cant turn off heating

[alexbetts]

hi, the heating pump wont turn off even when the timer is in the off position, the room stat is on 0 and the thermostat on the BB is in the 0 position the flame goes down to just the pilot but pump continues to send hot water round the system

any help would be appreciated

 

[dcawkwell]

Faulty electrical 2 port or 3 port valve.
If you have a 2 port or 3 port valve try giving it a sharp tap.
Or faulty in boiler on pump overrun.