Breville Dual Boiler leaking steam from water tank valve - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
WWWired
Posts: 352
Joined: 5 years ago

#11: Post by WWWired »

Ounick wrote:There is some corrosion on the top of the probes. I thought it was just solder to connect the wire to the probe.

Well maybe it is solder. I don't know, but would that cause the steam vibe pump to be always on?
Awesome new views Ounick :) . . . and a fantastic mystery that OP Ounick appears to have located the culprit for through great fault narrowing!

A very unusual situation where steam appears free to come and go through what should be a one-way-street in the Steam Pump haha! The smaller OPV on top of the Steam Pump only blocks return flow from the drip tray (rather unnecessary haha) but it does serve to provide an over-pressure relief outlet for the entire Steam Hydraulic System if it exceeds the designed pressure limit. In post 6 above, the considered fault path for escaping steam was in the Brew/Coffee Hydraulic Pathway and a possible failed Brew/Coffee OPV, but further great investigation by OP Ounick, has narrowed the fault to a likely issue with the Steam Pump not maintaining seal on the forward piston stroke, creating an open channel to the Water Reservoir port that connects the Water Reservoir to the water inlet feed line to the pumps. Here is an amended version of the annotated Patent drawing in Post 6 above, this time showing the identified fault pathway (red highlighted) as narrowed by Ounick . . .


Note: Given the updates, it may be worth considering whether it might overheat components if the machine is turned on too long as it appears from further descriptions that the Steam Boiler is not full enough to to touch the Water Level Probes (see 256 in diagram above) and cause de-energization of the Steam Pump and the more it runs, the more the Heating Element will be exposed (due to water vaporization and water level continuously dropping slowly) and it is at risk of overheating and burning out that Thermal Fuse (different than the white Thermostat) on the side of the boiler (at about the same level as that white Thermostat in the recent photo's that looks ok). More of a concern, it could damage the Heating Element or the NTC Sensor at the top of the Steam Boiler. It appears from all descriptions and Ounick's brilliant fault tracking, the removal of the Steam Pump (the smaller of the two pumps on the right when looking forward from the back of the machine), disassembly and inspection of its components. It may be that it is just clogged with mineral scale or some debris but the videos below will show how to get it apart (when disassembling, go very slow and watch out for that tiny ball in the pump haha! . . . if that gets away it might take a bit to find it).

That Thermostat on the lower 1/3 of the Steam Boiler looks ok but there is a thermal fuse at about the same height on the side of Steam Boiler that can fail permanently Open circuit if heating exceeds the designed thermal range (shutting off the Heating Element completely to protect components from heating damage). These two thermal control components on the lower third of the side-wall of the Steam Boiler are pretty tough to get at so its worth considering not operating a Dual Boiler when there is any evidence water is not being transferred to a boiler and in this instance until the Steam Pump is inspected perhaps.

To have steam back flowing through the Steam Pump (the smaller of the two pumps) it would have to beat two check valves possibly (one for sure, two if including the connector between the Water Reservoir and machine-feed port). The first is the Steam Pump itself. It is possible this is why the Steam Pump is always running as well. If the Steam Pump is not forming a seal inside the pump it may not be pushing any water and worse, as noted in OP's great troubleshooting, it might be allowing steam to pass back from the Steam Boiler to the Water Reservoir fitting (the one the OP has circled and labelled with "Steam" in the photos of where the Water Reservoir should slide in). The Water Reservoir itself has a check-valve that should not allow anything to pass back into the Water Reservoir. This would not stop the intrusion of Steam back into the chamber where the Water Reservoir goes necessarily as Steam could reverse direction, as Ounick wisely points out if it is beating the Steam Pumps check-valve, and escape around the Water Reservoir Fitting perhaps into that cavity that the Water Reservoir seats into.

There is no question this reverse passage through a pump would be quite a feat haha and a very unusual situation but would explain why the Steam Boiler can't pressurize and why boiling/vapor/steam production is occurring at much lower temperatures than the Steam Boiler should permit if properly a fixed-volume pressure vessel, sealed on one end by the Steam-Pump's mushroom and ball check-valves and internal o-rings, and on the other end by the Steam Boiler's assembly that provides Steam when called for. The pressure inside the Steam Boiler should be above 1.1 Bar and the Heating Element will be de-energized when the Temperature/Pressure is high enough. But if the Steam Pump is allowing an opening to the worlds atmosphere of 1 bar and therefore the pressure/temperature cannot get high enough in the Steam Boiler:
  1. The Heating Element would just keep being energized since the excess pressure/temperature/steam is being shunted back through the Steam Pump and into the Cavity where the Water Reservoir is inserted via the Water-Reservoir water-feed-connection.
  2. And more importantly, as observed by Ounick, the Steam Pump would just keep running as it isn't pushing any water into the Steam Boiler and therefore the water level never rises high enough to touch the Water Level Probes to shut off the Steam Pump.
Definitely incredible observations by Ounick and brilliant Photos and video! A unique situation and one that is sure to not only assist many in future relating a large number of possible issues but has incredibly explained in photos and video and Ounick's diagnostics how these brilliantly engineered and designed Breville Dual Boilers work! :) :)

It looks like it might be worth removing the Steam Pump (the smaller of the two pumps) and disassembling it and inspecting it). Some annotated photos will be added here shortly showing the Steam Flow, but in the meantime, here's a few videos of how to disassemble a pump by Milen Stoitsev, a rather brilliant YouTuber, who has many incredible videos for anyone who would like some fantastic insights into several machines and components . . .
Here's one of the annotated fantastic photos by Ounick . . .

Ounick (original poster)
Posts: 7
Joined: 1 year ago

#12: Post by Ounick (original poster) »

WWWired wrote:Awesome views Ounick :)

Note: Given the updates, its good not to run the machine too long as it appears from further descriptions that the Steam Boiler is not full enough to cause de-energizing the Steam Pump and the more it runs, the more the Heating Element will be exposed (due to water vaporization and water level continuously dropping slowly) and it is at risk of overheating and burning out that Thermal Fuse (different than the white Thermostat) on the side of the boiler (at about the same level as that white Thermostat in the recent photo's that looks ok). More of a concern, it could damage the Heating Element or the NTC Sensor at the top of the Steam Boiler. It appears from all descriptions and Ounick's brilliant fault tracking, the removal of the Steam Pump (the smaller of the two pumps on the right when looking forward from the back of the machine), disassembly and inspection of its components. It may be that it is just clogged with mineral scale or some debris but the videos below will show how to get it apart (when disassembling, go very slow and watch out for that tiny ball in the pump haha! . . . if that gets away on you it might take a bit to find it).

That Thermostat on the lower 1/3 of your Steam Boiler looks ok but there is a thermal fuse at about the same height on the side of Steam Boiler that can fail permanently opened (shutting off the Heating Element completely) and getting at these components is not easy so try not to run the machine until that Steam Pump is inspected perhaps.

To have steam back flowing through your Steam Pump (the smaller of the two pumps) it would have to beat two check valves possibly (one for sure). The first is the Steam Pump itself. It is designed to move back and forth and in one direction it takes in water and and the other direction it just slides the piston backward. It is possible this is why the Steam Pump is always running as well. If it is not forming a seal inside the pump it may not be pushing any water and worse, as you suggest, it might be allowing steam to pass back from the Steam Boiler to the Water Reservoir fitting (the one you've circled and labelled with "Steam" in the photos of where the Water Reservoir should slide in). The Water Reservoir itself has a check-valve that should not allow anything to pass back into the Water Reservoir. This would not stop the intrusion of Steam back into the chamber where the Water Reservoir goes necessarily as Steam could reverse direction, as Ounick wisely points out if it is beating the Steam Pumps check-valve, and escape around the Water Reservoir Fitting perhaps into that cavity that the Water Reservoir seats into.

There is no question this would be quit a feat haha and a very unusual situation but would explain why the Steam Boiler can't pressurize and why boiling is occurring a much lower temperatures than the Boiler should normally allow for it was properly also a fixed-volume pressure vessel, sealed on one end by the Steam-Pump's mushroom and ball check-valves and internal o-rings, and on the other end by the Steam Boiler's assembly that provides Steam when called for. The pressure inside the Steam Boiler should be above 1.1 Bar and the Heating Element will be de-energized when the Temperature/Pressure is high enough. But if the Steam Pump is allowing an opening to the worlds atmosphere of 1 bar and therefore the pressure/temperature cannot get high enough in the Steam Boiler:
  1. The Heating Element would just keep being energized since the excess pressure/temperature/steam is being shunted back through the Steam Pump and into the Cavity where the Water Reservoir is inserted via the Water-Reservoir water-feed-connection.
  2. And more importantly, as observed by Ounick, the Steam Pump would just keep running as it isn't pushing any water into the Steam Boiler and therefore the water level never rises high enough to touch the Water Level Probes to shut off the Steam Pump.
Definitely incredible observations by Ounick and brilliant Photos and video! A unique situation and one that is sure to not only assist many in future relating a large number of possible issues but has incredibly explained in photos and video and Ounick's diagnostics how these brilliantly engineered and designed Breville Dual Boilers work! :) :)

It looks like it might be worth removing the Steam Pump (the smaller of the two pumps) and disassembling it and inspecting it). Some annotated photos will be added here shortly showing the Steam Flow, but in the meantime, here's a few videos of how to disassemble a pump by Milen Stoitsev, a rather brilliant YouTuber, who has many incredible videos for anyone who would like some fantastic insights into several machines and components . . .
video
video

Here's one of the annotated fantastic photos by Ounick . . .
image
I took it apart last night and think this was the issue.

I decided to just buy another steam pump from Ulka. I got the exact NME1S model because I didn't know if other models could be used.

Additionally, every time I remove the steam pump (this is my second time, first time I didn't take the pump apart completely) the hose on the bottom ends up braking off at the top front the zip tie.

Any idea or recommendation on hose replacements for it? You can see my makeshift solution with electrical tape because if it brakes again I won't have enough length to attach it anymore.




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WWWired
Posts: 352
Joined: 5 years ago

#13: Post by WWWired »

Brilliant! You got it! haha! I'm trying to figure out what exactly that little bit is there haha! Is it debris? :)

Regarding The feed line, from the Y-splitter to the Steam Pump that is being considered for replacement, will check around if there are any specifications on that hose but if you have a ruler (caliper is most accurate, that online electronic bay place sells them for $10 bucks), the outer and inner diameter is what is important (in millimeters likely as these machines are Italian/Australian measurements).

As this leg of hose is not carrying either high-temperature or high-pressure water, food-safe Silicone Hose should be suitable and Teflon Hose is not needed.
*EDIT: Appears from Data Sheets the input port on the NVE 1s Steam Pumps are ø=5mm, although this may not be the hose's inner diameter. It might be worthwhile to grab a caliper/ruler and see if a measurement of the hose's inner and outer diameters is possible. The maximum pressure in any part of the Steam Hydraulic Pathway should never exceed 3 bar (if it was a high pressure hose, such as after the Brew Pumps higher 9 to 15 bar, a hose might need be Teflon, Copper, Brass or Stainless to withstand these higher pressures and avoid exceeding the lower burst pressure ratings of silicone hoses).

ryry
Posts: 24
Joined: 3 years ago

#14: Post by ryry »

I just wanted to say this thread was awesome. Excellent analysis and annotation by WWWired!

Herman B
Posts: 1
Joined: 5 months ago

#15: Post by Herman B »

I own a Solis Triple Heat (BES920 / Type 1011) espresso machine. This is the exact same machine as a Breville BES920. Last week, I had a water leak at one of the connections on top of the steam boiler. The water leak caused a ground fault. The problem was quickly resolved by replacing some o-rings on the head of the steam boiler.
However, while disassembling the machine, I noticed a piece had been cut out of the original silicone connection hose (D) at the bottom of the steam pump (F). I am attaching two pictures of the original connection hose (D). The machine worked perfectly with this hose.
Since I did not understand why a piece was cut out of the connecting hose, I replaced the original hose with a new one without the piece being cut away. And also this way the machine works perfectly ?!
My question: does anyone know why a piece was cut away in the original hose? What could be the purpose of this? Or is it a manufacturing error?
The bracketed letters D and F refer to the numbers in one of the annotated fantastic photos by Ounick further in this thread.
Many thanks in advance for your response!


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