With a delohghi magnica s I use descale button but see manual and milk jug errors come on flashing - wont start. Can I just run descaler through the machine using the hot water function to clean ??

SOURCE: descaling

I had this happen once and had to put it through the descale process again. Just put more water in the tank, try it again and see what happens.

Winesnob

SOURCE: Saeco Odea Giro descaling problem

Ok first check if the machine is in greenlight state when you press and hold the water button, as it will not work when the red exclamation mark blinking.

also check if the button work at all flipping back and forth to hot water and steam.
I have never had this problem that it dident work.
But remember this, you dont have to do the descaling again as that has nothing to do with the reset.
You can even reset the descaling alarm with out having done the descaling.

If that for some reason wouldent work I would think its the CPU card is not working.

SOURCE: descaling

(Button 26 is the right-most one (2 intersecting
ovals.)
From the Manual:
Press the button (26) for at least 5 seconds to
select the descaling operating mode; the LED
emits a fixed light.
• Direct the steam nozzle (14) toward the drip
tray.
• Position a vessel of adequate capacity under
the steam nozzle and turn the hot water knob
anticlockwise (16). The appliance starts an
automatic descaling cycle with pauses preset
by the manufacturer and managed
automatically by the appliance.
• At the end of the cycle, the flow of the
descaling solution is shut off and the 5 buttons
start flashing simultaneously.
• Turn the knob of the hot water nozzle (16)
clockwise to OFF. In this case, also the warning
light (27) flashes.
• Rinse the water tank and fill it with fresh
drinking water.
• Position a vessel of adequate capacity under
the steam nozzle and empty 2/3 of the
contents of the water tank by turning the steam
knob (16) anticlockwise; to shut off the flow,
turn the knob (16) clockwise.
• Let the appliance heat up and empty the
remaining contents of the water tank by turning
the steam knob (16) anticlockwise; to stop the
flow, turn it clockwise.

HTH
dave

SOURCE: Descale red light, wont go off, and can i use any delcale tabs

Solution: Just refill the water tank with water (no descaling solution) all the way to the "Max Line". Then run the full descaling program again --takes approx. 20 minutes. After the program runs completely you will get the yellow "standby" light on and the red "descaling" light will be off.

Next time you descale, be sure and fill your water tank to the "Max Line" before running the descaling program.
Hint: An incomplete cycle (not full tank) is what makes the red light stay on. In other words, it's staying red to tell you to run a full cycle (beginning with the water tank filled to the "Max Line"). Hope this tip is helpful!

SOURCE: Saeco Talea Giro Plus, descaling

Try doing another rinse cycle until water tank empties. I had to do that a couple of times, then the red exclamation mark came on. Then I turned knob to off position, refilled water tank, pressed the descale button for 6 seconds, green light came back on and it did its priming.