.
Mike (just plain)

5) From: Brett Mason
I would submit that my quick explanation did indeed lead to the
correct answer...  Thanks, Mike & Mike, for the clarification!
When my Silvia overfilled, it was an operator error...
Brett
On 1/5/07, Michael Dhabolt  wrote:
<Snip>
-- 
Cheers,
Bretthttp://homeroast.freeservers.com

6) From: Mike Chester
This is a multi-part message in MIME format.
Thanks miKe and Mike.  Your suggestions were excellent.  When I remove =
the probe wire and ground it, the pump stops.  This tells me that the =
probe is at fault.  I just spoke with the service department at Chris' =
and they agree with me and are sending me a new probe.  In the meantime, =
I will try removing and cleaning the old one.  It is a very tight =
squeeze in there and I have to find some thin wall sockets to remove it, =
but I need to do that in order to replace it anyway.  The service tech I =
spoke with was very nice and even apologized for my having to do without =
espresso for the weekend.  I guess that they are used to dealing with us =
nutz.  
Mike Chester

7) From: Michael Dhabolt
Mike,
Try twisting and pushing the probe in a little and withdrawing it a little,
then hook it back up and see what happens.  Frequently that will do it.  You
are using water with a little conductivity?  Right?  Straight RO water
frequently will not have enough conductivity to complete the circuit.
Mike (just plain)

8) From: Mike Chester
This is a multi-part message in MIME format.
So far, I have only been able to loosen the top probe nut which allows =
me to twist it and move it up and down about 1/4 inch.  This has not =
helped.  I need to buy a short open end wrench or an extra thin wall =
socket to remove the next nut.  I am not using RO water.  I have well =
water that goes through a softener and then a 3 stage cartridge filter =
before going to the machine.  The tech asked me the same question, but =
said since it had worked properly for 5 months, the water was probably =
not the problem.  I wonder why they use that method.  It seems that a =
simple float switch would work fine, though I am not sure what a =
pressurized atmosphere would do to a float switch.  It probably wouldn't =
work correctly, so I guess that I just answered my own question.  
Well, I am off to the tool store now.
Mike

9) From: Michael Dhabolt
Mike,
On 1/5/07, Mike Chester  wrote:
<Snip>
Actually.....,  La Cimbali used to use a float setup on their older lever
machines.  The float inside the boiler moved a magnet on the boiler side of
a thin SS membrane, the switch and it's operating linkages were on the
outside of the membrane. Expensive, complicated, trouble prone (I've heard).
Are you sure the boiler fill solenoid valve is operating?  Does the pressure
gauge go up to approx. brew pressure when the pump is running in boiler fill
mode (manipulating the auto-fill probe wire)?
There isn't much that can go wrong with the level sensor.  If the valve
isn't opening, the boiler water would never reach the necessary level to
touch the probe and turn the pump off.....The symptoms would be - what you
are seeing.  You should hear a fairly loud 'clunk' from the valve if you
remove a wire from it when the machine is trying to fill the boiler.  If you
can hear the valve operate.....it isn't confirmation that you are getting
flow through it......but if you can't hear it......that may be your trouble
(you can replace just the coil if that's the problem and the valve itself is
OK).  Is there anything else in the plumbing between the pump and the boiler
fill penetration that could be bonkers and obstructing flow?
Mike (just plain)

10) From: miKe mcKoffee
This is a multi-part message in MIME format.
Another test if the boiler fill mode is actually filling the boiler (can be
done with cold boiler) is open the steam wand, remove auto-fill sensor wire
to engage auto-fill and turn on machine (if necessary since stuck on seems
to be the symptom). Boiler should over fill and have water flow out open
steam wand. NOTE: water will also quite probably flow out vacuum breaker
valve unless you hold the pin up/closed. (Same boiler over fill technique
used to preventative descale the boiler.)
 
miKe  
From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of Michael Dhabolt
Sent: Friday, January 05, 2007 12:43 PM
To: homeroast
Subject: Re: +Auto-fill won't shut off
Mike,
On 1/5/07, Mike Chester  wrote: 
It seems that a simple float switch would work fine, though I am not sure
what a pressurized atmosphere would do to a float switch.
Actually.....,  La Cimbali used to use a float setup on their older lever
machines.  The float inside the boiler moved a magnet on the boiler side of
a thin SS membrane, the switch and it's operating linkages were on the
outside of the membrane. Expensive, complicated, trouble prone (I've heard).
Are you sure the boiler fill solenoid valve is operating?  Does the pressure
gauge go up to approx. brew pressure when the pump is running in boiler fill
mode (manipulating the auto-fill probe wire)?
 
There isn't much that can go wrong with the level sensor.  If the valve
isn't opening, the boiler water would never reach the necessary level to
touch the probe and turn the pump off.....The symptoms would be - what you
are seeing.  You should hear a fairly loud 'clunk' from the valve if you
remove a wire from it when the machine is trying to fill the boiler.  If you
can hear the valve operate.....it isn't confirmation that you are getting
flow through it......but if you can't hear it......that may be your trouble
(you can replace just the coil if that's the problem and the valve itself is
OK).  Is there anything else in the plumbing between the pump and the boiler
fill penetration that could be bonkers and obstructing flow? 
 
Mike (just plain)

11) From: miKe mcKoffee
This is a multi-part message in MIME format.
Cautionary addition! With over filled boiler when turning on machine have
hot water wand open. Excess water will flow out the hot water wand as boiler
builds pressure until enough water emptied for auto-fill kicking in bringing
it back to proper filled level. Close the hot water wand when auto-fill
kicks on. You'll also want to hold the vac' breaker pin up (with needle nose
plyers not fingers) or water will flow out while coming up to pressure
needed to push the pin closed.
 
All assuming auto-fill always on problem resolved of course!
 
miKe  
From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of miKe mcKoffee
Sent: Friday, January 05, 2007 1:12 PM
To: homeroast
Subject: RE: +Auto-fill won't shut off
Another test if the boiler fill mode is actually filling the boiler (can be
done with cold boiler) is open the steam wand, remove auto-fill sensor wire
to engage auto-fill and turn on machine (if necessary since stuck on seems
to be the symptom). Boiler should over fill and have water flow out open
steam wand. NOTE: water will also quite probably flow out vacuum breaker
valve unless you hold the pin up/closed. (Same boiler over fill technique
used to preventative descale the boiler.)
 
miKe  
From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of Michael Dhabolt
Sent: Friday, January 05, 2007 12:43 PM
To: homeroast
Subject: Re: +Auto-fill won't shut off
Mike,
On 1/5/07, Mike Chester  wrote: 
It seems that a simple float switch would work fine, though I am not sure
what a pressurized atmosphere would do to a float switch.
Actually.....,  La Cimbali used to use a float setup on their older lever
machines.  The float inside the boiler moved a magnet on the boiler side of
a thin SS membrane, the switch and it's operating linkages were on the
outside of the membrane. Expensive, complicated, trouble prone (I've heard).
Are you sure the boiler fill solenoid valve is operating?  Does the pressure
gauge go up to approx. brew pressure when the pump is running in boiler fill
mode (manipulating the auto-fill probe wire)?
 
There isn't much that can go wrong with the level sensor.  If the valve
isn't opening, the boiler water would never reach the necessary level to
touch the probe and turn the pump off.....The symptoms would be - what you
are seeing.  You should hear a fairly loud 'clunk' from the valve if you
remove a wire from it when the machine is trying to fill the boiler.  If you
can hear the valve operate.....it isn't confirmation that you are getting
flow through it......but if you can't hear it......that may be your trouble
(you can replace just the coil if that's the problem and the valve itself is
OK).  Is there anything else in the plumbing between the pump and the boiler
fill penetration that could be bonkers and obstructing flow? 
 
Mike (just plain)

12) From: Michael Dhabolt
Another Cautionary Note.  (Maybe we should write a book)
When filling the boiler to solid status  (water comes out of Vacuum Breaker
and Hot Water wand),  Be sure that the water valve is all the way open.
Watch the boiler pressure and be quick to pull the plug if it gets much
above 2 Bar.
The pump is fully capable of over pressurizing the boiler - - When pumping
to a solid system (un-vented) the pump will go to it's 9 Bar (~= 135psi)
output pressure.  The HX loop portion of the boiler is designed to deal with
that - - the steam side (the shell itself) is not.  The steam side relief
valve scares the beejesus out of you when it pops unexpectedly
(usually 2.8Bar or so), if it fails.....new boiler time.
Mike (just plain)

13) From: miKe mcKoffee
This is a multi-part message in MIME format.
Ok, playing "editor" rather than writer here. First paragraph first sentence
in paren's replace "hot water" with "steam" wand. And again second sentence.
Reason: Under normal operating conditions the water wand outlet is already
below water level in the tank and water is pushed out by steam pressure.
When over filling the boiler on an HX machine, which can be done hot or
cold, you are over filling by forcing water out the "steam" wand which is
above the normal water level in the top steam area of the boiler. The normal
steam area of the boiler is being over filled with water.
 
NOTE: Personally I'm chicken and when re-heating after descaling and over
filling boiler. I don't let boiler pressure go above 1.5bar! (I've been told
by a couple techs that the Safety Over Pressure Valve once popped often
won't reseat properly and must be replaced so run over filled boiler heating
well below anticipated threshold.) Now definitely have the "water" wand
fully opened until first normal auto-fill kicks in. As boiler starts to heat
and as soon as boiler pressure begins to build water will immediately start
flowing out the "water wand".  
 
miKe  
From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of Michael Dhabolt
Sent: Friday, January 05, 2007 4:29 PM
Another Cautionary Note.  (Maybe we should write a book)
 
When filling the boiler to solid status  (water comes out of Vacuum Breaker
and Hot Water wand),  Be sure that the water valve is all the way open.
Watch the boiler pressure and be quick to pull the plug if it gets much
above 2 Bar. 
 
The pump is fully capable of over pressurizing the boiler - - When pumping
to a solid system (un-vented) the pump will go to it's 9 Bar (~= 135psi)
output pressure.  The HX loop portion of the boiler is designed to deal with
that - - the steam side (the shell itself) is not.  The steam side relief
valve scares the beejesus out of you when it pops unexpectedly (usually 2.8
Bar or so), if it fails.....new boiler time.
 
Mike (just plain)

14) From: Michael Dhabolt
miKe,
Correct on all counts.  Time for a nap, not to be trusted with keyboard.
Mike (just plain)
On 1/5/07, miKe mcKoffee  wrote:
<Snip>

15) From: Mike Chester
This is a multi-part message in MIME format.
I turns out you guys were right.  The sensor was working correctly, but =
the boiler fill valve was not letting water into the boiler.  After I =
got home from dinner last night, I ready both Mikes emails about opening =
the steam wand to see if water flowed out when the pump was on.  I =
disconnected the heater circuit, so I could perform this test cool.  =
Nothing came out.  I turned the coil on the fill valve slightly and =
checked the electrical connections and tried it again after about 30 =
seconds water began flowing out of the steam wand.  A few seconds later =
I got a spray of water out of the vacuum breaker which hit some wiring =
and tripped the GFCI and shut the power off.  I did not realize that is =
what happened.  I thought that the safety relief had blown and had shut =
off the power.  I looked all over the boiler for the "reset" but could =
not find it.  I had a couple of beers with dinner and was tired so I =
probably should not have been working on it.  I figured I had to now =
send it back so I decided to leave it alone until today.  This morning =
when I went to grind some beans for drip coffee, the grinder would not =
run.  I then figured out that the GCFI had blown and reset it.  I hooked =
up the heater and the probe and slowly brought the machine up the =
temperature with the steam and hot water wands open.  I tried to hold =
the pin on the vacuum breaker out but it kept slipping.  It sprayed =
water a few times and tripped the GFCI a couple more times.  I turned it =
on and off to keep the pressure from rising too fast.  When the water =
coming out of the steam wand was replaced by steam, I closed that valve. =
 When steam replaced the water at the hot water wand, the pump kicked on =
and refilled the boiler.  I closed the water valve and allowed the =
boiler to come up to pressure.  I cycled the hot water to draw down the =
boiler and the auto fill properly refilled it.  I let it sit open at =
full pressure for awhile to check for leaks and then put the case back =
on and it is now ready for use.  Thanks for all of the help.  It sure =
would have helped if I had an electrical schematic and one for the =
plumbing.  I had never sat down and thought through the various =
processes of the machine.  If or when something  else goes wrong, I =
think I now have a better handle on diagnosing it.  Thanks again guys =
for pointing me in the right direction.  
Mike Chester

16) From: raymanowen
OK, Mike-
"...I now have a better handle on diagnosing it."
You're IT!
Cheers -RayO, aka Opa!

17) From: miKe mcKoffee
I assume (and hate to assume) the fix is holding. That would be a good
thing! Just curious, did you call Chris' Coffee back and discuss what
transpired and the likely root cause of the malfunction? I'd definitely keep
an eye on it for a spell and maybe force an auto-fill if leaving it on over
night or while not home. Personally to be on the safe side I'd be inclined
to have a replacement sent for the apparent offending valve since it's under
warranty.
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.
<Snip>
[mailto:homeroast-admin] On Behalf Of Mike Chester
	Sent: Saturday, January 06, 2007 2:57 PM
	
<Snip>
but the boiler fill valve was not letting water into the boiler.  After I
got home from dinner last night, I ready both Mikes emails about opening the
steam wand to see if water flowed out when the pump was on.  I disconnected
the heater circuit, so I could perform this test cool.  Nothing came out.  I
turned the coil on the fill valve slightly and checked the electrical
connections and tried it again after about 30 seconds water began flowing
out of the steam wand.  A few seconds later I got a spray of water out of
the vacuum breaker which hit some wiring and tripped the GFCI and shut the
power off.  I did not realize that is what happened.  I thought that the
safety relief had blown and had shut off the power.  I looked all over the
boiler for the "reset" but could not find it.  I had a couple of beers with
dinner and was tired so I probably should not have been working on it.  I
figured I had to now send it back so I decided to leave it alone until
today.  This morning when I went to grind some beans for drip coffee, the
grinder would not run.  I then figured out that the GCFI had blown and reset
it.  I hooked up the heater and the probe and slowly brought the machine up
the temperature with the steam and hot water wands open.  I tried to hold
the pin on the vacuum breaker out but it kept slipping.  It sprayed water a
few times and tripped the GFCI a couple more times.  I turned it on and off
to keep the pressure from rising too fast.  When the water coming out of the
steam wand was replaced by steam, I closed that valve.  When steam replaced
the water at the hot water wand, the pump kicked on and refilled the boiler.
I closed the water valve and allowed the boiler to come up to pressure.  I
cycled the hot water to draw down the boiler and the auto fill properly
refilled it.  I let it sit open at full pressure for awhile to check for
leaks and then put the case back on and it is now ready for use.  Thanks for
all of the help.  It sure would have helped if I had an electrical schematic
and one for the plumbing.  I had never sat down and thought through the
various processes of the machine.  If or when something  else goes wrong, I
think I now have a better handle on diagnosing it.  Thanks again guys for
pointing me in the right direction.  
<Snip>


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