Saeco Exprelia HD8854/16: Recurring Error E04/E05 Despite Motor & Micro Switch Replacement

Hello,
I’m having a problem with my Saeco Exprelia HD8854/16 coffee machine, which I’ve been using at home for five years.
The machine displays error E04, sometimes E05. The error does not disappear after unplugging it, but after leaving it switched off for a longer period – a few days – it can start working properly again. Unfortunately, after a few or a dozen or so coffees, the error reappears.
I asked a friend who is a repair technician to fix it; he replaced the motor. The machine worked for two days and then the same thing happened again; the technician gave up. I sent the machine to the Saeco service centre in Warsaw; they replaced the microswitch. The machine worked for about two weeks and then E04 appeared again. After sending it back to Warsaw, they said it worked for them and the message only appeared once. They replaced the seal on the unit and sent it back. The machine worked for two days (it made maybe six coffees).
Has anyone else encountered this fault and could offer any advice?

Best regards,
R.

A standard complaint and not many websites can deal with it.

There is a drain valve that leaks, not large spills almost unnoticeable.
However, a little bit of water gets on the flow meter and it causes this defect.
Replacing the valve and flow meter itself repairs the situation for year two.
Personally, I recommend replacing the valve but the version from older constructions that are clearly more durable.

During the six-year use of this machine, it has recently happened to me for the third time. I would not be able to handle myself because I was constantly switching off and on the machine but without a result. Disgusted I sat down to the computer hoping that something I will find on this error (E-05). I found at least a page where there were descriptions of these errors: https://www.p4c.philips.com/cgi-bin/cpindex.pl ? ctn = HD8761 / 01 & dct = QAD & faqview = 1 & refdisplay = E38_MINUTO2_ERRORCODE_103884 & refnr = 0103884 & scy = PL & slg = ENG
At "my" error I found this description:
[i] "E05 (flow meter / boiler / pump):
When air enters the system, perform the priming procedure. In case of failure, the error code 05 will appear on the display. The following solutions can help you manually remove air from the system.
Remove and re-insert the water tank several times while the device is on. Make sure that the water tank has been inserted correctly.
If there is a filter in the water tank, remove the filter, and then turn on the device. "Unfortunately, it did not help, and my husband, who knows a little about such mechanical things, asked me to make some space for the coffee machine and give it 5 minutes." We took out the whole water tank and into the place where the filter connects to the block it poured a bit, about 10 ml of water. The inserted tank, the display told us that the water is filling the circuit and ... everything started to work as it should !. Because the code E-05 means: (flow meter / boiler / pump ) it turned out that the air got in there, it circulated and there was no reaction. I would like the "procedure" to be helpful.

Any more solutions with the E05 error code?