Depends what kind of machine you have, and whether this is new behaviour.
Normal heat-up times
Thermoblock: seconds. There is no reservoir to heat.
Single boiler: 10 to 15 minutes for the boiler, longer for the group head.
HX and dual boiler: 20 to 30 minutes for full thermal stability.
The ready light lies
It reports the boiler, not the group. The group head is a substantial lump of brass that takes considerably longer, and a cold group pulls the temperature out of your first shot.
That is why experienced users pull a blank shot to warm the group, or leave the portafilter locked in while the machine heats.
When it has become slow
Scale, almost always. Deposits on the element insulate it, so the same power takes longer to reach the same temperature. This develops over years alongside weaker steam and slower shots.
Descale.
A failing element or thermostat is possible and much rarer. If the machine never reaches temperature at all rather than taking longer, that is the direction to look.
The practical fix
A timer socket. Set it to switch on half an hour before you get up. Full thermal stability when you need it, nothing burning electricity the rest of the day.
Last reviewed 8 August 2026