how do i set the heater to have hot water whilst the heating is off?

Most modern heating systems are controlled by a timer or programmer. They have two channels, one for hot water and one for heating. Each channel can be set independently from one another in any combination of:

OFF - ON once per day - ON twice per day - ON constantly

Many have the ability to have different ON/OFF times for weekdays and weekends.

A few systems have the timer/programmer built into the boiler enclosure as a user control. For nearly all types you have to open a flap to access the setting panel.

Find your programmer and adjust it. If you don't have one it will be a very unusual installation.

Peccavi
December 2008