Boilermate 2000 - Central heating running when manual override set to off

I have a Boilermate 2000 (No Switch) and have an issue whereby the central heating will run even when the manual override switch on the timer is set to permanently off. The timer seems to be ignored completely and so when it is set be timer operated the central heating does not switch off during the required periods. The central heating can be stopped by suitably lowering the room thermostat and the hot water is just fine. Is this likely to be a faulty timer or controller board?

Hi, sorry to hijack your thread. I just moved into a 2005 build house with this system. I have exactly the same problem. The heating is always on, the timer has no effect. I can turn it off by lowering the thermostat.

I am thinking of replacing the analogue timer for a digital one, or replacing the hallway thermostat for a digital timed one.

Sorry I was somewhat rude and didn't even offer a please or thank you. Any help with this issue would be greatly appreciated. Thanks in advance.