EQ6 continuous descale + steam out of machine

Dear all,

My inlaws own a EQ6 s300 coffee machine, which has just gone out of warranty. A few months ago they complained that it would ask for descaling already after some 20 cups or so. I performed a factory reset and it worked for a couple of weeks.
Then, the problem reappeared. I put the hardness to 'separate descaler' and the problem went away for a while.

Two weeks ago the problem came back again, but now with the added discomfort of a bang, followed by steam coming out of the brew group during startup. Since they are quite desperate they entrusted me with their coffee machine. After opening, I saw that an incoming silicone hose to the ceramic valve had a kink. I replaced it, though it did not solve the problem. After some mental preparation I decided to inspect the ceramic valve on the inside, but during disassembly the #$^#* connections of 2/3 pressure hoses snapped.
A little more surprising to me was that I could not find signs of clogging in there: both the disks and the channels seemed rather clean.

What is your opinion on this? Does the problem lie nevertheless in the ceramic valve and does it warrant replacement (some 65E)? Or is it perhaps the steam valve?

Thanks a bunch!

Best,
Andreas

Also, I should mention:

Before changing the tube, I tested the machine's working by making myself an espresso. It did not have a very strong taste, I think it tasted more like filter brew. After the tube exchange the taste had improved, but the steam release continued

If the connections of the ceramic valve are broken off, it is irreparable and must be replaced by a new one, the steam leakage may be caused by calcification, it should be decalcified with an amidosulfone-based decalcifier (e.g. Eilfix powder) and to dissolve the stubborn calcification with double or triple the amount of decalcifier.

I was already aware that I had to replace the ceramic valve

I am only quite sure that another decalcination will not solve the problem. I live in an area with very low water hardness and my in-laws already regularly decalcined the system. Especially in the last months they descaled some 6 times using Siemens descaler (so I guess the chemical you are referring to).

Is steam coming out of the bottom, the brewing unit and the coffee output (where the cup is) not a sign of anythign else malfunctioning?

Yes, can still be due to a defective water pump, defective NTC sensors on the heater or a clogged brew group.

Thanks for your answers so far!

I forgot to mention earlier that when I opened the coffee machine, I saw a drop coming out of the ceramic valve. It also appeared that this had been going on for a long time (slight chalk depositst). Is this normal?

Also, I followed your advice and checked the continuity of the pump and heater NTC (only one, and it seems a thermostat?). I only get inifinity / OC reading from the pump. Is there perhaps a fuse hidden in the heatshrink near the pump? I find it odd though, since the pump did work the last time I checked (although maybe not at full power), so it should not give infinite resistance... On the diode mode I get a voltage drop op 900 mV. Thermostat seems fine with giving a resistance of less than one Ohm.

So, in short: can the pump give infinite resistance and still function (partially)?

Anyone?