System functions OK, both heating and water, while the timer/controller is on. However when the timer is on off, heating stops but water continues to be on> This is noticeable by the fact that the boiler continues to fire up every now and then. The only way this can be stopped is by turning off all electricity power to the controller which means I have to reset the programmer every time I wish to fire up the boiler> Another thing which may or not be related, the theromostat has no control over the temperature
The one component that over rides the programmer is the frost thermostat. Worth having it checked and how it is wired into the control. Failing this the boiler electrical controls should be checked. What type of boiler is it?