Breville Dual Boiler Mods and Maintenance

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#1: Post by pcrussell50 »

latest edit, 8 May 2022: I added a second paragraph to item 6 under the maintenance section. It is an ifixit guide to removing the group and the steam boiler. This has application if you have an older BDB and want to upgrade to the latest group with the two-piece collar inserts that are chap and easy to replace. Also, because it involves removing the steam boiler, it should provide easy access to the thermal fuse in case you melted yours during a descale gone bad. Don't descale. Use good water. ;)

edit, 29 March 2021: If it hasn't become obvious, I am dialing back my participation on HB. Hopefully this guide continues to be mostly useful to people in the superb community of BDB users. If you are having problems that cannot be addressed by this guide, or by the excellent community here, you can try reaching out to me by email (my HB username) at gmail. I might continue to update and add to this guide as I discover new things. In fact I am working on something right now which is pretty exciting for the DIY maintenance and mod space. That one I will share, after I have perfected it. Beyond that, we will just have to see.

edit, 9 March 2021: Added subsection 1A, about clearing the persistent, "descale" message if you are one who uses safe water and doesn't descale

edit, 20 September 2020: scroll down to Mods, "Plumbing and conversion to rotary pump", The new gold standard guide to going rotary

edit, 3 September 2020, scroll down to the bit about plumbing and rotary pump. I finally added the process with parts and pics, in the rotary BDB thread I started

edit, 29 July 2020, added the bit at the end of item 3 about the one o-ring that's a bit of a challenge, included the link to Geoff Chapman's great writeup

edit, 21 July 2020, Chris/Lancelot figured a way to the the non-Slayer, pressure control mod without water wasting

[edit, 20 June 2020, the link to steam valve seal flipping procedure

So, I was going to put a bunch of helpful links to mods and common maintenance (which is oddly about all that ever seems to be necessary on these machines to keep them running), on the first page of the: Breville Dual Boiler, five+ years on which has kind of become a de facto "BDB owner's thread". But Dan suggested that since that thread was already huge, maybe I start a new one, with a bunch of helpful links on the first page.

I expect this to be a work in progress in case anyone else who is a marathon BDB owner discovers the so far elusive, big unfixable problem. So here goes:


What you will face going forward, (and this applies to any machine you may one day have in your espresso journey): Any machine that deals with hot, pressurized water, in the presence of electricity, is going to have certain maintenance requirements. There are generally two philosophies in dealing with this. Preventative maintenance, and "fix as you go". Breville is very much a "fix as you go" type of company, and thankfully, waiting until something breaks rarely comes with any kind of serious damage on this platform. The only pitfall is a psychological one... By not doing preventative maintenance, things will break. And when things break, people tend to think their Breville machine is junk and seek something else. Then they spend four or five times as much for something else, where you do expensive yearly PREVENTATIVE maintenance, so that things don't break (as often). And guess what? Then people are even more certain their Breville is junk. But this is a big logical mistake of course. And leads to incorrect conclusions and beliefs about the durability of these machines. In reality, if you treated your expensive machine like you do you BDB and do no maintenance at all until something goes wrong, you would be in for (a lot) more money and more downtime than you would with a BDB. Alternatively, you can also maintain your BDB as you go, and possibly never have a problem... At least as far out as eight years, since these machines were introduced. There are no 20 year old BDB's so we don't really know what happens that far out.

All maintenance and repair begins with removing the top cover: See: "Removing the top and accessing the innards" here: ... 603#716603 Once the cover is off, don't bother trying to disconnect all the wires from it. Just find a way to prop up the cover out of the way, without straining the wires.

USE SCALE-FREE WATER. IOW water with no or very little calcium or magnesium (the components of scale). Or water with low enough Ca or Mg AND a pH that prevents scale formation. See this post: Breville Dual Boiler Mods and Maintenance. And this thread: This is what to expect from good water

1a) So you shouldn't descale because you don't need to, because you should be using good water
BUT the "descale" message shows up in the screen and stays there during warmup, (it goes away once warmed and ready). If this bugs you, I found out how to clear it. And it's not using any of the menus you are told about in the instruction manual. It is in the menus for service and diagnostics that they don't tell you about. This one, to be exact. So scroll through all 12 stored codes and the next will be the "ErSt" (error reset?) Anyway, with that in the display, press and hold the "manual" button until it beeps and blinks and is reset... As per step 5 in the outwest link. This will clear the stored codes, AND clear the stored "descale" message.

2) Drippy steam valve
video of seal flipping procedure:
The steam valve on all these machines eventually develops a slow drip when warmed up. Sometimes in as little as a year, sometimes two or three. There is a thread here on HB discussing all about it and before we figured out how easy it is to fix, a bunch of posts about possible solutions. Cutting to the chase, the easy, no parts fix: Breville Dual Boiler ball valve detail, pics. If you don't ever want this to happen to you, pretend it's a La Marzocco or other high end machine and flip the seals every year. As with other BS myths about proprietary non-user-serviceable parts, you can also buy replacement seals on Amazon for next to nothing for a bag of 100. ... UTF8&psc=1 But by and large, you don't need them. Just keep flipping the ones you have.

3) You need new o-rings when you get: GFCI tripping, runaway heating, steam tubes hissing, water puddle under machine. These are all caused by the same thing... the o-rings on the boiler tops letting steam pass and wetting the control board under the lid.

O-ring servicing and replacement: Breville Dual Boiler, five+ years on

Sounds terrible. "This machine is a disposable appliance grade POS" Right? Wrong. Has nothing to do with faulty electronics. The electronics on this machine are actually amazingly robust. And Easy fix, almost free. OR easily preventable if you choose that route by changing your o-rings every year or so like La Marzocco. What is happening is that common silicone #007 o-rings sealing the 4mm PTFE water tubes into the top of the steam boiler need replacement. Once the insides dry out and you have fixed the leaks with new o-rings, normal operation resumes. A bag of 100 of these size #007 o-rings is $9.99 on Amazon. Your children will be dead of old age before you run out. Detailed thread: ... 603#716603 How about a less detailed but still very informative thread that shows how NOT-intimidating this is? Here: Breville Double Boiler leaks & o-ring replacement

Bit that's nice to know: Since early-mid 2018 Breville changed the method of sealing the PTFE water tubes on top of the boilers to some other scheme that looks more robust than the o-rings. We do not know when or if they will leak, or what to do about it if they do. Too early to tell for these newer machines.

When you do the o-rings, do NOT drop or lose the hairpin clips that hold the tube in the boiler or you will have to interrupt your repair to go to the store and get more. If you do, "7/32 hitch pin clip external" from the big orange home improvement chain are reported to work.

A challenging one lies here: Some people have reported that they get a hisser on the side of the steam boiler. Enough in fact, that it sounds like more than a fluke. I never had it in a six year run with my old -900 but maybe I got lucky? The challenge here is that the tube and clip holding the o-ring are in a tight spot that is hard to access. Based on Geoff Chapman's writeup which I will link shortly, you should probably get some longish hemostat forceps off Amazon, and be prepared to remove the solenoid to gain more working room. I won't cry a river for you over removing the solenoid though. It's easy, and should be done every so often anyway as part of routine inspection/checkup. Anyway, here's the link to Geoff's excellent writeup: BDB Steam Boiler Port Repair, Lower Side Wall I will add one thing... I do use the tiniest little dab of silicone grease, not on the o-ring itself but on the brass knob that has to slide into the fitting on the side of the boiler.

4) The solenoid?
Starts getting "buzzy" for some people after two or three years. Might be due to scale. I remove and inspect mine about once a year. But I use scale free water so not had any problems or cleaning to do under the base of the solenoid. If you need to replace it, Open the cover and direct replace. But a new one here: ... 39484.html This is a standard Lucifer base solenoid, so any other Lucifer base solenoids should work, too like the one from the Silvia.

5) The pump?
Rarely needs replacement. But As with other BS myths about proprietary non-user-serviceable parts on the BDB, it uses the same Italian Ulka vibe pump as any other prosumer vibe pump machines out can also buy replacement pumps on Amazon for next to nothing. ... 00NMNA138/

6) Steam boiler won't heat?
Usually the $2.00 thermal fuse melted out, (which saves the actual boiler heating element). AFAICT, when this happens, it is most often because of a descale process gone wrong. See item number (1) a few numbers up from here. The part is cheap, but the job is kind of big. HB member "littleyip" did heroes work changing one out on his Oracle. Now, the Oracle is a much more complex cousin of the BDB, so I would expect it to be an easier job on the BDB. Still nobody I know of has done as good a writeup on the job as "littleyip" in this thread: Breville Oracle BES980XL Thermal Fuse Replacement/Detailed Disassembly Normally, I would recommend people to pay the $350 and send their BDB back to Breville for this repair, banking on them not wanting to do the job and sending out a brand new machine. But recently we heard from somebody who paid the fee for this repair and actually fixed it instead of sending out a new one. So keep that in mind.

I have just become aware of an ifixit guide to removing the group and the boiler. This should give you access the thermal fuse for easy replacement. Their guide says it's a 45 minute job, which frankly, I thought would be much longer, so I consider this to be good news. The ifixit guide.

7) When is it time to send away to Breville for service?
The answer to this is subjective and dependent on the user's interest and ability. I have my thoughts and I will share them with you. First of all, they are not kind sweet gentle, bend over backwards. That's fine. You will be fine if you know how to fit what you need, with what they are capable of. First the way it works: After establishing contact with Breville, and deciding a repair is warranted, they will offer to charge you a fixed fee. For me, it is $350. I've heard that somewhere along the line for newer customers, they began charging $400. This includes shipping both ways, and if you didn't keep your box, they will send you one (which of course adds a little time to the whole process). The box is pre fitted to the machine, so you don't have to worry about shredding up newspapers to make your own padding. Just print the prepaid Fedex shipping label they email you, and drop it off at FedEx and head back home. Their policy is three days at the shop maximum, and if they can't fix it, they send you a new or factory refurbished machine, and include a six month warranty. The good part is, they only want the bare machine. You keep the portafilters and steaming pitcher and all accessories. If they send you a new machine, you will also get another full set of accessories. My thoughts: I think they use a coatract service, and I don't think they are game for any bigger jobs than you or I. I also don't think they have much more access to spare parts than we do. For easy repairs like o-rings and steam valves, I would NOT send away. It is too easy to do this yourself. They will take your money, do the easy job, and send your old machine back to you. Bummer. BUT... for bigger jobs, (which in reality are quite rare), I don't think they want to pay people in Southern California, a Southern California wage to fart around on a tedious job. They will just send out a new or factory refurb. More good news... I think they are perpetually out of factory refurbs. Almost ever case I've heard of where they didn't fix someone's machine, they sent out a brand new one. This is what I got, in the one case in eight years that I punted to Breville. And even at that, I could probably have fixed it myself. (My machine stopped pre infusing, and changing the pump, which I did myself, didn't fix it). I think a capacitor was blown on the computer. The either didn't have any spare computers, or they didn't want to do the job. So I got a brand new machine.

These are pretty much the only common items that wear out and need repair. One more general catch-all thread for repairs: ... nes/726101

Another way geeky, tech rich source if you really want to bury yourself in this topic and learn special key combos or break out a multimeter: ... ir-guides/


in progress... links to follow text. check back later

Flow and Pressure Profiling

In order to keep this post from becoming huge, I expanded this section in a different post of this thread: Breville Dual Boiler Mods and Maintenance

Three ways:
1) Straight out of the box, this machine already has programmable pre infusion. This is more and better than almost all of the high end machines on the market. And it has full manual override of time. So if you want to pre infuse not according to a pre set time, but rather, until is "looks right", you can do that too.

2) If you want more, you can move a microswitch out of the way and get current model conical valve GS/3MP style pressure profiling, in which the excess is vented to the drip tray. Not very elegant, but it works. A few posts down, here: Breville Dual Boiler Mods and Maintenance
On EDIT: Chris/Lancelot has come up with an elegant upgrade to this method, where the water does not get wasted into the drip tray. And it's easy too. Three cheers to Chris. Here is the link to his writeup: Another Breville Dual Boiler flow control mod.

3) If you want to go whole hog, you can do what we call the "Slayer Mod", which gives you beginning to end flow control, without venting/wasting to the drip tray. This is actually better-than-Slayer level control over flow. (2) is so easy it's a joke. You can't really even call it a mod. This one (3) is just easy. A few posts down, here: Breville Dual Boiler Mods and Maintenance

Plumbing and conversion to Rotary pump
Easily done, with no permanent changes to the machine itself. About as easy as installing an under-sink softer filter and plugging it's output into the pump, then running that to the back fo the BDB. The difference in quietness and refinement cannot be understated. A HUGE aesthetic upgrade. Here is the thread where I detail it: My Breville Dual Boiler now plumbed with rotary pump

The new gold standard guide to going rotary:
My Breville Dual Boiler now plumbed with rotary pump

Brass OPV and brass necked pump
Breville Dual Boiler Mods and Maintenance
If you aren't ready to commit to plumbing, (which must be done to go rotary), the brass necked pump and brass OPV give a much more refined, damped, and quieter sound and feel. Nowhere near rotary level. But something.

This video demonstrating the rotary pump AND flow control. About halfway through the pull, I speed the flow up and towards the end, you can see I slow the flow down (the way everyone should as the puck erodes... If your machine has the capability):
LMWDP #553
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#2: Post by Quester »

Awesome. Thanks for posting this.

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#3: Post by mr2andy »

Great stuff!!!

pcrussell50 (original poster)
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#4: Post by pcrussell50 (original poster) »

(First, the crude and easiest way...the MUCH better, "Slayer mod" method to follow in a different post)

Flow and Pressure Profiling EXPANDED WITH PICS AND VIDEO ITEM (2) The pressure bleed/GS/3MP method
(the MUCH better, "Slayer mod" method to follow in a different post)

2) If you want more, you can move a microswitch out of the way and get current model conical valve GS/3MP style pressure profiling, in which the excess is vented to the drip tray. Not very elegant, but it works.

The way this works is, you bleed off pressure during the pull by opening the water tap. This sends the un needed water through the tap and into the drip tray in much the same way as the GS/3MP with the conical valve. In order to have full authority, you have to remove the top cover and move the microswitch from behind the water knob. This is super easy.

here it is under the two partially loosened screws:

remove the screws and pull out the switch and the holder:

here is the switch. on mine, I just zip-tied it out of the way:

video of it in action. with stock vibe pump. you can catch glimpses of the extra water going out the tap into the drip tray:
LMWDP #553

pcrussell50 (original poster)
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#5: Post by pcrussell50 (original poster) »

And now the big dog...

Flow and Pressure Profiling... THE SLAYER MOD

With this one, you have direct control of flow and pressure at the puck, from the tiniest trickle, all the way up to full flow potential of the pump and anywhere in between. It's this second bit, the bit about anywhere in between that is actually something Slayer can't do. Slayer has "two speeds" high and low. With this mod to the BDB, flow is continuously variable anywhere you want in between. And as different from the "GS/3MP mod" above, there is no excess water wasted when you are not using full flow. It all goes through the puck... just at any flow rate you desire.

So, how do you do this? Not quite as much of a no brainer as simply moving the microswitch. But not much worse. It is a simple plug and play re route of a couple of the existing PTFE tubing, and cap off an unused water line. No cutting or permanent modding. All easily reversible put back to stock for factory repair if you should ever need it.

First, from post #160 in the BDB Slayer Shots thread, my eureka moment when I first did it: Breville Dual Boiler "Slayer shots"?

Skipping ahead to post #165 the textual description of how you do it: Breville Dual Boiler "Slayer shots"?

How it looks under the IMS screen, going from slow, to super slow, to open (before conversion to rotary):
How it looks on the group pressure gauge pulling a shot with a long Slayerlike pre infusion, slow ramp, then slow decline (also before conversion to rotary):
Pics of the tube routing: Breville Dual Boiler "Slayer shots"?

Improved way of capping the unused water line: Breville Dual Boiler "Slayer shots"?

And finally the coup de grace...Andy's video of the mod (note in the video, he had not yet moved the microswitch of the water knob, which is the first thing you should do):
LMWDP #553
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#6: Post by Valo_Soul »

Just wanted to send a huge, sincere thank you. Excellent post!

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#7: Post by gchapman »

Thanks for this, Peter, and for all your pioneering work. A great help to all of us BDB owners.
Geoff Chapman

pcrussell50 (original poster)
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#8: Post by pcrussell50 (original poster) »

Re water and it's importance to durability...

If your yearly inspection of your solenoid doesn't look like this, you need to address your water situation:

This is five years worth.

LMWDP #553

pcrussell50 (original poster)
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#9: Post by pcrussell50 (original poster) »

From post #1

Brass OPV and BrassNecked Pump

First, just a few minutes ago, I took out my brass OPV and brass pump and put the stock one back. Why? Because I'm now plumbed in and using a rotary pump anyway these days, so by putting the stock pump and OPV back, I'm more ready when/if it comes time to send the machine off to Breville for a repair/free new machine.

No washers, just brass on brass and plumber's tape

Here is a thread with pics, detailing a guy's conversion to brass pump and OPV. Breville Dual Boiler BES900XL brass OPV and pump mod.

Some things to add:
1) I decided not to use the compression fitting he used, and used a QC or PTC (quick connect or push to connect), because since the tubing is PTFE, in a compression fitting it may eventually cold flow and fail. My fitting is the black elbow with the blue lip, 1/8 BSP brass threaded into the OPV

2) I did NOT use any washers in between the pump neck and the OPV. Just Teflon plumber's tape.

3) a big one... he had issues with rust inside his machine. He clearly had leaks from old o-rings. You should inspect for leaks yearly. If no leaks, replace the o-rings every other year anyway. You will have a machine you can eat off of, it will be so clean.

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#10: Post by klund »

I'm replying to 1. get notifications on this thread, and 2. to say "thank you!" for continuing your yeoman's work for the BDB community. I've spent most of my online time in the 3D printing and board game communities, and since my BDB was last replaced this spring, I haven't had any issues to worry about. Well done!