# Sage Dual Boiler - Leaking descale valve O-ring



## Reggie (Oct 31, 2019)

Hi all,

I'm a new member seeking some help in sourcing replacement o-rings for a Sage dual boiler.

My machine is quite old and the latest problem that must be fixed (aside from the ones I can kind of live with atm - leaking steam wand, dripping hot water outlet and the random espresso boiler safety valve thingy malfunction) is the steam boiler descale valve o-ring. Below/attached is a photo showing both descale valves and you can see where the small black o-ring should be positioned on the steam boiler valve is missing.

I found the remains of this black o-ring in my drip tray when I drained the boiler after what I thought was a successful descale process. (Does anyone else seem to always create a new problem when they carry out regular maintenance with these machines?)

I have called both Coffee Classics and Sage who will not sell me the o-rings. Of course I can ship the machine to CC or pay for an onsite visit but I've already done the hard work here. Does anyone have any suggestions of where I can get these o-rings?

Whilst I'm there I'd also like to replace the green coloured o-rings also pictured and the blue o-ring that sits inside these valves. Whilst I have a few of the red and blue o-rings (thanks to Coffee Classics from previous visits) I don't have the green and black ones. In fact I've never seen the green and black ones before.

I'm also in two minds about replacing the machine. I've had it for many years (its actually a Breville DB that I bought across from AUS) and it could be time to move on. This repair would be my 4th in a little over a year. Its always something different and whilst I feel I am now competent enough to get to most problems, if sourcing the spares is impossible then maybe its time to upgrade.

I would greatly appreciate it if anyone can help me source these o-rings.

Thanks in advance!


----------



## ajohn (Sep 23, 2017)

It's hard to know what O rings Sage use but generally all of the ones on the boilers are replaced with red silicone. Blue suggests that they might be fluorosilicone. A bit odd on boilers in some ways. Green suggests they may be FKM O rings

https://www.frabo.com/eng/media-center/focus-on/differences-between-black-yellow-and-green-o-ring

Black some form of Viton - catch with that there are various grades some get up to FKM standards but black will probably the common one.

Biggest problem is that Sage could order anything they like in silicone with any colour so that they were easily identified and put in the right place.

Rather than trying to type out the properties look on the web. Where they may wear due to movement I'd use viton if the position is cool. Eg drain valve ends shouldn't get that hot but steam is a bit of a no no with them. FKM is better and silicone may well last longer than straight viton so they may be a special grade of viton.

It's fairly easy to identify the size of O ring. BS use different thicknesses to metric. On BS thickness goes up in steps. I'd guess this is why they are still used a lot. Metric tends to be much thinner in smaller sizes. Oddly in the engineering area we used to be a much more logical lot even on screw threads.

There isn't a valve on the brew boiler. The one on the steam boiler is likely to be an anti vacuum valve. It too will have an O ring in it. If that's acting up the boiler may be over filling which means the level sensors need cleaning. I've not seen an engineer do that so no idea what they do. Some have but "helpfully" don't comment on what they did. It probably involves cleaning the plastic part and the metal.

It might be worth you soaking the dismantled parts in the usual descaler solution. Not boiling but hot.

Sage tell people to descale the steam wand if they have problems with it. I have noticed that it's possible to get some rather wet steam out of it in descale mode. Hot water can only be done in normal mode. Something I think they have forgot. Some does get out of the group head when it's descaled which hopefully also cleans up the solenoid a bit. This may only happen when the brew boiler really has drained fully.

I'm pretty convinced that the built in descale indicator doesn't request it often enough. Engineers say once an month on the thremothingies. I've set mine a grade harder than the test strip suggests and may go a step harder than that. Do I change the filter often enough - probably not.

 All machines act up if they scale. The DB just adds O rings but they are easy to replace. You've just found some more.

Moving on is an interesting question. When the materials used inside are considered that's not easy. Descaling may not be either and often isn't. They go to some lengths to avoid water contact with brass and even exposure to aluminium is very limited. Scale and espresso machines just doesn't mix.

I'm also curious about the cost of engineer repairs on other machines is. Will it be cheap - doubt it. Maybe the greens will get their way and Sage will have to sell spares. Probably an entire steam valve or maybe they do replace O rings. I'd suspect the valve on all machines but could be wrong.

John

-


----------



## Reggie (Oct 31, 2019)

Thanks so much ajohn. Your reply is really detailed and helpful. I found a coffee machine and service company that appears to have similar sized and looking o rings in stock. Whilst they are listed for other machines the measurements look pretty close to what I think I need. So I'll see how I go.

Thanks again.



ajohn said:


> It's hard to know what O rings Sage use but generally all of the ones on the boilers are replaced with red silicone. Blue suggests that they might be fluorosilicone. A bit odd on boilers in some ways. Green suggests they may be FKM O rings
> 
> https://www.frabo.com/eng/media-center/focus-on/differences-between-black-yellow-and-green-o-ring
> 
> ...


----------



## Reggie (Oct 31, 2019)

Coming back to update what happened here. The o-rings I found online weren't quite the same size but close enough to work. So the machine lives on, for now.

Thanks again to John for your help. If anyone else needs to source Sage Dual Boiler o-rings in the future, please drop me a line.


----------



## ajohn (Sep 23, 2017)

A new O ring probably wont be the same size as a used one as they swell. Fortunately they are usually easy to find which series of O rings they are. BS type thicknesses go up in steps with size. Metric doesn't and thickness for size is generally different. Sage appear to only use BS.

I'd guess the O ring on the end of the steam drain is probably an exotic type as it's hosed down with steam every time it's used. As it's black it might be one of Viton's higher standard grades. I noticed recently that they are putting coloured dots on some of them. Really there should be a standard colour code and there does seem to be "after a fashion".

John

-


----------



## Freddieg28 (Dec 10, 2021)

Hey there pretty new to this site, I was wondering where/what o rings you got as I need to change mine of my dual boiler as steam is constantly coming out the tip.

cheers


----------

