Delonghi Ecam 23.450S heating up please wait
'heating up please wait...' and that's it, suggests a fault with either a sensor or a control board... and in today's market, who could ever guess which?
I'm sorry this is far more philosophical than technical. I really hate to say this. Still, if any half-way modern appliance has given you 15 years' service, what more would you have expected?
Traditionally, you would have taken any faulty gizmo to a local repair expert, who would have fixed it for a charge greatly less than any replacement cost.
Today, it's almost inconceivable that the cost of even diagnosing, let alone fixing any fault would be comparable to the cost of replacing (whatever) with a new one.