My heating comes on even though its all turned off!!!?

I have a Potterton EP2000 boiler and the heating is coming on when the hot water kicks in! However, there is an antiseptic smell coming from the airing cupboard that has only started this weekend since the heating has been playing up. I am going to contact a pro tomorrow as I wouldn't dream of touching it myself, but I'm just looking for some reassurance that it's safe!