Hi, the hot water is staying on after the timer goes off! It looks as if the motorised valve is staying on. Do I need to replace the valve?

Could you tell us a bit more, what fixture is this timer on?

The timer is a Honeywell timer & controls the Heating & Water.
What happens is after the timer goes off, you can still hear the boiler firing up.
I have been able to manually switch the (Danfoss) motorised valve off.
This seems to be an intermittent problem.
Cheers.

Are we talking about a water heater or a hot water heating system? Cheers, Tom

This is part of the heating system. I have a combi boiler with a hot water tank. The heating side of things is fine. Cheers