Breville Dual Boiler BES920 steam boiler not heating

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

#1: Post by Isaac97 »

Hi there,

Just picked up a BDB BES920 for a steal because it wasn't heating properly. I assumed it would be an easy enough fix which i think i was correct on because seals and everything were gone and it needed a good clean, i was getting there with diagnosing all the problems thanks to this forum.

In the process of a descale i accidentally left the drain screws open and now the steam boiler doesn't heat and is cold to the touch. When I try the steam wand i just get three beeps in response.

I have tried resetting the machine to no avail. I fear i may have fried a fuse. If anyone has any suggestions on how to proceed that would be greatly appreciated.


#2: Post by luvmy40 »

More than likely, you burned the in line thermal link to the steam boiler heater. A fairly cheap part but a fairly difficult repair. I do beleive there is an easy way to do a continuity check without completely disassembling the machine. I'm sure someone posted up a video or step by step on the repair at some point.


#3: Post by luvmy40 »

BTW, this is exactly the reason those in the know recommend using scale free water and never running the descale program on the BDB.

Isaac97 (original poster)

#4: Post by Isaac97 (original poster) »

It definitely was the thermal fuse, managed to replace it and it's able to heat up, though very slowly in at this point. The last person didn't look after it very well hence the clean and a multitude of problems to fix first.

User avatar

#5: Post by lancealot »

congrats, thats one of the more challenging repairs.

Handycap Horus

#6: Post by Handycap Horus »

Hey! Just came across this and have the exact same problem, 3 beeps, no steam boiler heating up. I have gone about deconstructing the machine andddddd - Blue thermal fuise fine with a continuity check, white sleeved fuse on boiler side - failed continuity check.

I think this means that the white sleeved fuse has gone - so hopefully a simple replacement...

I have attached and Image of teh fuse in question. I also notices that the temerature sensor (I think?), had some gunk buildup where it connected to the boiler. Not sure if it's something wrong like corrosion or if it's just a oil left over for sealing? What would you say?


#7: Post by pedini89 »

Hey Horus! How did you go replacing your thermal fuse? Did it solve your problem? I picked up a leaky dual boiler with a broken steam boiler last week for cheap and am in the process of diagnostics. I have fixed the leaks and found the steam boiler fails to heat. I'm thinking it also has a blown thermal fuse, the process of getting the the fuse to check it with a multi-meter is pretty daunting, did you find an easy was to do it? Or am I just going to have to try and suck it up and take everything apart to check?


#8: Post by B1ueN0te »

I believe I have the same issue, it happened in the aftermath of a routine descaling. The brewing section works fine butI am getting 3 beeps and no steam. By opening the right descaling valve, some water is coming out but it is not warm.
This issue is the subject of several publications but still, I was not able to fix it so far:
- the engineering reset did not make any good (ref Julien Seemuller, Youtube)
- disconnecting the red wired probe to help the boiler to fill with more water, with the hope that water would rince the probe (ref Dylan's Home Espresso Bar, Youtube, "Breville DualBoiler ...")
- after the engineering reset, I have not error message coming up

The next step would be to test the thermal fuses for open circuit, but they are out of reach. I have seen some people (ref Kanan Coffee LLC, Youtube, "Where are the NTC or thermal fuses on Breville Dual Boiler 920xl") able to test them without a full disconnection and unmounting but do not know how to get there (I found 3 screws, I guess they are more of them).

Should I check other things, before the deep digging ? Any tips for checking the thermal fuses ?


#9: Post by luvmy40 »

It's been a while since I replaced the steam boiler thermal fuse, but I remember being able to track the wires to a spot where I could disconnect one and make a continuity check without pulling the boiler. I wish I could remember where to tell you to look.