toekneeoeeo, sorry for late reply, I'm sure you found a solution by now, but I believe my new thermal fuse came with crimps to apply. So... this fix may only work a few times before all the original wire is eaten up. That's why I say cut as close as possible on the original. Don't go around blowing this fuse too often!

elcaboing, I assume you also have long since fixed your problem but a higher rated thermal fuse just melts at a higher temp. There would be more risk of permanent damage to other parts of the machine if too high a temp. I'm not sure what the highest safe temp would be.

pcrussell50, I just came across your mention in the BDB repair thread while looking for some advice on pump and group head leak repair. Quite honored that you called this "heroes work"!! But I must correct you on one point. I am a woman!

Also, yes, this machine suffered a long period of leaks at my workplace. Once I took it home, the first thing I did was replace all leaking o-rings. But I was never able to remove all the hard water accumulation inside. It was only shortly after I took it home, I'm trying to run my first descale, that I blew the thermal fuse. It had been working for a few shots without leaks just before! Imagine my frustration. But all leak free now. Just other common maintenance problems to deal with...

Very well done, sticking with it. Do not run the descale function any more. It is too risky. Most high end machines (probably all) don't have a descale function. Instead, they expect you to use scale free water. That's what all the shops do, and there is no reason we all can't do it.

-Peter

Hi. littleyip, Thank You for the very good WiKi how to change the Stollar's BES980 Steam boiler. I got exactly the same situation, I had to change the the steam boiler and Your example was very helpful. And Yes - the root cause was thermal fuser - it had melter during descaling process. But I have another question - maybe somebody knows the answer:
My BES980 machine asks to descale it very often. During the boiler changing process I made look inside it. My Steam boiler looks like new inside and outside: no any scales. So I have changed the boiler and assembled machine back. I put new water filter. On the next day it asking to descale again. So I know I can descale it once again, but I am sure, that in a day or two it will ask me to descale again.
I would be so grateful if somebody would tell where could be the root cause. Maybe it has some broken sensors? How the machine decides that it needs the descale? Reset procedure does not help, Firmware version is A15.

Thanks for the detailed description - I learned a lot about these machines from it.

I had a similar problem with the machine (BES980XL) only heating to 160F after replacing O-rings. Went through enough of the steps in this post to be able to see the boiler terminals from a hole in the bottom of the machine and managed to clip a couple of alligator clips on the terminals. I determined that the thermal fuse and boiler element were fine.

Where the problem turned out to be is the thermal fuse on the smaller boiler above the group head. After searching to find a diagram of the water circuit for this machine, it made sense that this smaller boiler was the problem as the hot water was coming out tepid but if I ran it for a while it got hotter (as it seems that it passes through a heat exchanger in the steam boiler before going into the smaller boiler).

The thermal fuse on the second boiler is much easier to change than the one on the steam boiler - with the top cover removed, it can be seen slightly to the left of the front side of the boiler when looking from the front of the machine (the fuse is covered by a white plastic tube). It can easily be popped out of its holder, replaced, and put back into the holder without and further disassembly of the machine.

So I assume that after draining the boilers and replacing the O-rings, I ended up with an air pocket and the boiler overheated and blew the fuse. I cannot think of any other reason as it was working fine before (except for the steam boiler leaks).

As for the steam boiler leaks, it appears that when this happens, the triac board gets wet and some or all of the solenoid valves start rapidly switching on and off. It seems that when the board gets wet, the triac board outputs around 85V to the solenoids when they should be off. This actually continues even after the machine is turned off and will only stop when the machine is unplugged. The board on one of my machines obviously got permanently damaged and now one of the solenoids never turns off.

If you see steam coming out the back of the machine, change the O-rings before it causes permanent damage.

johnwlee wrote:So I assume that after draining the boilers and replacing the O-rings, I ended up with an air pocket and the boiler overheated and blew the fuse. I cannot think of any other reason as it was working fine before (except for the steam boiler leaks.

That was a great, informative write up. Thanks for sharing.

One comment here that you should look into: Your air pocket theory is fine as far as it goes, however the boiler should have water level sensors that should prevent heating if water is not detected. So it's possible that either your sensor is fouled by mineral buildup, or you have water that is overly pure and is thus not conducive enough for the sensors to read.

-Peter

Hey everyone. In need of desperate help here. My oracle was working fine(or so I thought) and then one day I heard a "POP". Now the steam wand doesn't do anything. In hindsight, I thought I heard some hissing or sizzling coming from the oracle sometimes but figured it was just something I just didn't notice before. When I opened it up to change the thermal fuse (assumption on my part) I saw that a steam boiler line had been leaking. The 4mm line closest to the steam wand solenoid ( back corner behind boiler). I went through the process and found the thermal fuse has near zero resistance. What am I missing. What could be faulty??

Hello friends, I would like to ask for an advice. I followed the procedure of changing the fuse, and I think i did it right, after assembly pumps start to run, but I have realized, that even though, machine is turned off, on the steam boiler is a voltage. Is it normal? Have you any idea, where I could make a mistake? Thank you very much.

Just registered with Home Barista in order to say a huge thank you to littleyip. Just followed her instructions and successfully changed the fuse (which I found on eBay - 5 for £4). The repair took me around 3 hours, though a chunk of that was because I dropped a clip inside the machine.

The only bit that didn't work (entirely my fault) was pulling out the brown wire so that I could change the fuse. While I'd clipped off the two cable ties holding the lower pipes on, I didn't then remove the pipes! However, this led me to using a pair of sniped nose pliers to unthread the wire brown fuse through the inspection hold under the boiler. On reflection, this turned out to be an easy option and I will probably do it the same way the 'next time it blows'..

Another tip, if I may. To avoid having any screws left over, I assembled a collection of around 10 jars, into which I put the screws/clips/bits for each of littleyip's photos/stages, along with a brief note. So, thankfully, no screws left over at the end.

This repair isn't for the fainthearted, but it is absolutely doable.

Littleyip, you've saved me a fortune! Many thanks again.

Tony