potterton kingfisher mf rs 80 user controls not responding?

The HW light stays lit and the clock shows 6:00 pm no matte what is done to the controls. This is also the state after a power off and back on. The sliders do nothing either. Turning the temp control on causes constant hot water. The flame light comes on and for about 5mins and then goes out. It seems like the timer is stuck on... Any pointers?