vokera mynute12e runs when programmer off?

boiler runs when c.h. and h.w. times have switched off.
checked out m/valve-switch is open. it has a 2-channel internal clock which i thought might be faulty.
The clock is now obselete. i fitted an external programmer and altered wiring centre. fault ongoing.
The boiler can run ok for a few days then keep running after off times