New house has traditional boiler - hot water is rubbish

[fruitstick]

Help. I've only ever had a combi boiler before. Our new house has traditional boiler with hot water tank.

But the pressure seems to be rubbish. Take 20 mins to
Run Dc bath. Same with shower - trickle.

My questions

Am I doing something wrong?
How long should you set timer for hot water everyday to make sure you have enough.

Might have to sell up if I'm destined for rubbish showers forever!