Espresso Machine Boilers: See Inside 4 Types

Learn how 4 types of espresso machine boiler work. Using cutaway models, go inside an E61group, dual boiler, heat-exchange boiler, single boiler and thermoblock boiler. E61 thermosiphon operation explained plus PID vs. pressurestat operation/benefits, scale deposits and flow control of E61 brew group.
Related videos:
How To: 5 Flow Control Profiles for E61 Group Espresso Machines: • How To: 5 Flow Profile...
How to Descale a Heat-Exchange Boiler: • How To Descale Espress...
What's in Espresso Machine Descaling Products and How to Make Your Own Descaler: • What's in Espresso Mac...
WHOLE LATTE LOVE
Get expert advice on products to best fit your needs. Call the coffee experts at Whole Latte Love:
585-924-7170
Talk to our experts via chat or email: www.wholelattelove.com/contac...
Whole Latte Love on Social Media
---------------------------------------------------------
► Follow Whole Latte Love on Instagram: / wholelattelove
► Follow Whole Latte Love on Twitter: / wholelattelove
► Like Whole Latte Love on Facebook: / wholelatteloveonline

[@a395205700]

so informative and visual! Been wanting a video like this on boilers for a while. Thank you so much for your work!

[@Wholelattelovepage]

Hi UkeJJ, You are welcome and thank you for the comment! Marc

[@kennyhills8002]

I've watched this video several times now. And I'm finally getting a heat exchanger machine!.

[@robertrybczynski4107]

One of my favorite videos from you. I have a much better understanding for when I have to replace my current espresso machine. Thanks so much!

[@Wholelattelovepage]

Hi Robert, You are welcome and thank you for taking a moment to leave a comment - it's appreciated! Marc

[@sofronio.]

Thank you sir, this is the most interesting in-depth boilers video I have ever watched.

[@Wholelattelovepage]

Hi S, You are welcome and thanks for the comment! Marc

[@marcochiasson2298]

Just love going to “coffee school” early morning sipping away on my espresso. Well done. 👌 I was surprised to see how small is a single boiler compared to HX boiler.

[@Wholelattelovepage]

Hi Marco, Thanks for the kind comment! Yes, there is quite a difference. Should mention the Classic boiler is one of the smaller ones. Marc

[@wastelandrebel]

Watching Mark talk in this video is my meditation. Thanks Mark!

[@Wholelattelovepage]

Hi wastelandrebel, You are welcome and thanks for the comment! Marc

[@rlmartin1988]

That was freaking awesome! Thanks so much for putting this together.

[@Wholelattelovepage]

Glad you enjoyed it! Marc

[@TheSageSpeaksB4U]

Thanks Mark, this is the second time I watched this. First time I was just starting to think about a new machine, but this time I actually understood which type I wanted in my machine. Since I don't do a lot of entertaining anymore, I think the Heat Exchanger with PID is right up my alley. I'm not sure when I can order, but hopefully soon. Thanks again!

[@Wholelattelovepage]

Hi Jeff, you're welcome! Marc

[@omrirechani1104]

Absolutely love your informational stuff. keep'em coming!

[@Wholelattelovepage]

Hi Omri, Will do and thanks for the comment! Marc

[@AS-wi6hr]

Amazing video!!!! (very very informative)

[@seugeniogonzaleze9296]

Fantastic video! Thank you very much for sharing your knowledge

[@Wholelattelovepage]

Hi SGE, You are welcome and thank you for the kind comment! Marc

[@user-cj1br1hx9q]

Great video Marc and crew 👍 no other channel even comes close 👏

[@Wholelattelovepage]

Hi Conor, Your comment is appreciated - we aim to be the best! Marc

[@dhenschel4]

Nice work, thanks for showing all this information in the internals, something I can only learn by tearing a machine apart.

[@Wholelattelovepage]

Glad you enjoyed it

[@lillylola9822]

Thank you for the awesome video. Helps me a lot to make my decision about my next Espressomachine. Greetings from Germany!!!

[@Wholelattelovepage]

Hi Lilly, You are welcome and thank you for the comment. If in Germany support local and go with a Profitec or ECM. They have manufacturing facilities in Germany and Italy but Michael Hauck the CEO is German. Marc

one of the best video so far. thank you .

[@Wholelattelovepage]

Hi DA, Thanks for the comment! Marc

[@amelialee9996]

Great video. It’s important that water doesn’t get too hot, nor lose too much heat for great consistent coffee

[@Wholelattelovepage]

Hi AL, Yes, thanks for the comment! Marc

[@kevinjamiesonbelou]

I could watch this guy for hours.

[@marekwidomski5958]

Great video ! Thank you so much for your work!

[@Wholelattelovepage]

Hi Marek, And thank you for the comment! Marc

[@er.mannov5735]

Just learned a ton! Great visuals!

[@Wholelattelovepage]

Hi e, Thanks for the comment and happy to hear you learned a ton! Marc

[@shenghofu]

this video is just so great, thanks a lot for so many information.

[@Wholelattelovepage]

Hi sFu, You're welcome! Marc

[@jashahh4274]

Marc bringing the heat as usual. Great vid!

[@Wholelattelovepage]

Hi Jash, Thanks for the comment! Marc

[@akquicksilver]

Excellent info! Thank you sir!

[@Wholelattelovepage]

Hi JB, You are welcome and thank you for the comment! Marc

[@ryanyepp50]

I love your channel, please do more videos on explaining how different espresso machine works.

[@Wholelattelovepage]

Will do!

[@vladkalina69]

Excellent video!!

[@canadian_coffe_guy4690]

Great video Marc! The ECM synchronika is still my dream machine. One day!

[@Wholelattelovepage]

Hi Andy, Thanks for the kind comment! ECM Synchronika is my favorite DB! Marc

[@GadgetsGearCoffee]

Top content! Thank you for this

[@Wholelattelovepage]

Hi Jess, You are welcome and thanks for taking a moment to leave a comment - it's appreciated! Marc

[@sailorguy9288]

Best video over a simple coffee brewer

[@Wholelattelovepage]

Wow, thanks! Marc

[@rickseneris]

Very educational seminar style video.

[@Wholelattelovepage]

Thank you!

[@MonkeyBlueAss]

Thanks for cutting boilers

[@Wholelattelovepage]

Most welcome 😊

[@babackd.6485]

Marc, you are amazing at explaining and teaching. Respect from Iran

[@Wholelattelovepage]

Hey BD, Thanks for the kind comment! Marc

[@babackd.6485]

@@Wholelattelovepage 🥳🤞🏻

[@renegade3935]

fantastic 👍👌😊 helped me a lot to understand how my machine works

[@Wholelattelovepage]

Great to hear!

[@gurthang53]

Loved your video, you are a true Professional

[@Wholelattelovepage]

Thank you so much 😊

[@itsjaynguyen]

awesome vid THANK YOU!

[@Wholelattelovepage]

Hi Jay, YOU'RE WELCOME! Marc

[@rayadelic4327]

Thank you great explanation

[@Wholelattelovepage]

Hi Ray, You are welcome and thank you for the comment! Marc

[@YTesting]

Amazing, thanks!!

[@Wholelattelovepage]

Our pleasure!

[@drewyush5064]

best video by far. Well done

[@Wholelattelovepage]

Hi Drew, Thanks a million for your comment! Marc

[@chang69123]

Super cool video! Thank you.

[@Wholelattelovepage]

You’re welcome and thanks for the comment! Marc

[@zakac17]

Thanks for the great video!

[@Wholelattelovepage]

Hi z, You are welcome! Marc

[@glenmoralee3]

Thanks for that. Very good.

[@Wholelattelovepage]

Hey Glen, you’re welcome! Marc

[@toohardanouar]

this was a great informational video !

[@Wholelattelovepage]

Hi ABC, Glad you enjoyed and thanks for your comment! Marc

[@agustinrosso4554]

A really good video abouth the boilers!! I'm on a personal proyect to make an espresso machine, an I just was looking información abouth the boilers, thanks a lot for making this kind of videos!!!

[@Wholelattelovepage]

Hi AR, My pleasure! good luck with your project. Marc

[@sahirdiesh6386]

Great presentation

[@Wholelattelovepage]

Glad you liked it! Marc

[@MrArdytube]

This is very informative. I was wondering how thermo blocks work... and also did not know the Gaggia had the boiler sitting on top of the brew head... which is a good idea. Thanks Marc

[@Wholelattelovepage]

Hey Ardy, Thanks for the comment. Placing the boiler there really helps heat the group. Many smaller machines have the same setup. Marc

[@MrArdytube]

@@Wholelattelovepage Marc, I have a question about these less expensive machines temperature stability. I have a vintage Silvia that I have modded with a pid. One thing I see about this set up is significant temperature instability. I have been able to compensate for this because I can see the temperature. But, for example, what I notice is that ... even if I have ideal boiler temp when I start the brew, the boiler temp drops rapidly ... which I think is because of cold water entering the boiler. And, my guess is that this problem would be worse in a machine with a smaller boiler machines .... like the gaggia Do you have any thoughts on this issue?

[@mikejason3822]

Great informative video!

[@Wholelattelovepage]

Hi Mike, Thanks for the comment. It's appreciated a whole latte! Marc

[@guymross]

I love these videos. Thank you!

[@Wholelattelovepage]

Hi Guy, Thanks a whole latte for the comment! Marc

[@guymross]

@@Wholelattelovepage thank you for my newly descaled Pasquinii!

[@davidleigh3636]

Really decent and informative video💪🏻

[@Wholelattelovepage]

Hi DL, Thanks for the comment!

[@technicalissues9514]

Thanks sir nice explanation

[@Wholelattelovepage]

Most welcome

[@pankuntakinte]

Nice presentation 👌

[@Wholelattelovepage]

Hey RK, Thanks a lot! Marc

[@HaveAGoodHeart]

This is a very very good video. Tks

[@Wholelattelovepage]

You are welcome!

[@hasufinheltain1390]

It's great to see this - especially the heat exchanger; most explanation of that are very confusing.

[@Wholelattelovepage]

Glad you enjoyed it

[@XerxesGustav]

Maybe its worth mentioning that depending on the composition of your water you will get severe pitting of an aluminum boiler like the gaggia one. I have had 2 gaggias, and both of them needed the boiler changed within 6 years of manufacture. The sealing surface between the grouphead and the aluminum top part will get pitted to the point that it wont seal anymore and it will leak. By the time i noticed on the first one it had been leaking long enough that the screws were so rusted in place that the grouphead needed changing as well, if you do that repair at a repair shop its will cost you more than the value of the unit. So my advice is if you have a chlorinated or acidic water (de-mineralized water is usually acidic) dont go for a gaggia or any cast aluminum boiler, they are not designed to last.

[@Wholelattelovepage]

Hi XG, Thanks for sharing your experience. I'm fairly vocal on water quality. Any chance you were using pure distilled or RO water in your machine? Not sure but you mentioned demineralized water so taking a guess. Water is a good solvent and zero TDS pure RO or distilled water is even better. So good it can cause corrosion of metals - and not just aluminum. That mineral free water pulls ions from the metal. I get a lot of comments from people thinking they are doing the right thing using mineral free water in machines to avoid lime scale deposits but the truth is they are not. Beyond causing corrosion over time those extra pure waters over-extract coffee causing bitter flavors. Marc

[@ropehitch]

@@Wholelattelovepage OK you just blew my mind again. Third time this evening. I love that you give such detailed (and informed) answers to all of these comments. Great engagement & community creation. And coffee, ultimately :)

[@babackd.6485]

@@Wholelattelovepage so, what kind of water is more suitable for a espresso machine?

[@rxonmymind8362]

​@@babackd.6485 Unicorn water.

[@ropehitch]

Awesome video. You are obviously not only very knowledgeable but you also have the ability to communicate these concepts that you understand so well. The combination is rare. Kudos and thanks. I found this fascinating and extremely valuable. Since I never make milk drinks I know that heat-exchange and double-boiler features are not necessarily important to me but PID and pressure control are. So, a modified Gaggia classic (with PID and pressure fader with gauge) would be OK for me. I think. Maybe I'm missing some subtleties. I wonder if there is a high-end machine that has those same features (PID & pressure control) without the unnecessary (at least for me) expense of a double boiler or heat exchange? Great job, Marc.

[@Wholelattelovepage]

Hey ropeh, Thanks for the kind comment. Sounds like the ECM Classika PID w/flow control is exactly what you are looking for: www.wholelattelove.com/products/ecm-classika-pid-espresso-machine-with-flow-control Checks all your boxes: PID, flow control, E61 group, single boiler focused on those who don't do milk drinks very often. ECM build & finish quality are best in the business. While modding a Gaggia Classic is a possibility, the Classika is purpose built and has far better thermal stability. Marc

[@ende421]

Also consider the ECM Puristika if you never steam milk.

[@ropehitch]

@@ende421Thanks for the tip on the Puristika. That is the machine for me.

[@GraemeRobinson]

copper has anti-bacterial qualities that make it preferable to steel or other materials. If water sits in the machine for long periods this can be an issue. Enjoyed the cutaways very much - thanks for the effort!

[@Wholelattelovepage]

Hi GR, You are welcome and thanks for the comment. Yes it does. Marc

[@mjmjersey]

Marc this is an excellent video

[@Wholelattelovepage]

Hey michael, Thanks for the comment! Marc

[@mjmjersey]

Hey Marc I went out for a little while today and I accidentally left my machine on for about 4 1/2 to 5 hrs today do you think I did any damage to my profitec Pro 700

[@enzonl]

Whole Latte Love the best video ... it is so good to learn about these machines...btw Is the Bezzera BZ13 DE PID discontinued?

[@Wholelattelovepage]

Hi enzonl, Thanks for the comment! BZ13 DE out of stock at the moment but more on the way. It's been a very popular machine. Marc

[@nattyphysicist]

Loved it! So in that last one, how does the pump fit in to the equation?

[@Wholelattelovepage]

Hi np, Thanks for the comment and question. Pump automatically fills the service boiler based on reading from water level probe. Brew boiler is filled by raising the group lever. Marc

[@l.l.coolray]

On the dual boiler, will using hot water damage the heating element as it will become exposed, or dose it fill up just as fast as it empties. Fantastic vid couldn't stop watching.😎👏👏

[@Wholelattelovepage]

Hi LLCR, Thanks for the awesome comment and question. On the DB machine hot water comes from the service boiler. The heating element in that boiler sits well below the minimum water line. As soon as the water level probe senses the drop in water level the pump kicks on to maintain the water level above the heating element. Marc

[@tonyb83]

Useful info. thanks. It would have been better if you explained how the flow to the group head when making coffee took place.

[@Wholelattelovepage]

Hi Tony, Thanks for the comment.

[@s96822]

the Decent espresso machine seems to also use a thermoblock like design but it is the tesla of espresso machines and not cheap either. at recent milano host show there was a multigroup swiss commercial machine usiing thermoblock

[@marcojimenez2725]

Wooooow great video!!!! 🖤⛓🥀☕

[@Wholelattelovepage]

Hi Marco, Thanks for the comment! Marc

[@mohamedfaroukbalouli7809]

This is a channel that you would never regrete subscribing to

[@Wholelattelovepage]

Hi SC, Well thanks for a not sketchy comment! Marc

[@mohamedfaroukbalouli7809]

@@Wholelattelovepage Thanks man

[@nicouh]

That is really interesting and well presented, thank you! Out of curiosity a engineering question, how are the thermoblocks made? How do you get the spiral hole for the water flow into a block of solid aluminium?

[@Wholelattelovepage]

Hi n, You are welcome and thank your for the comment and question. Inside the aluminum block the spiral is a stainless steel pipe. My assumption is that pipe and the heating element which spirals through the block as well is held in a mold and the metal is poured. Marc

[@MonkeyBlueAss]

Molted aluminum is poured around two spirals colis one for water other for heating element

[@pizzablender]

I've seen a gaggia commercial machine that had the group head electrically heated. Heats up very fast and doing that with a PID would make it very accurate as well. Pity that system isn't more widely used.

[@Wholelattelovepage]

Hi p, Thanks for the comment. There are some machines using this approach. The Bezzera Matrix and Duo machine have a triple PID setup with a PID controlling each boiler and the 3rd controlling a heating element in the group. In that setup the group's PID temperature is preset and not user adjustable to best of my knowledge. Dalla Corte machines use a more controllable setup with PID temp control of a boiler over group design. DC machines are fully up to temp in

[@jimmyv8307]

Thanks for the informative video, does anyone have any experience with the Ascaso heater blocks with stainless steel coils ?

[@Wholelattelovepage]

Hi jv, Thanks for the question. I do not but they are available from parts suppliers if yours is bad. Marc

[@spookyactionatadistance2422]

all this engineering to make good coffee. Gotta love humans for this... when they like something they really go to great extents to make the perfect "what they like".

[@Wholelattelovepage]

Hey QL, Thanks for the comment!

[@David_Best]

Great video. Not clear how a PID controlled heat exchanger machine works however. Your video seems to overlook the fact that PID's are not just on dual boiler machines, but are also found on heat exchanger machines.

[@Wholelattelovepage]

Hi David, Yes, many modern HX boiler machines use PID for better temperature control. Much more precise and accurate than those controlled by pressurestats. PID in an HX boiler holds the main boiler section which produces steam at a precise temperature. Brew water runs in a closed looped through the heat-exchange section within the main boiler absorbing heat. Convection causes the heated water to flow out to the group where it gives off heat and returns cooler to the heat exchanger. This flow out to the group and back is continuous. The result is water in the loop runs well below the temperature of water in the steam producing section of the boiler. By engineering the flow rate by adjusting the size of a flow restrictor in the loop one gets predictable brew water temps based on an offset from the main boiler temperature. Marc

[@jph364]

How does the pump put pressure on the group. I note a connection between the steam and brew boiler on my Alex duetto with a hose ending uo in the drip tray. is the pressure on the brew boiler regulated by pressure in the steam boiler. Love videos like this, please go geekier!

[@Wholelattelovepage]

Hi jp, Thanks for the comment and question. I will get geekier - I love this stuff too! It's a fairly straight connection between the pump and brew boiler. The group gets pressure from the pump and there's no involvement with pressure from the steam boiler. Even if there was steam boilers generally run at under 2 bar of pressure so no way to get 9 bar out of the steam boiler - it would have to run at about 180C/356F to generate that pressure! There is a device called an OPV (over pressure valve) which regulates pressure from the pump in many machines. On rotary pump machines there's a bypass on the pump which regulates pressure. Marc

[@fromtheflightdeck252]

Good video

[@Wholelattelovepage]

Hey Flight Deck, Thanks for your comment! Marc

[@fromtheflightdeck252]

Thanks Marc. Keep up the good work. You are good at explaining everything and honest and natural. You sold me on the Gaggia Classic from your videos. Love how you show everything including the little tricks and hacks to get the best from the machines.

[@hongli914]

Thanks so much. On the dual boiler why doesnt the small boiler have a vacuum valve but the big one does?

[@Wholelattelovepage]

Hi Hong, Thanks for the question. The steam boiler in a dual boiler and the steam creating section of heat exchange boilers need a vent to atmospheric pressure during initial filling with water so air pressure does not build up inside.

[@g12196]

Awesome video! Need recommendation. I have an Alex Duetto 2, not working so well. First issue was at powerup the pump would run and run till a fill alarm would stop the pump. Reservoir is filled no water being drawn. Started happening intermittently, descaled machine hoping to fix this issue. It did not - eventually happened on every power up. I Replaced the fill valve/solenoid - problem did not go away. Found sediment in the valve under the solenoid, fill problem was solved. Machine worked for a week, then more problems started. Seems every time I have my steam boiler on the brew and steam boiler temps fluctuate by +/- 10 deg. While drawing a shot. Would take a few minutes to recover back to normal temps. I used it this way for about a weak, steaming my milk first then shutting off the steam boiler before making my shots. Today: If I leave both boilers on, now and try to make my espresso first it’s gotten worse the steam boiler blows the safety valve every time I draw from the group. I’ve removed several parts in the piping and descaled them separately, expansion valve, one-way valve, group head components. Problem persists. I thought perhaps the pump has a large chunk from scale in the impeller causing back pressure and blowing the safety valve. Or the fill probe cannot conduct to ground from too much scale inside the boiler, so boiler overfills. Would you recommend removing the pump to inspect it and clean it? How about removing the boiler to descale? Or perhaps not removing anything and trying to descale once again. Any advice would be greatly appreciated. Thank you

[@Wholelattelovepage]

Hi Paul, A lot going on there! Sounds like you've seen evidence and/or believe the machine has significant scale deposits. I don't know if this is the case with your machine, but descaling a machine with a lot of scale already in place can cause a lot of problems. Scale dislodges during descaling and ends up plugging up other parts of the machine. Based on what you've said if this machine came into our shop it would be a tear down with boilers and other components removed for descaling. In fact, that's the only way our techs descale dual boiler machines. I would not recommend descaling without removing components. Sounds like you have some skills and a total tear down and check of all hydraulic components and sensors like fill and temperature probes is called for. Marc

[@g12196]

@@Wholelattelovepage Thanks for the quick reply, you’ve confirmed what I believed had to be done, but was hoping I could get around removing the boilers to descale. My plan is to descale the remaining components, once I’m satisfied the plumbing is clean I can troubleshoot any remaining issues at least knowing that it’s not related to scale. Thanks again.

[@karl6508]

I still have my Gaggia Factory I got from Whole Latte Love 20 years ago. It works and looks brand new still while using it twice a day!

[@Wholelattelovepage]

Hi Karl, That's awesome a real classic! Marc

[@ElieCreative]

I'm relatively new to espresso machines but learning quickly thanks to content creators like yourself. I own a Breville touch which has a thermocoil system. Can you explain why you consider this entry level? I understand it is more susceptible to scale buildup/blockage and might not last for years, however, it seems to me that for home use (1-4 cups of coffee a day on average) this is the preferred machine since the water heats almost instantaneously and you can jump from brewing to steaming within a few seconds. The pressure seems adequate enough for brewing (perhaps could be better for milk texturing). Is the temperature fluctuations in a thermocoil machine an issue? Am I missing anything? Why would I want any other system for home use?

[@Wholelattelovepage]

Hi EC, Thanks for the question and happy to help! With thermoblocks it comes down to temperature control. It's just not as precise as machines with true boilers and group heads with large thermal mass. A hot group and pre-heated portafilter makes a difference. That said if your happy with the coffees you're making on the Breville then it works for you. Maintain the machine well by using good water quality and/or descaling on schedule and it should continue to provide service for some time. The big difference comes down the road in reliability. Machines with true boilers are very serviceable and can run for decades. The service life of products like the Breville are shorter. Depending on age, when they have a problem repairs are difficult to impossible to DIY and professional service generally cost more than the remaining value. On steaming, go to a true machine with an HX boiler and you'll get better steam pressure and you can brew and steam at the same time. Steam is always available so no waiting. Hope that helps, Marc

[@anastasiya256]

I had the same question, since I am quite new to espresso machines, so thanks for asking! I am also wondering why having the two separate boilers is considered better than the heat-exchange dual boiler setup. Heat exchange seems more economical from the point of not wasting heat… (or is that not the case?) Is the benefit of having two full boilers that it allows for a larger reservoir of hot water and of steam? So, more suitable to people who need to make several drinks in a row? Is the temp control also more fine-grained somehow?

[@MonkeyBlueAss]

No descaling access inside the boiler for maintenance and inspection or modding + mostly not dual boiler

[@ende421]

There are a lot of entry level machine using thermoblocks. Your Breville is somewhat above entry level. But there are really good mid and high range machines using thermoblocks as well: Ascaso PID Duo and Baby T Plus and of course the Decent machines. So thermal management can be excellent with thermoblocks. I guess service can be an issue on these? Also the four types Mark shows here are only the most common. There are saturated group heads with service boilers in front and different types of lever machines for example.

[@vald447]

Would you guys be able to make an energy usage comparison between all those boiler models?

[@Wholelattelovepage]

Hey V, Thanks for the request! I did do this video on energy consumption a few years ago. Probably not exactly what your looking for but maybe some: kzbin.info/www/bejne/lZTKloGeqKd3l9k Marc

[@bigglyguy8429]

Sweet vid! I've opted for the dual-boiler with PID Silvia Pro. Now I'm wondering how you go about descaling it, as I've heard it's difficult to descale a dual boiler? I've ordered it but it has not arrived yet :)

[@Wholelattelovepage]

Hi b, The Silvia Pro is a real value in dual boiler PID machines - congrats on your purchase! In the box with your machine will be a BWT Bestsave M drop-in filter like this: www.wholelattelove.com/products/bwt-bestsave-m-anti-scale-filter If you use the filter as directed no limescale should form in the machine so descaling will not be needed. Depending on your source water hardness the filter is good for treating up to 100 liters of water. It just drops in the reservoir and does it's thing. Be sure and refill reservoir 10 hours prior to use so the filter has time to do it's thing. A nice feature on the Silvia Pro is the ability to automatically drain the boilers through extended functions on the PID display. This is handy for long term machine storage and could be used if someday you find the need to descale. Be aware you will not find descaling instructions in the Silvia Pro's manual. Rancilio likely prefers you use the BWT filters to prevent scale in the first place. Be aware descaling neglected dual boiler machines can be risky! The have rather intricate internal plumbing. Scale chunks can come off during descaling of neglected machines and plug up internals. Marc

[@lama8198]

Thank you Mark. Always wondered just how the "outside" element look like on the Gaggia. This then also mean that the 140ml Gaggia boiler is a true 140ml, and that boilers like the Rancilio, although bigger, might lose some volume due to the heating element. Or do they measure actual volume?

[@Wholelattelovepage]

Hi La Ma, You are welcome and thanks for the question. I believe most manufacturers measure the entire internal volume and probably do not subtract displacement of heating element.

[@MonkeyBlueAss]

@@Wholelattelovepage and do not subtract air volume from this boiler

[@cliveclapham6451]

Who doesn't love 💕 cut-a-ways ❤️🎯

[@Wholelattelovepage]

Hey Clive. I sure do!!! Marc

[@jomivo]

What a great explanation! My Gaggia CC is now I would guess at least 20 years old and still running more than fine, but as you've showed the inside of that boiler I was wondering if I should take mine apart to give it a good scrub. Any opinions on that? As I've bought the machine used 5 years ago I don't know if the boiler got replaced at any time.

[@Wholelattelovepage]

Hi Jonas, If you've got the skills it certainly would not hurt to have a look under the hood of a 20 year old machine. That longevity with basic maintenance is why I always recommend people avoid the cheap entry-level appliances and go with true machines. Marc

[@jomivo]

@@michael3724 if you can hit both of those ends just go 50/50. If that's no option go for the cleaner water. It will go easier with the machine

[@bsdickinson]

Hi Marc - love your informative and lively videos - thanks for making them. Just ordered an ECM Casa V and Eureka Mignon Specialita grinder from Whole Latte Love. Do you have a video showing the Casa V boiler in cutaway? Does it look very similar to the Gaggia single boiler shown in this video? Wondering if the water that goes into the steam and/or the brewing on the Casa V is heated up in the (brass?) boiler or stays in copper tubing that runs through the boiler wall and is is heated by the boiler. Interested in your response. Thanks!!

[@Wholelattelovepage]

Hi Brian, You are welcome and thanks for the kind comment, question and your patronage! Casa V + Specialita is a very nice combo. I do not have a video with a cutaway of the boiler. The boiler does not operate in the same manner as the Gaggia boiler. The Casa V uses and ECO brass boiler. The "ECO" references food safe brass which passes EU regulations (stricter than most US standards). The boiler is heated by an internal heating element similar (but smaller) to those seen in the HX and DB boilers in this video. Hope that answers your question. Marc

[@bsdickinson]

@@Wholelattelovepage Thanks Marc. Can you compare/contrast the common and different aspects? Only takeaway from your response is "its different" and has a "food safe brass build". Not sure how it is same/different in construction or function. Thanks!!

[@HaramKim_CoffeeandSugar]

Hello Mark, This is very helpful. I sort of knew how those boilers work in theory, but didn't know how they actually look from inside. Thanks, One question if you don't mind. 😊 Why is it mostly recommended to descale dual boiler machines by professionals? What possible risks do they have if descaling is done at home?

[@Wholelattelovepage]

Hi Thanks for the comment and question. A couple of reasons manufacturers recommend only pros descale dual boiler machines. 1. Avoiding unhappy customers. Manufacturers know machines are often neglected. A customer may use water with high mineral levels causing scale. When customer tries to descale a machine with significant scale build up the process can release large scale particles and cause problems in machines. Dual boiler machines have more complex plumbing with more areas prone to getting plugged up. 2. Depending on dual boiler machine make it can be difficult to drain boilers to remove descaling solution. It's not impossible and repeated dilution with fresh water can work. Old trick to know if rinsed enough is to put some baking soda in the water coming out of the machine. If descaling acid (usually citric acid) is still present the baking soda will fizz. Our service center rebuilds and refurbs many dual boiler machines. For descaling those they always remove the boilers from the machine. We recommend owners of dual boiler machines use advanced filtration of water to reduce total hardness with ion-exchange which swaps out magnesium for calcium. Proper use of that type of filtration in most cases totally eliminates the need to ever descale. Ion-exchange filtration tech is available in BWT products in the form of drop-in reservoir pad filters, a pitcher and cartridge for plumbed in machines www.wholelattelove.com/collections/bwt Marc

[@HaramKim_CoffeeandSugar]

@@Wholelattelovepage Thank you so much for the answer with very detail information. i love your baking soda trick! I'd like to try it next time. :)

[@ropehitch]

@@Wholelattelovepage That is fascinating and I'm so glad there is someone with this level of technical knowledge sharing this info. Next time someone says "oh, I fix espresso machines for a living" I'll understand that they are part chemical engineer, part materials engineer, part electrical engineer, etc. I had no idea it was so technical.

[@Chevyxs]

Can you elaborate more on the brew boiler not needing a fill probe sensor? Amazing video btw. @11:59

[@Wholelattelovepage]

Hi BL, Thanks for the comment and excellent question. The brew boiler fills completely on machine startup. When pulling a shot, the pump pushes water into the boiler and the only exit is through the group head so the boiler is always completely full. On the other hand, the service (steam) boiler must have empty headspace to hold steam. A fill probe in that boiler makes sure the boiler only partially fills. Hope that helps! Marc

[@Chevyxs]

​​@@WholelattelovepageThe Marc? Is such an honor, you've been with me since day one in my espresso endeavors. Needless to say I am fan of your work. Keep up the good work! Thanks for the explanation. I am just having a hard time wrapping my head around the boiler not having a way to check for water coverage of its heating element.

[@mpoisot]

Those cutaways are amazing! Why do heat exchanger machines measure pressure instead of temperature?

[@Wholelattelovepage]

Hi Marcel, Thanks for the comment and question. Because science is cool one can accurately determine temperature using boiler pressure. Although PID control is becoming more common in HX boiler machines for a long time pressurestats were used to regulate pressure/temperature. As the name suggests pressurestats measure pressure so pressure gauges are used on those machines. PID machines have a temperature probe in the boiler instead of a pressurestat. PID machines are more accurate using an algorithm to control heating in boiler and avoid under or overshooting desired temperatures. Marc

[@mpoisot]

@@Wholelattelovepage I feel like I’m still missing something. If measuring pressure is faster or more sensitive than measuring temperature for an HX machine, then why not feed pressure measurement to a PIDed HX as well? Why go back to measuring temperature? It seems odd that both low and high end setups use temperature, while mid range uses pressure. Is the PID thermometer way better and more expensive? Or is a digital barometer (for input to the PID) much more expensive than a digital thermometer?

[@metaphysician9]

I have the first type that you show. Its a betty Crocker 1425 or 6. My question is: Is the water being bathed in aluminum? Is the housing aluminum? Is plastic coming in touch with the water? Please explain, thank you Marc!

[@Wholelattelovepage]

Hi m, Unfortunately I'm not familiar with Betty Crocker machines :( Marc

[@Thrilos30]

Amazing content as usual! I was curious, I have a Profitec 500 PID and use a BWT penguin pitcher, should I still descale my machine?

[@Wholelattelovepage]

Hi CP, Thanks for the kind comment. Pro 500 among my favorite PID HX boiler machines! I use a BWT Penquin pitcher for all reservoir filling in the studio. According to BWT water filtered with the Penquin pitcher should not cause scale accumulations in espresso machines. Marc

[@Thrilos30]

@@Wholelattelovepage awesome! Thanks for your response!

[@dnice4441]

Are the new thermablocks in the ascasos much improved? Or do you recommend another type, HX vs boiler? Water is also dard in Calgary.

[@Wholelattelovepage]

Hi Dennis, Thanks for the question. I believe the machine uses a stainless steel lined aluminum thermoblock boiler. But, it's not a machine I have contact with so I do not know if boiler improvements have been made. I'd guess probably not. Thermoblocks with their very narrow passages for heating water are more susceptible to clogging due to scale. A boiler with a larger volume like an HX is more immune to scaling issues but use hard water in any boiler type and you can have scale problems. Troubles can be avoided by filtering water to reduce (but not eliminate) mineral content and by descaling the machine on schedule. Marc

[@gundelfish]

Thx a lot for the good explanations with the great displays! Wrt thermoblocks, did you check the Ascasa machines? Wouldn't say these are entry level machines, especially the price tag. Looks like a lot of engineering went in those.

[@Wholelattelovepage]

Hi O, Thanks for the comment. I have not. Marc

[@gundelfish]

@@Wholelattelovepage Sorry, little typo: meant Ascaso not Ascasa

[@benaiscam]

nice ex explaining

[@Wholelattelovepage]

Keep watching

[@donvincent1291]

Problem with thermal siphon stall. I did some temperature checks. The boiler stays hot at all times. The grouphead cools after each shot and will not heat up unless I do a long flush. I did 30 second flushes then it would heat up. I used three thermocouples to check the temperature of the boiler, the grouphead inlet pipe and the grouphead outlet pipe. See the attached PDF for the temperature/time log. It seems to me that there is a thermo siphon flow issue. The fact that it heats up normally at start-up makes think that it’s not a solid blockage but maybe air in the lines or steam. Maybe the steam displaces the water and then once the steam condenses it’s replaced with air. The inlet pipe is hot enough to make steam or be steam. Let me know what you think.

[@Wholelattelovepage]

Hey don, Would help to know the make/model of machine. I assume it's a machine with E61 group based on your description of inlet/outlet pipes. But is it dual boiler, HX or single boiler dual use? Unfortunately the PDF with logs did not come through with your comment.

[@donvincent1291]

@@Wholelattelovepage It is a Rocket Appartemento. I purchased it in December 2018.

[@DrakeLovett]

What kind of data do we have on brew temperature stability on a heat exchanger machine like the Profitec Pro 500 with a PID and a flow-control device? I have come across a lot of people who are raising some concerns because of how the heat exchanger operates, potentially getting the brew temperatures too hot due to the restriction of flow.

[@Wholelattelovepage]

Hi Drake, Thanks for the question. I have repeatedly tested the Pro 500 and other PID HX machines like Rocket Espresso EVO R and Type V using a Scace device and found them to be amazingly accurate with brew temps. There are certain cases like extra long idle times, odd ambient conditions or heavy use where there's some drift or a short flush may be required. Honestly I was stunned a few years ago when the Pro 500 PID first hit the market at how good it was. Really did not think it was possible and I was wrong. Marc

[@joacogaray]

With the thermablock, is the water in contact with the aluminum at all or it just goes through stainless steel pipes?

[@Wholelattelovepage]

Hi JG, Thanks for the question. Every aluminum thermoblock I'm familiar with has stainless steel water piping internally. Marc

[@putukawitra]

Do you have boiler classic gaggia with heater 220v

[@Wholelattelovepage]

Hi PK, yes we do: www.wholelattelove.com/products/alum-boiler-120-220-240-v-assy

[@toomasvendelin]

I make espresso only (no latte, no cappuccino, etc.). I want the best quality, but do not want to pay for the features I'd never use. What type of boiler/machine would be optimal choice in this case? Thank you for informative videos.

[@Wholelattelovepage]

Hi TV, If you are pure espresso then a single boiler machine is the way to go! You'll still be able to steam milk should the need arise but will not be paying for higher-end steaming capabilities. Here's a video comparing a range of single boiler machines: kzbin.info/www/bejne/l5vZhqqIj5plaqs Marc

[@longpvo]

hey mark, can you do a video on flow control with HX boiler with PID (Cronometro R).

[@Wholelattelovepage]

Hi LPV, Thanks for the request. While flow control is not an original purchase option on Rocket machines I know some do install it. But, different vendor's FC devices work a little differently with flow rates based on valve opening positions. If you installed an FC on your Cronometro R I advise calculating your flow rate at various valve positions. Here's an article on how to do that. It also has graphs of 5 flow profiles based on flow rates: www.wholelattelove.com/blogs/articles/intro-to-calculating-flow-rate-on-e61-group-machines Rotary pump machines generally have much higher potential flow rates than vibration pump machines. ECM/Profitec rotary pump machines using ECM or Profitec FC devices can do near 30g/s with the FC wide open while stock flow rate on those same machines is 10-11g/s. Not many situations where you'd want to go too far beyond stock flow rates. Majority of profiles reduce the stock flow rate like those using long low flow pre-infusions for lighter fresh from roast specialty coffees. Here's a video covering 2 easy flow profiles. It's done on the rotary pump ECM Synchronika. Although a dual boiler machine it should be similar to your HX PID Cronometro R: kzbin.info/www/bejne/l160coKlbbuaa6M Marc

[@longpvo]

@@Wholelattelovepage Hi Marc, I am actually really interested to know how and if FC affects brewing temperature stability with HX Boiler w/ PID (not HX Boiler w/ brew group PID like Lelit Mara X).

[@yveslemmens5384]

With a prosumer grinder and espresso machine at home for mostly weekends, and during the week drinking most coffee at work, which working method would you recommend? grind at home and put a gaggia classic at work? Do you have other ideas?

[@Wholelattelovepage]

Hi YL, That's a reasonable idea but you will lose some freshness grinding ahead of time. Also likely to be difficult to get the grind size just right for the work machine. I suppose with some trial and error you could get there. Especially if willing to compromise a bit on the espresso quality at work. My best idea is a grinder at work next to the machine. If you go that route a couple of good parings with the Classic that are not crazy $$ are the Eureka Mignon Facile: www.wholelattelove.com/products/eureka-mignon-facile-espresso-grinder or the Bezerra BB005: www.wholelattelove.com/products/bezzera-bb005-automatic-grinder Hope that helps! Marc

[@yveslemmens5384]

@@Wholelattelovepage Thank you very much for your advice! Really appreciate it! You're the best :-)

[@MJ-nb1qn]

Great video. I have a 18 year old Pasquini Vivia 90 (pressure stat was upgraded and I believe it’s adjustable??). I have never descaled it but always use filtered water. My brew water temp is low. Do you think it is scaled up or should I try and adjust the pressure stat setting, or try descaling (someone advised that may dislodge big pieces)? Help please Any body! I do have my eye on a Rocket 58! But should I look at PID HX? Thanks

[@Wholelattelovepage]

Hi MJ, Thanks for the comment and questions. 18 years with no descaling? Since I do not know your source water hardness or type of filtration there's no way of knowing for sure if you have scale. Very few water filters do much of anything to reduce mineral level. Vast majority are simple particle filtration plus activated carbon. Those type have little to no affect on water hardness. Unless your source water is very soft (low in minerals) to begin with it's probable you have some scale build up in the machine. That said, I think you would have had issues from scale many years ago. For low temp you could try adjusting the pressurestat. I believe your machine has a boiler pressure gauge. Note the pressure it reaches when fully heated now. Then adjust pressurestat to raise pressure by 0.1 - 0.2 bar and see if that makes a difference. If the machine is severely scaled descaling after so long could dislodge chunks and cause issues. But if you are planning on a new machine maybe nothing to lose? R58 is a fine machine. Latest version of that is the R Cinquantotto: www.wholelattelove.com/products/rocket-espresso-r-cinquantotto-espresso-machine Their PD HX Cronometro machines are nice and available in plumbable/rotarty pump EVO R or reservoir/vibration pump Type V. Both come in either Mozzafiato or Giotto case models. Hope that helps! Marc

[@MJ-nb1qn]

@@Wholelattelovepage - Thanks a bunch. The water is filtered, RO, ultraviolet light treated, then they add a little Calcium so it isn’t flat. Sometimes the machine thinks it’s out of water as it won’t conduct. The pressure gauge is almost to to Max setting range. People say my shots are the better than shops around town! So I must be doing something right. I’m going to order a new grinder soon. Same rotary for 18 years too. I have had the Pasquini apart a lot replacing pressure stat, switches, 3 pumps, a transformer, gaskets, seals, etc. I just rebuilt the motor on the grinder. I’m 65 and think why not have the finest! Why doesn’t Pasquini make machines anymore? If they do they’ve hid them. Thanks so much.

[@krzysztofkrol663]

I have a questions what can be problem when one boiler machina do not give proper presure on coffee ekstraction its about 3bar only?

[@Wholelattelovepage]

Hi KK, Low brew pressure can be cause by a bad pump or a blockage - usually limescale in the machine's internal plumbing. Marc

[@chun914]

what about the heat up time of different boilers?

[@Wholelattelovepage]

Hi Kai, That's an excellent question. It varies a bit based on machine make/model, type of brew group, boiler volume, etc. but here are some generalizations. Thermoblocks: 1-2 minutes Single boiler: 5-15 minutes Heat-exchange: 15-20 minutes Dual boiler: 20-30 minutes Marc

[@george_taylor]

The heat exchanger, as I discovered recently, is a lot more complex that you covered there. You should do a video going into the need for a well calibrated HX and the use of a restrictor value to slow own the thermosyphon.

[@Wholelattelovepage]

Hi George, Thanks for the comment. You are correct, thermosiphon restrictor sizing is critical for temp accuracy. Recent crop of PID controlled HX machines do well. Over the years we've been very involved with manufacturers testing and providing feedback on a variety of details including restrictor sizing. Marc

[@george_taylor]

@@Wholelattelovepage Marc, a few months ago I picked up a 2nd hand E61 which I've renovated. However idle temp is 100C+ and I need to flush out a cup+ of water, and immediately extract, to get the temp down enough for decent shot. I've not taken it apart yet to check the restrictor as I'm waiting on some teflon rods to cut to fit with different sized holes drilled in the hope I can figure out the optimum size. Writing/Reading on a few of the home barista forums this seems to be a big topic that is regularly re-visited. Would love to see a video covering this by someone.

[@echthroi9]

Now do the Manument Leva!

[@eosme]

for the thermal aluminum block type would that be like the breville barista express or the barista pro?

[@Wholelattelovepage]

Hi e, Thanks for the question. The Barista Express uses a thermoblock boiler. The Barista Pro uses what Breville calls aThermoJet Heating System. It's similar to a thermoblock in how it operates. Marc

[@eosme]

@@Wholelattelovepage thank you Marc for the super informative video. so would a lever machine like an izzo alex leva and pro800 be the HX type of boiler?

[@Wholelattelovepage]

@@eosme You are welcome! The Pro 800 is similar to an HX boiler in that 1 boiler heats water for steam and brewing. It's a little different in that it has what's called a dipper tube running from the boiler to the group and not an independent isolated heat exchange section feeding the brew water. The boiler itself has a very large connecting surface to the massive group to transfer heat. There's an excellent graphic of the setup over on home barista: www.home-barista.com/reviews/profitec-pro-800-review-t44660.html Marc

[@adambromley6972]

Are the double boilers and pressure heat exchange boilers commercial? Do they have special electrical/water intake setup to function? Or are these types of boilers included on a normal home machine you could plug into a wall outlet?

[@Wholelattelovepage]

Hi Adam, Depends on the machine. There are commercially rated machines using HX and dual boiler setups. For instance all four of the Crem One machines featured in this video are commercially rated: kzbin.info/www/bejne/m4qrdK2krLJgpKs Although commercially rated they are commonly used in home setups. Many similar machines are not commercially rated. They're often classed as "prosumer" level machines. Most use standard power. Some can be plumbed direct to waterline. Marc

[@adambromley6972]

@@Wholelattelovepage extremely helpful thank you!