problem with heating controls?
 
                potterton netaheat 16/22 with potterton 3 port valve TYPE MSV 322. when turning heating off ,but leaving H.W on i find that rads are still hot is it likely to be valve body, or actuator unit, or is whole assembly one unit. any info; on replacement part ref; no,and approx cost?
            
             dave p.
            
 April 2009