Breville Dual Boiler o-ring replacement: what size?

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
sqroot3

#1: Post by sqroot3 » Apr 20, 2019, 1:23 am

I've read a few conflicting things about what size O-rings are necessary for the BDB, and I wanted to buy a bunch before I take off the top and start working.

A lot say to use 007 O-rings for the tubing going into the boilers. But the sensor holes seem to use a slightly bigger blue ring, at least based on some videos I've watched. Does anyone know what size those bigger rings are?

Thanks!

pcrussell50

#2: Post by pcrussell50 » Apr 20, 2019, 10:49 am

The sensor rings are MUCH bigger than -007. So much bigger that they can't be confused or interchanged with them. They also rarely need changing. Late this year will be eight years with BDB's and I've never had a sensor o-ring go bad. Though I have heard of people with a sensor itself falling apart... Though rarely.

Anywhere you see a PTFE water tube, is where you will use a -007 o-ring. Over time, they will leak for sure on the steam boiler top. And less frequently, if at all, everywhere else you see PTFE water tubes.

HTH

-Peter
LMWDP #553

Vinny-L

#3: Post by Vinny-L » Sep 11, 2019, 3:19 pm

Does anyone know where to source one of those washers that go with the o-rings? I seemed to have lost one.
Thanks

pcrussell50

#4: Post by pcrussell50 » Sep 11, 2019, 3:28 pm

I do not...

But there are reports form years ago when we first started re-o-ringing, of people who just ignored the washer. It should re seal without it even if it may need a new o-ring sooner than later for lack of the washer.

Also, you can order washers of the correct outer diameter, and then widen the hole out to 4mm with a 4mm drill. Not too hard if you're reasonably handy.

So for now, get yourself back in business by ignoring the washer, and decide what to do later.

-Peter
LMWDP #553

mrjag

#5: Post by mrjag » Sep 12, 2019, 12:13 am

One of my sensors sprung a leak so I'm on the hunt for replacement blue o-rings. A quick check with the calipers has me thinking that they are #010 fluorosilicone o-rings, similar to those found here: https://www.theoringstore.com/store/ind ... ucts_id=21. Sadly a bag of 100 is going to run $26, compared to the $6 for the smaller red silicon o-rings. Yeah, I know I don't need 100, but I'd like to have a handful of spares for down the road. I'm happy to match the existing material if it matters, but I can't figure out why they didn't stick with the same material given the much lower cost of the red silicon o-rings. The application is practically the same.

Both materials are similar, with silicon having a slightly higher heat resistance and fluorosilicone more resistant to fuels and oils. Can anyone think of a compelling reason to pick the fluorosilicone (blue) over silicone (red) material?

Here is the exact part that I'm thinking of replacing the larger blue o-rings with:
#010 https://www.amazon.com/gp/product/B000FMWNX0/

Here is what I previously used for the smaller red o-rings:
#007 https://www.amazon.com/gp/product/B000FN0WYG/

User avatar
Jake_G
Team HB

#6: Post by Jake_G » Sep 12, 2019, 7:53 am

I would recommend Aflas.

Aflas is specifically engineered for hot water/steam applications and has excellent abrasion resistance, resilience and high temperature stability. I replaced the O-rings in my check valves and vacuum breaker in my GS/3 with Aflas and have had zero issues this far, but it'll take a year or two before I know for sure that they will outlast silicone or Viton. By all accounts, they should.

Cheers!

- Jake

pcrussell50

#7: Post by pcrussell50 » Sep 12, 2019, 11:26 am

The inspiration of the "Slayer mod" to the BDB speaks! ;) *

Jake, before he repaired his GS/3 probably looked at the application charts for o-rings and discovered (as did a few of us a few years back when we first started doing this repair ourselves), that despite widespread use in various espresso machines, neither of the common o-ring materials, Viton or silicone are an ideal match for the application. Breville used silicone anyway, most likely judging it as "good enough" on balance. A few guys doing their own research decided that EPDM was a closer fit than the other two and went that route with good results. I have advised newbies over the years to use either Viton or silicone simply because they are easy to get, and cheap, and because of this, it gets them back in business right away, thereby building confidence in their machine and skills. I usually include the disclaimer that the o-ring might not last as long, especially if you install silicone without a little dab of food safe grease. Since the job is exceedingly easy, I'm OK doing it every other year or three. Heck even if it was once a year, I'd be fine with that, the job is so easy.

But...

I'd be fascinated to see how durable the Jake-optimized solution is. So you guys should do it. I'll probably order up some myself, even though I won't have any leaks to deal with for a while, just to have them ready.

*Jake was the one who gave me the idea to re route the Breville tubes through the onboard needle valve, to create full pressure profiling. And furthermore, on mine, I'm no longer using the stock Breville needle valve, but a different one that... you guessed it... was specced out by Jake. We call it the "Jake valve". Pretty creative, eh? ;)

-Peter
LMWDP #553

Vinny-L

#8: Post by Vinny-L » Sep 12, 2019, 2:46 pm

Specifically im having issue with the steam boiler refill o-ring assembly. without the washer, it is leaking with just the silicon o-ring. however it may also leak if i had the washer too, its hard to see down there, and hard to tell, i tried to squeeze 2 o-rings but it was too thick. It definitely has some scale buildup from the water, i can try to drill my own washer, but does anyone know of a thicker o ring that may work?

pcrussell50

#9: Post by pcrussell50 » Sep 12, 2019, 2:53 pm

Are you sure you couldn't stack two soft silicones and press the tube in firmly enough to flatten enough to get the clip through?

I'm sorry I can't be of more help. I have not had the issue with the side fill for the steam boiler. This is a fairly rare one, though not unheard of.

It's been a while since I had to replace a "top of the boiler" o-ring... IIRC some of them had the washer and some didn't. Refresh my memory... Does the washer go on top of the o-ring or under it? My latest version -920 doesn't use the o-ring and clip system for the water tubes on the tops of the boilers. Breville went to something else (tube nuts) in early 2018.

-Peter
LMWDP #553

BaristaBob

#10: Post by BaristaBob » Sep 12, 2019, 3:16 pm

sqroot3 wrote:I've read a few conflicting things about what size O-rings are necessary for the BDB, and I wanted to buy a bunch before I take off the top and start working.

A lot say to use #007 O-rings for the tubing going into the boilers. But the sensor holes seem to use a slightly bigger blue ring, at least based on some videos I've watched. Does anyone know what size those bigger rings are?

Thanks!
Kev,

I used the 007 o-rings last time I did a repair...that was for the tubes going into and out from the steam ball valve. Also from the ball valve into the steam boiler. I had a pack of the #006 but they seemed too small, the #007 was the better fit. That's the only repair I've had to make in over 3 years now. Just popped the top yesterday to take my 6 month routine look inside and everything looks shiny and new all around...no water spots or unusual marks.
Bob "hello darkness my old friend..I've come to drink you once again"