oil combi boiler -water timer

jillybee

I have a new condensing combi boiler (oil), it has a internal hot water storage tank.
Will it be more money saving to leave the hot water timer on all the time or set the timer for the morning shower and evening dishes etc? (does it use more oil to heat up cold water than to keep hot water hot? - i dont know..)
Also how long before I require hot water should I turn the timer on?

Thanks for any help.

ariba10

It costs more to keep the water hot all the time.