Just simplifying storage heaters , I think yours may be the older ones that needed a boost charge during the day .
However they are not intended to be switched on & off at will like a fan heater ,say. A time switch allows power to them during the OFF PEAK period at night, the bricks inside them contain the heat and release it slowly. During the day there is no power to them (Econ 7) Your Econ 10 has a midday boost .
Like Stepps says , if you are out during the day , turn the OUTPUT down to retain heat for the evening.
Edit; Just re-read your post , they are not very flexible I'm afraid , although yours recharge in the the day , you could try opening the OUTPUT and warming room #1 while retaining it in the heater in room #2 for use later .
I may be rambling now :C