ALPHA CB24 COMES ON IF IT HAS A GHOST IN IT?

ANY ONE CAN HELP US WE HAVE A ALPHA CB24 COMBI
BOILER IS OLD JUST USED IT FOR HOT WATER BUT HAVE
BEEN ADDING THE RADS IT IT. OUR PROBLEM IS WHEN WE PUT IT ON TO JUST HOT WATER IT TURNS THE HEATING ON TOO . AND WHEN TURNED OFF THE
HEATING AND HOT WATER IS STILL ON PLUS ORANGE
LIGHT FOR ABOUT TEN MINS THAN GOES BACK TO NORMAL RUNNING. AND IN THE DAY IT COMES ON .
HAS IF IT HAS A GHOST IN IT.