There is too much water in the boiler so it can never get to steam temperature. It has been overfilled past the max line or not properly drained when anti-calc cleaning.
Wait for it to cool down then empty it completely over the sink. Tip it upside down and wave it about, it you can!
When you plug it back in, try it with half a tank of water. Everything should be back to normal!
(Why don't they put this in the manual? It is a very easy mistake to make.)
Helpful John
March 2011