Flow control E61 not working?

Beginner and pro baristas share tips and tricks for making espresso.

#1: Post by Jesse.F »

I just got a QM Carola from Chris's coffee, they installed a flow control that a customer had returned, (because it was supposedly the only one they had at the time, website listed it as out of stock)

My understanding of how to calibrate it was to set it to different positions, run for 20 seconds, divide grams of water by 20 to sort out grams per second at different points on the dial. I was doing this without a portafilter, and without the boiler on (didn't see the need to work the heater) and I am not seeing any change in flow rate, even in the fully "closed" position.

Am I mistaken, and it needs the back pressure of the coffee to work?

I just wanted to double check before I hound Chris's coffee about it.

Regardless, I was to excited about my first pump machine, so I loaded up a 21g ims basket with 22g of Ethiopian Tengenge Ocholo natural roasted on 6-8, set the flow control in the "middle", PID to 205f, and pulled 45g in 29 seconds. I was very pleased with this for my first ever shot on a pump machine (only have used a Flair before)

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#2: Post by Jake_G »

You need to "calibrate" it, by removing the handle and closing the needle until the flow begins slowing down.

Some opt to allow for zero flow with the handle to the left, others prefer to have a Slayer-like low setting of 1.5 or 2ml/s, but the point is that it sounds like the flow control is too far open to do much within its range right now.

The other approach is to set a preferred high range and put the handle on facing the right and deal with whatever flow you have on the left.

For my uses, I prefer the Slayer approach with room for zero flow if needed. My machine tops about at 6ml/s, so I basically have full control from zero to 6.

Hope this helps.


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Jesse.F (original poster)

#3: Post by Jesse.F (original poster) »

What I'm saying, I can turn it one way until it stops, and water flows just as fast as when I turn it all the way to the other stop position.

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#4: Post by PIXIllate »

I would have the machine on and fully heated up for 45-60 minutes as this is the state it will be in when making coffee. Then set the knob to each 1/4 turn position starting from as closed as it can be. Measure the water over 20 seconds in ml and divide that by 20. That is the flow rate or water debit for that position. Do that for each 1/4 turn until you get to about 7-8ml/sec. That should be maximum flow on a vibe pump E61 machine.

See these threads for more information:

ECM flow control installation

A More Considered Approach to E61 Flow Control

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#5: Post by Jake_G »

Jesse.F wrote:What I'm saying, I can turn it one way until it stops, and water flows just as fast as when I turn it all the way to the other stop position.
Even after you remove the handle? It should turn about two full revolutions.

This post is relevant.
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#6: Post by Nunas »

This keeps coming up! Perhaps this explanation will make it clearer. The knob (black handle) also serves as a set screw for the ferrule into which it screws. The ferrule slides onto the shaft of the valve in a spline. Only if you loosen the knob is the ferrule free to slide up and down the spline of the shaft. So, loosen the knob, turn the control all the way closed. Before tightening the knob check to see that no or very little water flows. The needle valve is shut tight if no water comes out. Tighten the knob. You should now have a full range of adjustment from off to a torrent. The useable range is only about a turn and a quarter. More than that and the flow is too high. If you have high flow in the off position, the ferrule is bottoming out on the top of the big nut below it, preventing the needle valve from being fully closed. Okay now?

Jesse.F (original poster)

#7: Post by Jesse.F (original poster) »

I had undone the set screw (mine is an Allen set screw below the nob) I'm getting just over 1.5 turns off total travel, I'll play with it more tomorrow. I just wanted to make sure my thoughts on how it should work were correct.

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#8: Post by Nunas replying to Jesse.F »

Interesting. That's the first one I've heard of that's built like that. I've had the ECM/Profitec and the Coffee Sensor, and both were built with the handle serving double-duty as a grub screw. In any case, the remedy is the same, loosen the grub screw, turn the FC closed, check for no flow and retighten. If you get anything more than a few drops, there's something wrong. Also, as mentioned by another poster, if you don't want a zero flow setting, you can open it up a crack for a little flow and then tighten the screw.


#9: Post by KCcoffeegeek »

Greetings from another Carola Evo owner! Great machine! I have the same setup, except I bought my valve from Chris and installed it myself. I have mine set up to go all the way to 0, and with it like that I have JUST under 1.5 turns from fully closed to fully open. You should be able to see appreciable flow changes, it doesn't need coffee in the portafilter. Testing mine with no portafilter in, I get the following:

Fully open - 7.64g/second
1 full turn from closed - 5.5g/sec
1/2 turn from closed - 3g/sec

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#10: Post by walr00s »

I also have the QM FC mod from Chris'. What you're describing sounds like it is not functioning properly. If the valve is fully closed, turned completely clockwise until it won't move, there should be no flow while the pump is running. I think a lot of the advice you're getting here applies to other FC mods, where there is no set screw or the size of the paddle hinders how far you can open and close the valve. Can you remove the assembly on top of the mushroom and show us a picture of the inner parts of your needle valve?

You may need to reinstall it or at least verify the installation was done properly. I'm sure a tech at Chris' will walk you through it if you call, or you could just do it yourself using videos. When I got my machine I was hoping to wait a while to take it apart, or maybe to never take it apart, but that's just not how owning one of these things goes. I've disassembled my machine 3 times, twice to clear spilled water from wiring and once to adjust the OPV (which came stuck with loctite so that the bolt at the top of the machine could not be adjusted past a point), and disassembled my group 3 times for cleaning and lubrication in the 6 months I've had it. Just something you're going to get comfortable with. I have the group (cam, mushroom, e61 valve, and discharge spout) disassembled, cleaned, lubed and reassembled in less than 15 minutes at this point, it's not complicated.