Internals of an E61 Brew Head

Ever wonder what kind of magic ensues when you flip up the lever of your espresso machine's E61 brew head? We did, too! So we asked Bill Crossland to perform surgery on one and then walk us through the functionality.

[@SeanAlcorn]

The middle valve is actually a pre infusion valve. There is not two exhaust valves. When the pump is activated, pressure will push the middle valve down slightly (but NOT the bottom valve) opening up that middle chamber. The filling of this chamber creates a 'delay' in the buildup of the pressure. A soft 'pre infusion' or ramp up - as intended by the E61group head design

[@xbmcoholic]

Good catch Sean!

[@omaromari4038]

you probably dont care but does anyone know of a way to get back into an instagram account? I somehow forgot the login password. I appreciate any assistance you can give me

[@jeromebrendan919]

@Omar Omari instablaster =)

[@omaromari4038]

@Jerome Brendan thanks for your reply. I got to the site through google and Im waiting for the hacking stuff atm. Seems to take a while so I will reply here later with my results.

[@omaromari4038]

@Jerome Brendan it did the trick and I actually got access to my account again. I am so happy! Thanks so much you saved my account!

[@caffhuang]

After 11 years still watching. Amazing video! 👍

[@SeattleCoffeeGear]

Thanks for being a fan!

[@Django44]

So THIS is how they work. Well done everyone. I sure do miss Kat and Brendan; they both brought professionaliam, extensive know-how and a friendly sense of humor to these videos. Sorely missed indeed.

[@tom0702x]

WOW! Best ever video of an E61 and its operation. Hats off to Seattle coffee Gear for such a clear and concise cutaway!

[@AngelGMiranda]

This is a great video! Thank you SCG staff and Mr. Crossland.

[@jamesakirk]

I watched several videos on the e61. This was far-and-away the best! Thanks!

[@espressorestomelbourne1735]

In the 1st stage before pump is on. There should only be a max of ~1bar as this is the pressure reached in the boiler. 9-12 bar is only reached when the pump is engaged.

[@pankuntakinte]

Correct! Good point.

[@morphiasas]

Hey Kat, remember whn Brandon ask bout why would there be 2 springs attached to the outlet valve? I like to dig in to mechanical stuffs especially figuring out how does coffee machine works... This video is truely gives me a clear explanation on how E61 works... Now back to the double spring setup on the outlet valve, I believe it works better using double spring instead of one since its high pressure there... I hope it's right...

[@mrazi9753]

Best video on that subject I've found, thank you.

[@fubartotale3389]

Early automobiles had no water pumps, they depended in thermo syphon to move water through the radiator and cool the engine. Very effective.

[@scd6969]

I would have never known how these things work without these awesome videos. Thank you!

[@thomasliu4545]

This is so inspiring! Thanks so much sir for such a detailed explanation!

[@JasonGriffin]

Hands down my favorite video you've ever posted. Extremely informative! (not knocking the Gail/Kat "crew reviews", those are great too)

[@SeattleCoffeeGear]

Hehehe, thanks! -Kaylie

[@snowman7234]

Old video but absolutely brilliant!! LOVE it!

[@PointlessMiracle]

To add to the question of replacing only the rubber gasket of the valves; yes it’s possible. I did it this week. Issue is that you have to remove the notch (and probably replace, as they wear). The bolt for the notch has about a 50% chance of breaking when you turn it loose because it’s either glued in or the temp & scale almost fuses the little m1 or m2 brass thread. A notch is 1.75€, a seal is 90c. A whole new valve is 9-10€.. so if you’re cheap like me, remove the notches, buy what breaks & seals / notch for the others. I broke my pre infusion valve and saved brew & exhaust.

[@henrikandreasson1177]

You can even flip the gaskets over and use the other side for a while if the rubber has not gone too stiff. That way you’ll at least be able to make coffee while waiting for the new gaskets to arrive. It’s what McGyver would do.

[@SeattleCoffeeGear]

I'm glad you enjoyed it! Bill's pretty awesome. - Kat

[@MrAlligam]

The Naval engineer in me understands how this design became the gold standard for all really good espresso machines. The coffee geek in me wishes he would have cut up another machine and donated that one to me.

[@morphiasas]

So after I figure it out it was the solenoid valves faulty... Which is the inner gasket gets harden and broke into pieces... That's how I realise pressure drop... Since the E61 is mechanical stuff, double spring would be ideal to keep the pin tight in place during 9bar+/- brewing pressures...

[@janfekkes1]

Thank you Kat and Bill! Very clarifying video! The only thing that is not clear to me is how the water gets from the thermosyphon system into the brewing circuit (under the mushroom onto the flow restictor jet).

[@SebastiaanSwinkels]

Thanks, that also explains the odd shape of the handle axle. It all makes sense now. Thanks =)

[@Squilliam-Fancyson]

Disagree the HX does not got water at 9bars unless pump is running. The pure pressure in the HX should only be about 0,5bar induced just by the heated water(around 104°-110° Celsius). Nevertheless prewetting does not rly work that great with HX machines unless it's plumbed to main water line.

[@Tomaluck]

Perfect material!

[@SeattleCoffeeGear]

Thanks!

[@Reefbrother]

That was an excellent video, very clear and informative Thanks!!

[@SeattleCoffeeGear]

Thank you - glad you liked it! -Kaylie

[@drewksidetour]

Very well explained

[@askay2k]

The correct answer to the question asked at 6:00 is the first chamber is called pre-infusion chamber, that spring gives away before 9 bar therefore slows down the pressure buildup on the puck.

[@nihilbaxter85]

Great Video!

[@SeattleCoffeeGear]

He actually dives deeper into this in the what is pre-infusion video; maybe check that out for further clarification on how pre-infusion works for machines on tank vs. plumb? - Kat

[@CarnivorousPlantsNL]

There is a push-button mounted behind the lever on the frontplate (1 inch next to the right of were the E61 brewheadis mounted), and when you push the lever upward to activate brewing, it pushed the button in and activtes the pump. ;-)

[@coffeemanray]

E61 HX requires flushing to cool the brew boiler tube aka heat exchanger until its stabilised to the correct temperature and also the exhaust valves are for depressurizing and diluting to prevent the lower exhaust from clogging

[@SeattleCoffeeGear]

There are copper tubes that have intake and exit at the back / internal to the machine and above the boiler - Kat

[@SeattleCoffeeGear]

Yeah, he's pretty rad :) - Kat

[@SeattleCoffeeGear]

I don't think so; the only way you could change this is too measure your line pressure from your house and possibly adjust the rotary pump if it's not meeting spec. Is your coffee brewing at the right pressure? If so, then I think you're fine; there's always going to be some passive pre-infusion happening from the pressure within the boiler that will start the process before full pressure hits it. How is your coffee tasting? To me, that's the most important thing to consider. - Kat

[@buttzbuttz11]

I'd love to see one of these videos for a lever machine.

[@SeattleCoffeeGear]

Another thing you could check is the setting for the rotary pump's pressure -- if you put it on with no coffee in it, where is it sitting at? Since I don't know what your line pressure is, I'm not sure what it is coming in at right now, but the rotary will mediate it during brew; if it's coming in really low to begin with, you might not see anything coming out of the brew head. Ultimately there's only so much I can TS over YT - have you called our techs to talk through it? - Kat

[@SeattleCoffeeGear]

You're welcome! Glad you enjoyed it - Kat

[@CarnivorousPlantsNL]

Fantastic video, keep these coming! Bye, Roger from the Netherlands.

[@SeattleCoffeeGear]

Thank you! Glad you dug it :) We have a few more with him that will be posting over the next week, all oriented toward technical explanations / walkthroughs. He's an awesome resource! :) - Kat

[@kaismimouni2679]

Seattle Coffee Gear

[@SeattleCoffeeGear]

Thanks! Glad you dug it - Kat

[@SeattleCoffeeGear]

I know that it has been used for testing / calibration re: temperature but not sure if that's the only use for it - Kat

[@SeattleCoffeeGear]

I can put it on the to-do list, but it's basically the same as a single or Hx machine if you check out those videos -- pull solution through the water spigot (steam side) and brew head (brew side), let it sit, then continue to flush through. We can shoot a demo of it, but if you need to do it soon, there's your how-to :) - Kat

[@SeattleCoffeeGear]

Great to hear!! - Kat

[@kmaglion]

Yes! ♥ Bill Crossland. Always makes me feel bad that I don't own a CC1

[@SeattleCoffeeGear]

Sounds plausible enough! :) - Kat

[@AC_Lerok]

The coffee tastes great, and the OPV will prevent the brew pressure from exceeding 10 bar, so I'm not sure that's a conclusive diagnosis of correct machine operation. If you could demonstrate the machine's plumbed-in pre-infusion function without a portafilter, I think that would resolve my concerns. Something tells me nothing is happening when Gail says "a little pre infusion" when pulling shots on rocket models running on tank.

[@SeattleCoffeeGear]

There's a very small amount that comes out just based on the pressure built up in the Hx, not dependent upon the line pressure. We don't have a way to plumb anything in right now so I can't demo that functionality for you, unfortunately. - Kat

[@ultraman8899]

Thank you for making this video, tons of good info. Is it possible to make a video on how to descale a dual boiler. Thanks,

[@SeattleCoffeeGear]

If we ever have one in here that we're willing to slice open, I'll definitely do so! - Kat

[@noir4hire]

Thanks! Great vid!!! I don't have a dual boiler, but would love to see a vid on proper de-scaling :)

[@cheeweitay3319]

Very insightful!! Thx for this video!!

[@SeattleCoffeeGear]

Got it on the list :) - Kat

[@SeattleCoffeeGear]

You're welcome! - Kat

[@AC_Lerok]

At 3:30, Bill explains that you would have the same amount as your line pressure flow into the coffee. This does not happen with my R58 plumbed in. This does not align with what Bill describes. I just want to know if my valves are not operating properly! :(

[@SebastiaanSwinkels]

Now the one question left is, how does the pump know it needs to engage and disengage?

[@einfussganger]

The top of that lever is actually cammed and presses against a contact switch on the housing when the lever is lifted.

[@SebastiaanSwinkels]

@@einfussganger Holy blast from the past.... I've learned a few things since I posted that question. Plus, I have an E61 myself now =)

[@redpunk]

Nothing in this video seems to suggest that that lever is a switch for a pump. It looks like it's just a crank that pushes on those spring valves. I'd also guess that there is steam in your brew boiler if you have a pressure gauge that registers several atm when the lever is "off".

[@stevewalsh5479]

There is usually a electrical momentary contact plunger switch behind the brew lever that is pushed on by the eccentric cam shape of the lever when it is raised to the brew position. The angle of this video doesn't show that switch.

[@mynineridesshotgun]

Awesome video!!!

[@thedonahoes]

That was great

[@TheKenan542]

Thank you very much for the explanation. I have a question. What if the green gasket in the upper chamber (good visible in the Video) was not there? Which effect would there be if i push the the coffee Switch to get water out of the shower Screen? Thanks in advance

[@peterschmidt3189]

I have degreased the brew group and replaced all the seals in the brew group, and water still comes out of the outlet during brewing. How can this be?

[@SeattleCoffeeGear]

Good thoughts! :) - Kat

[@sversimo]

My guess is that its there because you need to drill the hole, and then you seal the end with a screw.

[@BeyondWrittenWords]

this was very informative thank you

[@maha77]

this is so helpful. thank you!

[@SeattleCoffeeGear]

+maha77 Of course! Cheers!

[@tempestv8]

When operating the lever, do you lift up to the point where preinfusion starts and then wait a while (for the preinfusion to finish) before lifting further up to engage the pump? Or does one just lift the lever in one quick movement till the pump starts?

[@tektiteradio8178]

Hi guys I’ve just got myself a second hand ECM Cellini and the backwash system seems to be blocked as once I finish the poor nothing is coming out of the waste! Any ideas what this could be and how to fix it? Thanks x

[@mpa03061985]

My problem is no water coming in grouphead... How can i fix it? Please help me out.. Thank you

[@SaultiBalldeip]

Do you folks sell a E61 Group Repair Kit?

[@SeattleCoffeeGear]

What type of repair kit are you looking for?

[@SaultiBalldeip]

I have my Quickmill Alexia E61 all apart as of this morning and I need the upper and lower plane gasket that seals off the intake and exhaust valves. Mine are mangled and I am leaking steady water when pulling shots as a result. I am up in Victoria, BC. Cheers

[@AC_Lerok]

Awesome video! I'm concerned though. The low-pressure sequence Bill describes around 3:10 is non-existent on my plumbed-in R58. I have asked and asked and asked and have been unable to get a clear answer on this. When my lever is halfway, there is no preinfusion at all, and it has been that way since day 1. Should I continue to be concerned?

[@Kanointhejungle]

This video is 11 years old but I'm going to ask anyway. If everything is functioning normally except no water at the brew head and a bit at the exaust valve what is the most likely cause? My Giotto Evoluzione R has been in storage for 3 years and was shipped 8000 miles to the Philippines. It may have been shipped upside down. I can hear the pump activate when I activate the brew lever. The brew head gets hot. Thank you.

[@SeattleCoffeeGear]

Hello! This could frankly be a number of factors. If the boiler wasn't drained before transit it could be any number of things, but if you're seeing a bit of water come out of the release valve then I would guess it's got some heavy scaling or there is an issue with the pump (even if it turns on it could be running incorrectly). Unfortunately my best advice would be to look and see if there's any technicians in your area that work on espresso machines that you could have take a look at the internals.

[@Combat556]

So now I see why a chemical backflush will wash away any lube on the cam lever, but moreover, why the unit should be backflushed after every shot pulled.

[@1983Jacko]

Backflushing after every shot pulled is a bit excessive and I don't think it's necessary at all. Also, the chance of dirty water getting into your shot is very minimal since every time you turn the machine on and it heats up, you need to cool the grouphead by flushing for X amount of seconds before you pull your first shot. This will make sure the dirty water is removed and replaced with clean water for that first shot.

[@Combat556]

@@1983Jacko Thanks.

[@morphiasas]

I happen to come across a problem with my Linea3 brewing pressure drop during extraction...

[@johnbedford4511]

Hi. May I ask you a question please? The 36mm chrome nut on top of the group head on my Rocket is leaking water past the white seal. Oddly though, the leak stops when the machine gets hot, I presume this is because the seal has warmed up and the leak path is plugged. I've got a replacement seal but am a bit reluctant to undo the nut in fear of damaging something beneath it. Now I've seen your video I'm even more reluctant. So, is it safe enough to undo the nut, replace the seal and do it up again? Many thanks, John

[@SeattleCoffeeGear]

Hi John, We would definitely be careful with this nut. Ideally if you have a professional shop that can do it, that's best. I'd recommend reaching out to Rocket directly to see if they have any advice for how to handle the issue safely!

[@campbellmorrison8540]

Hi Great explaination. I do have a question that doesnt seem to be answered in the video. My E61 works perfectly putting water into the coffee and then when I move the handel back to flush the water it seems ok in that water comes out the exhaust. But what I find is the pressure meter is still showing brew pressure even in the exhaust position, this slowly leaks away or I have to move the handel back to the mid position which then seems to release the pressure back into the exchanger or somewhere, I can hear a fizzing noise and the pressure meter drops. If I dont release this pressure the coffee stays up in the head when I remove the potafiller, as soon as I release the pressure the coffee shot drops out with the portafiller exactly as I would expect. Any ideas what needs fixing, I have back flushed many times, the machine doesnt leak or drip, it works perfectly except for removing the coffee shot with the portafiller. Can you suggest anything?

[@cyber6850]

super la video

[@perrypix]

What is the screw on the front of the E61 used for. Cleaning with a pipe cleaner ?

[@RalphBambusVelo]

How can i modify the E61 to do pressure profiling ?

[@KozmoDyne]

I made it to 49 seconds and three "uh huh/mm-hmms".

[@snowzb]

back flushing explained! yay

[@stefanosalvia]

Hello, for some time I have had a problem with the excess pressure indicated by the pressure gauge at 12 bars. I replaced the pump, I did complete maintenance on the e61 group but the result is still the same. Do you have any ideas to help me? I would not want to touch the pressure setting of the pump, because I have been assured that it comes set at 9 bars from the factory (Fluide-O-Tech). Thanks for your help.

[@SeattleCoffeeGear]

This sounds like a pump issue, but you could try adjusting the solenoid valve to release some of the excess pressure, it's possible that it could help!

[@stefanosalvia]

@@SeattleCoffeeGear Many thanks for your response. Before receiving your response I nevertheless adjusted the pump pressure. Can you tell me how I could manipulate on the solenoid to adjust? Also, do you have any idea why I no longer have a few seconds of stopping around the 5 bars? Before I had an extraction profile of 5 bars for a few seconds and then slowly reached 9 bars. Maybe this can give you an indication? I thank you for your feedback. A fan

[@snjspring]

I have the Rocket R58. Looks like the ceramic mushroom has failed, froze, and I actually broke it in the removal process. Do you sell the e61 mushbroom brew part?

[@snjspring]

I'm referring to the piece with the large green gasket on it.

[@15aac]

Does the brew head of a regular commercial coffee machine work in the same way?

[@AdamHuntnz]

The main difference is they are solenoid operated. Instead of the lever, a solenoid mounted at the bottom of the head directs the water through a slightly different path up to the coffee. When it closes the exhaust exits through the valve. They are more prone to blocking so it's very important to use a filter on the machine that not only removes particulates but also calcium and the other minerals that can cause scale to build up. But IMHO overall the solenoid systems are simpler and more reliable for higher volume use.

[@holdtheonionsplease]

It seems like you could just put new gaskets over the valves instead of replacing the whole valve.

[@SeattleCoffeeGear]

From what I see in the video it seems like they don't sell them individually. - Steven

[@sandertje81]

+holdtheonionsplease The normal maintenance sets often include only the gaskets. You're right, replacing the whole valve (times 3) is absolutely not necessary.

[@bryangrimshaw5607]

everything is available separately. the seals are held in by a washer and you simply unscrew the square or triangular spiggot. sometimes of course the threads get jammed they are only M3, but it is easy enough to replace if they break. sometimes i think people are not servicemen but parts replacers. the customer will pay so just replace it all. not a good look.

[@einfussganger]

The three valves will (with seals) will set you back about $50. The top of the pins that engage with the cam do wear over time, so I had no qualms about replacing the valves - especially since I could not find the exact seals and my machine was down. After 8 years of daily use, it took all of 30 minutes to tear down the group head and replace the seals and valves.

[@SeattleCoffeeGear]

Hahaha; well, we removed the E61 from a machine that was already being cannibalized for parts so ... it wouldn't have worked for you anyway :( - Kat

[@kompass3670]

Anyone have any idea how to fix if too much water comes out? It's now making regular coffee by the amount of water coming out. Any help on which screw to tighten if that is happening? Thank you in advance.

[@paviaaPS3]

Dez Nay use finer coffee and press it harder. In that way water will have slower flow rate

[@henrikandreasson1177]

Make sure your brew pressure is not too high, that will force too much water through the puck even with a finer grind. Adjust at the pump if rotary, or OPV if vibration pump.

[@zm23f]

Those epdm black seals are totally replaceable!

[@mwcalder95]

Purge your group heads everyone!

[@SeattleCoffeeGear]

:)

[@DunateoRom8v37]

Let's go Brandon

[@asexykane7811]

Stop saying OK all the time, please!!!

[@SeattleCoffeeGear]

Yeah, he's pretty rad :D - Kat

[@SeattleCoffeeGear]

:D