boiler/hot water tank issue

[WoodWorm99]

Hi

We've recently moved into an old property, which has a separate hot water cylinder and boiler. We've recently been programming heating to come on at around 6am, which is also when our hot water starts to heat up for a shower at 7am. However, since programming this we've noticed that the hot water doesn't last as long as it used to for 2 showers. Excuse the ignorance, but aren't these two separate things, and shouldn't really affect one another?

Any help would be grateful

Thanks

 

[kevplumb]

depends on the system

try setting the water an hour earlier