I've asked several people about the mid-position of the lever and whether or not to use it before a pull. All have dismissed it as a worthless practice. I would like to hear if anyone manually preinfuses.

When I lift the lever on my Anita to mid-way the pump turns on but it seems a bit less noisy than normal and my pressure gauge displays pressure (seems to be equal to the blind pressure). I do understand about the gauge reading relative to the position of the T. When I lift the lever to the top I can hear the pump growl fully as it starts pumping water for a shot.

-- What exactly is happening when the lever is at mid-point?
I've looked at the diagrams dan provided, but I'd rather have it explained in simple english.

- is there any benefit to holding the lever at mid-point for any length of time? and does this time count against the total shot time?

- the sound of the pump at mid-point scares me for some reason .. makes me fear I am going to burn it out. Is this dangerous?

I've been told the machine designers count on the vibe pumps characteristic (slowly starting flow) as preinfusion .. is this correct?

If all this is covered elsewhere forgive me and direct me to it. I'd really like to understand this 'feature'? of the E-61 that nobody seems to use or discuss.


Chris

In the mid position, both the inlet out outlet valves are closed.

If the pump turns on in the mid position, the switch is misadjusted. The pump should start just as the inlet valve opens. If your gauge reads the blind pressure, the pump is pumping against the upper valve and simply cycling water thru the OPV.

The e61 pre-infuses as the valve fills.

cafeIKE wrote:In the mid position, both the inlet out outlet valves are closed.

If the pump turns on in the mid position, the switch is misadjusted. The pump should start just as the inlet valve opens. If your gauge reads the blind pressure, the pump is pumping against the upper valve and simply cycling water thru the OPV.

The e61 pre-infuses as the valve fills.

Should I be concerned about the misadjusted switch and can I adjust it myself?

On the VBM's, the E-61's midpoint lever position opens the HX and water path and allows the pressure of the heated water in the HX to be released into the brewhead and onto the coffee. I believe I have heard that referred to as a passive pre-infusion. I don't use it because the slow ramp up of pressure over the first 8 to 10 seconds that is designed into the group takes care of the preinfusion (IMO). Additionally, if you have flushed the group to bring the temperature down before pulling a shot, there is little if any built up force to deliver any significant amount of water to the coffee... IMO.

From your description, if that happened to my machine, I would assume that the switch that energizes the pump is being closed too early in the lever's arc, but I do not know how the Anita is supposed to operate— just guessing based on how my E-61 operates.

Thank you all.

I guess I won't worry about it. As long as the pump kicking in 'early' in the lever path won't do any harm. I might give Chris' a call tomorrow and talk to one of the techs about it.

Off I go to read the thread Dan provided.


Chris

erics wrote:It does no physical harm to the machine but DOES DO harm to a flushing routine because Anita's blind flow passes THROUGH the heat exchanger. See below:

I played with the lever more, if I raise it slowly I get a 'click' , no pump, at the very bottom of the mid-position. I assume this is proper operation. If I raise the lever slightly to the top of the mid-position the pump engages. It's not as out of adjustment as I first thought.

I'm confused how it would hurt my backflush. I engage the pump as normal during a backflush ... ?

Ok, I've made another discovery ..

When I pull OUT (towards me) on the lever as I lift it does not engage the switch behind the lever (pump) at the mid-point, however at this point it does NOT open the valves as it should. At this point, if I put slight sideways pressure on the lever toward the group head the valves open up and the pressure is released. Neither of these require much force at all, just slight pressure on the lever out and in at the same time.

I talked to a tech at Chris's .. he is sending me a spacer to install and he says it should fix that problem.


Chris