# Dual Boiler Leak



## Jiiim (Jan 5, 2016)

Hi,

My Dual Boiler has started leaking from the bottom left of the machine. After it's been on for about 40 minutes, a small pool forms by the front left foot, which looks like it is running from under the drip tray area.

Anyone else had this?

It's still under warranty, so I contacted Sage and they said to de-scale as that could be a cause. But I live in a very soft water area and have never had to de-scale any other appliances, so I'd rather not buy the chemicals and go through all the faff if there is another solution.

Cheers,

Jim


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## 4085 (Nov 23, 2012)

Just tell Sage it has nothing to do with a descale. A leak is a leak or you could always tell a little white lie......who really cares!


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## DavecUK (Aug 6, 2013)

Descale it and it will most likely leak worse


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## Jiiim (Jan 5, 2016)

Yeah, I'm not that keen on the idea TBH. They told me to descale it anyway.

Perhaps I should just take it back to John Lewis?


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## Dallah (Jan 31, 2015)

Take it back for replacement.


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## kazemik (Nov 17, 2013)

I would avoid the descale, as there is always a chance you could damage the machine, I did manage to break my machine trying to descale mine one time. I must Sage customer support did help me out even though machine was out of Warranty at the time and were very helpful. The instructions do not state that machine needs to be cold when you start the process, so if you do descale it ensure the machine is cold when you start.

I would take it back to John Lewis and make it their problem.


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## Beanosaurus (Jun 4, 2014)

I reckon it's a leak from the main boiler, probably emanating from a perished silicon gasket.

But yes, get it repaired/replaced under warranty!


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## michaelg (Jul 25, 2013)

See my reply to the other thread here about Sage pushing the lack of a descale as the cause of all problems with the machine. I had a leak twice and the 2nd time the PID seemed to fail. I think they're just told to say this at their customer service as maybe it is a cause for people in hard water areas.


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## yakima (May 14, 2015)

My BES920UK (dual boiler) had an intermittent leak to the left front side of the machine but I thought it may have been a slight amount of water running over the back edge of the drip tray when i run hot water through the group head between shots. Finally, last week the machine became very hot despite it not being switched on (only on at the wall socket). After trying to initiate a 'clean me' cycle the machine tripped the main fuse box in the house!! After phoning Coffee Classics Ltd, who are the repairer for Sage machines, they said it sounded like an internal leak or failed seal. My machine is almost 4 years old. This will be the second repair of this machine as the first was a faulty needle valve.


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## Goblinsgrind (Feb 9, 2014)

In case anyone comes across this thread looking for info' on SDB group head leaks, the group collar inserts in the SDB are made of soft rubbery plastic, it holds the portafilter in against the group head seal and is not fit for the purpose it's designed for. It will eventually fail and cause a leak from the group head. 
Sage/Breville now refuse to sell owners replacement internal parts as they say they fear owners personal injury! The part costs 83p and is relatively easy to replace but instead owners are now forced to send their machines to Coffee Classics for repair at their own expense if out of warranty. 
I have replaced a collar insert once only for the group seal to invert on a back flush, stupidly I forced the portafilter back into the group resulting in a crimped group collar insert. Luckily I had a second spare but despite successfully installing this it continued to leak so next step is to try a new group head seal and failing that it's off to Coffee Classics for my SDB?


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## ajohn (Sep 23, 2017)

@Goblinsgrind Maybe you are talking about an early design. They did have set up that broke and changed some part to metal. But yes part 3.7 looks like it's made of some plastic / rubber. Stuff like that could last a very long time as the flex is taken up by the grouphead seal.









3.7 forms a stop to allow the portafilter to only rotate one way and also provides the ramp to tighten it. There is a rather long thread on the DB on another forum mentioning faults over time and I can't recollect any mention of it failing.

They did have a set up that finishes up very similar to the 54mm machines. I understand these did break on the DB at times but seem to be ok on the 54mm machines. Odd really as those run at a higher pressure. Maybe down to area. This was fixed by replacing plastic with metal as far as I can see. Think there is a video on youtube of an early one being fixed.

Can't really understand the problem you had when you replaced it. Grouphead seal inverting doesn't make much sense, installing the wrong way round might explain problems and would need a lot of force to fit the portafilter, also if that happened before the first time it leaked. How old is it?

It's called a collar insert for group collar.

John

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## ajohn (Sep 23, 2017)

That parts diagram is out of date by the way. There are now screws going into the bottom of the rim of the grouphead.  Stick your head on the drip tray and look up.

John

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## Goblinsgrind (Feb 9, 2014)

Hi John,

Thanks for your reply. Your right it's the 3.7 collar insert for the group collar and does exactly as you described, Coffee Classics were aware of the part required which suggests it's not all that uncommon and here is the link I used how to fix it.

https://www.ifixit.com/Guide/Breville+Dual+Boiler+(BES900-BES900XL)+Group+Head+Collar+Insert+Replacement+Guide/40279

I also remember reading when it happened and was trying to find information on it, on another forum, HB I think, that owners were saying be gentle with how far you turn/lock in the portafilter to increase its longevity and were bemoaning its availability as a replacement part.

My issue after a successful replacement was following my back flush routine. I had backflushed after a shot and the group seal was seemingly sticking out (this had happened before) partly visible, but being first thing in the morning with my shot all prepped I stupidly tried to simply push it back in place whilst twisting the portafilter which engaged the lugs but without the proper space and consequently knackered the group collar insert.

So I replaced the damaged group collar insert (which is not strong plastic) and it still leaked/still leaks, I know it's fitted correctly because I had previously replaced it no problem and did the same again so now I'm hoping that the leak is possibly the group seal being worn and old. Whether this should be the culprit I don't know.

This all happened about a year ago btw and I've just been too nervous/worried/ depressed/busy to try sorting it, resorting to French Press - no espresso.

I'm going to order the group seal and hope that sorts it but am just wondering whether I should try and get the 3.5 part above that holds the shower screen as well, if not fitting just right could it perhaps cause a leak under pressure? Problem is that's out of stock from Sage.


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## ajohn (Sep 23, 2017)

Not sure about the ifixit as early models used a plastic part to form the ledge the portafilter lugs rest on. It may have had the collar as well.

The newest parts manual I managed to find is 2014. It doesn't match my machine in this area. Looking up at the base of the group head there are several screws - no way am I undoing them but suspect it might allow the collar to be replaced without touching the boiler. The screws hold a chunk of what looks like stainless in place - usual shape to allow the portafilter to go in and the collar sits inside it. Changing it that way isn't much different to cleaning behind the shower screen 4 screws rather than 1.

A tube which is part of the body sits around that with stainless trim on it.

Manuals seem to have dried up past 2014 so assume this mod came later. That's why I wondered how old your machine was* ???*

If something was sticking out it suggests something went wrong replacing the collar. Can't imagine what as it doesn't make much sense to me. The grouphead seals can go hard and also can harden up if the machine isn't used. They are harder as supplied as well but tend to slacken off with a bit of use. Silicone doesn't change so much as rubber.

The bit above is the grouphead heater. Don't think there is anything else. The way they seem to have done it is the whole assembly including the boiler is metal - that is then attached to the body. Screws through top and bottom parts could do that as well eg the screws I mentioned.

Part 3.4 might be an assembly of 2 parts with screws like mine.

To be honest one thing I have always thought about this area is so what if they have to do it providing costs are sensible. Their engineer reckoned sent to them was £20 per hour and visits £25 - *supposed* to cover travel costs. Words he used. A problem could be Sage's call centre dreaming up prices. I'd try getting an idea from CC. They told me they can provide part numbers. A different machine could be bought with the same features but when I look I usually come to the conclusion 2x the price or more as I would want commercial volumetrics.

However I suspect you have this one. They need the number on the label to tell.

https://spares.bigwarehouse.com.au/images/files/56615_74db63937352e9eb5cc796d2849b4c60.pdf

No screws where I mentioned on these - part 3.4

John

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## Goblinsgrind (Feb 9, 2014)

The Sage DB I've got was bought in 2014 and was bought as new but secondhand and is MODEL BES920UK. Incidentally the group collar insert was already slightly damaged on the left lug ramp but performed perfectly well for a couple of years, then it went leaky and I left it for a a good year or two, then fixed it last year as described to knacker it a week or so later ?

I'm sure your rocking the updated group head with more screws etc. Mine is exactly as pictured on the ifixit.

I know the group collar insert is seated correctly as once it drops into place it's difficult to impossible to get it in the wrong way, and initially worked fine.

But it's a good point you raise about the group seal going hard and denuding over time with lack of use because it's been sat unused more than used in the past 6 years!

When I spoke to CC they said it was £25, or was it £50, per half hour plus shipping. Whichever, if I can't get it to work then off it goes otherwise I've got the most expensive worktop paperweight ever!!

I hear you on the specs, volumetric, pre-infusion and temp stability all great but I can't help think if I'd just gone with say an Izzo Alex Duetto or an R58 although I'd have paid probably a good £500 or more at the time new, less for second hand, I wouldn't have had this sort of issue! But shoulda coulda woulda is no good now and when it works again I'll be thrilled.

Btw some other issues I've read about which reportedly affected my model are running the descale program screwing the pcb, and CC told me the solenoids can need replacing.


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## ajohn (Sep 23, 2017)

The grouphead seal dropping doesn't make sense. It can't. Even the BES900 used the same arrangement. The spreader 3.5 in the pdf I linked to keeps it in place. Some have those split, probably due to over tightening the fixing screw. It just needs a bit of a turn when things firm up. As it's slightly terminal I bought a spare. If some one for some reason has changed this area it would explain your problems and probably the leak in the first place. Also a damaged collar.

My solenoid started rattling so removed it, dismantled it and cleaned out a bit of sludge on the valve seat with my finger. I don't think the machine tells people to back flush often enough. Some might say do it weekly. I've read that the engineers sometime replace the triac board as well as the solenoid. Triacs are pretty robust parts. Mains spikes might cause them problems so I plug into a surge suppressor. Not a bad idea when ever there are electronics about. Often built in as cheap but may not be.

The solenoid seems to be a standard part used on some commercial machines. The ones I have found so far have a bsp thread on the exhaust at the top and need a solenoid plug for connection. No stainless base like Sage use or costs go up an arm and a leg so would have to be brass. There maybe other problems such as port directions and the size and fit of the seals etc. Sage don't use O rings for this seal.

All UK machines seem to go by the name BS920UK, mine does so the number on the label is needed. No idea what you mean by rocking but do have an idea why the design seems to have changed. When I don't know.

It would be unusual to find parts that use O rings that can't be dismantled to replace them. Sage seem to use 2 grades of silicone. One is more suitable for sliding seal use but has lower temperature resistance. Probably best to use those if the O rings on the drain valves go or a better grade of viton - Viton have started putting a coloured dot on them so it's possible to tell which grade it is. Other makes come in a different colour. My drains were stupidly tight the first time I used them but that probably makes no difference to wear on these. The O rings on the boilers can be damaged if disconnected and then reconnected. Less chance if they are put on the tubes and then pushed back in. Best have some spares. Seems they usually last 3 years - at least according to reports. I favour a kit from Oz as it comes with spare clips. Handy if one is dropped into the machine. Think I have seen them in the UK at 40p plus postage each.

Level probes can need a clean. Seems to be the usual reason for the dreaded valve fault during descale - boiler wont drain. Well if it does people will know it's not blocked. I drain brew first to make sure it has drained. It's obvious that steam is draining. I suspect that descaling often enough solves all. From now on I am going to skip the first drain and leave the descaler in and run it for another 20min. Then save time on the flushes. The PID on steam now behaves as it should. No more loud boiling noises still about when steam is available. Gentle ones now for maybe a further 1 min. Problem with scale is that if it isn't all removed when the machine is descaled it will build up. Might be down to me or the previous owner.  Now I know what it should sound like I can try the machines built in time to descale indicator again but will still set it a couple of grades harder than our water is.

Machine choice depends. I and many others in the country can use tap water. For some that's not a good idea. I want a machine that is easy to descale. Another machine manual might say use hardness below some number and look in the boiler to see if there is any scale every 12 months. Descaling usually needs spanners and removing the boiler. I don't mind looking every 6 months to check for leaks even on the DB as I haven't refitted the lid fixing screws and have bit of cane to prop the lid up with. No need to leave it dangling on leads. Not sure when I will replace all of the boiler O rings - wait for a leak or replace at some time interval. Same with the grouphead seal. I also want stainless boilers.  So Sage has it's advantages and one disadvantage that could be bad. All machines need a servicing schedule or wait for something to go wrong and all will have some machine specific bits in them that will cost. Then there are people who wont self repair. On tap water all will generate scale. Suppose rather regular filter changes can prevent that but time interval is a rather woolly subject.

John

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## ajohn (Sep 23, 2017)

Whoops forgot one, found buried in an obscure place.

No more steam following a descale or during it etc but same could happen to brew. Not sure if it was a software fault that was about for a while or dirty level probes cropping up at an unfortunate time during descale. End result a beep when steam is selected meaning water isn't hot enough after it's had time to heat up. If all is ok steam will be available as soon as brew is ready. Some say steam needs a little longer to avoid the beep. Scaling maybe ? pass.

In short boiler heating come on with no or insufficient water in the boiler during descale. This results in a thermal fuse blowing. It wont be on a board it will be on the boiler. The heater may survive the experience. This seems to have been around when Breville did sell spares so some time ago. They also used to have several sets of detailed descaling instructions for different machines on their web site.

My first refurb had this problem on the first power up and boiler fill. I was told to descale the steam wand even though I had the beep. That can be done during descale. All I do now is let a bit of water come damp steam come out a few times during descale. The pump on this machine made all sorts of noises due to pumping air for some reason and I left it like that for some time. No problem with the replacement.  If this sounds like it's happening best turn off but sorting a thermal fuse might turn out to be relatively easy. A heater wont be.

Please bear in mind my authoritative style posts come from thinking about things, coming to a conclusion and sticking with them until I find a reason to change them.  Relates to what I did for a living. I see the collar like this - will it happen etc or why it might happen.  I'm favouring the why's a bit at the moment not totally though.

One thing that can also be said about some Sage machines is that thermothingy ones are more prone to scaling. The answer is pretty obvious. On the other hand Davec has mentioned that he doesn't have some of the usual problems because he used rehardened RO water.  You wont see him using Sage. All can come to grief one way or the other, make doesn't matter in this area.  I haven't used @dave.... etc as he might be busy.

John

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## Goblinsgrind (Feb 9, 2014)

Apologies for the late reply John, changed phone service provider last week, thanks for the posts they're really very useful, I will be powering my DB back up with the lid off next week for a diagnostic on Monday, decided I will get a group seal any way from Sage and I know the collar insert looks okay but I want to properly examine the leaking, if it is my collar insert that's damaged then it's my last one and I can't buy more, I do remember reading about someone looking to get them made on a 3D printer. I'll post you when I've done it


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## ajohn (Sep 23, 2017)

You may need the plastic part behind the shower screen if it doesn't look like this

https://www.sageappliances.com/uk/en/parts-accessories/parts/sp0020052.html

It holds the grouphead seal in place. Some have had them split -  Can't help wondering if due to overtightening and have a spare anyway.

John

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## Goblinsgrind (Feb 9, 2014)

Yes I was going to order one of those to be on the safe side and to offset paying the few quid postage for just the one group seal but they were out of stock of the it (black inner shower screen on website).

As I haven't ordered the group seal as planned, a job for tomorrow, I'm hopeful they'll be back in stock, thought I'd get a steam wand o ring at the same time given it's a only a quid.

I had a good look at my inner shower screen when it leaked, dropped it out with shower screen and the group seal and thought both parts looked absolutely fine but the black inner shower screen does look like plastic that could go brittle with heat and time


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## yakima (May 14, 2015)

Jiiim said:


> Hi,
> 
> My Dual Boiler has started leaking from the bottom left of the machine. After it's been on for about 40 minutes, a small pool forms by the front left foot, which looks like it is running from under the drip tray area.
> 
> ...


 Think I've found the probable cause of this left hand side leak. Although my machine had to go in for a complete set of O-rings replacing after four years (at a cost of £120) the *occasional* leak from the front left hand side continues. I am now sure it is due to the following poor design:-

if you lift the drip tray out and put your finger under the left hand side you will feel a round hole and a slotted hole - these are the exits which dump liquid when the group head relieves pressure or when backflushing. If you feel the position of the outermost round hole it seems mightily near the edge of the drip tray. My suspicion is that sometimes (dependent on flow) the discharge from this hole can dribble over the edge of the drip tray due to inaccurate placement, thus appearing as a leak on the left hand side. If the holes were moved a few more millimetres to the right there would be no problem and any discharge would be accurately placed over the aperture of the drip tray.


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## urbanbumpkin (Jan 30, 2013)

I've also started having the occasional leak from the left hand side of the drip tray.


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## urbanbumpkin (Jan 30, 2013)

I do hear the occasional his from inside the machine. Is there a simpletons guide to opening up the machine?


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## Rincewind (Aug 25, 2020)

...a piece of plastic/other araldited (other strong glues are available) in between the 2 holes should prevent this...act as a barrier or divergence ??


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## ajohn (Sep 23, 2017)

I'm on my 2nd and don't have this problem. A rather sever splash on the drip tray where it meets the main machine can cause water to escape to under the drip tray.



urbanbumpkin said:


> I do hear the occasional his from inside the machine. Is there a simpletons guide to opening up the machine?






Actually there is no need to remove the back plate. I use a length of cane as a "bonnet prop", much like cars did,

The earlier machine that didn't have the descale drains but otherwise much the same. Also what may be needed if scale builds up and descaling hasn't removed all of it.


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