my heating will only come on when the system is heating the hot water. can you let me know what I should look for. The Pump is a Myson with a Honeywell F5 9525 switch box. I have noticed that the switch will not stay in the on position if I move it manually. It is a baxi back boiler with a Drayton Switchmaster SM 905. thank you for any help

legh-smith, January 2009