Confused?

what would cause radiators to be hot when heating had been off for 2hrs?
One in shower room and the other in bathroom quite hot.
Airing cupboard in shower room housing hot water cylinder and c/heating pump.
There are what appears to be two motorised valves in the pipework next to the h/w cylinder.

Confused considering the boiler was off and this was 12.45pm and boiler not due on until 4.30pm (16.30hrs)



Thanks in anticipation.