Saeco Moltio with error code 15

HiI have a Saeco Moltio HD8769/01, which is now almost five years old. This week the display showed the wrench with the number 15 when I started the engine, I googled it a bit and it seems to have something to do with the heating circuit. Here and in a few other forums there are already some things to do, but what I tried so far did not work. But since I can only solder a little bit and only have a superficial knowledge of electronics, maybe someone can help me here. I have already measured these two thermal fuses on the boiler and both have a passage. So they're still okay, right? Even if I unplug the plug that goes from the board to the boiler, there is only the error 15.my guess would be that the problem is somewhere on the board. On the triak I also made a continuity measurement (currentless). There is a continuity on the two outer pins, not on the middle one. Is that correct? What else can I test, or what could be the problem? Thanks a lot

Temperature sensor once measured?

How can I best measure it?
I just tried to measure at the plug, but I'm not quite sure if I can reach the contacts with the measuring tips. At least I can't get
a reading.

Even if I put a piece of twisted copper wire (from a loudspeaker cable) into the plug it shows nothing

.


Do I have to have a through hole there?

You have to set the multimeter to ohm. Don't know your multimeter now. Here are the values that should come out roughly.

The measuring device always remains at 0, or can I also measure on the sensor side if I really just can't reach the contacts in the plug? Otherwise I have to touch the plug somehow to be on the safe side. Or do I just get 0 as a value because it is broken.
But just to be on the safe side, we're talking about this thing called CLICK

Yeah, the feeler, I mean.
What kind of multimeter do you have and how did you set it up?

I only have a very simple one. It's not exactly that but almosthttps://www.directupload.net/file/d/5974/3gd29xqw_jpg.htm

Set it at 200k. And then see if you get a reading.

Now I put some more pins into the plug, then it works
at about 20°, 68 Ohm (fluctuates a bit). So it fits, right?

Yeah, that should fit. They're 68kOhms.
Just read in your first post you "tested" the triac. That's only not gonna work with a multimeter
.

I'd replace that. I think it's the one on the heat sink.

Yes, I had made a continuity measurement on the one on the radiator.
I had read in another forum that there should be no passage at the one contact. Is that
correct?

I'll see if I can get one tomorrow. It shouldn't be that expensive, I think you could test it.

There should be no passage outside to the middle. But it can also be that it does not shift and that is not so easy to check.

I just went to get a new triac. Couldn't find
one that
matched.

The original (Q8012RH5) has 12 amps, the one they had has

16 amps.


The exact designation is BTA16-800CW








.



Does it work or











not?




Or would it go to test and then change again afterwards?

Yeah, he's going. Just checking if the old one is isolated and the new one is too. Middle pin and the flag it attaches to. Otherwise a mica plate would still be necessary or useful.

Unfortunately no success
What values do I have to have directly at the boiler?