Newbie heating problem

[Chris Bithell]

Hi. Thank you for the quick ad...
Can you help? I have a oil fired firebird 90 with rielo burner...and Drayton control.
The heating stopped working this afternoon . I pressed the boost on the hot water side and it kicked in..I thought it could have been the control unit so I replaced it with an old one that I knew worked...still the same.
So,as it is now, the heating side is working but only when the hot water is switched on...Any ideas? Dumb down any responses please I'm a car mechanic by trade..Chris

 

[SimonG]

Motorised valve

 

[Chris Bithell]

Motorised valve

Thank you. .. you are a star...