While you wait for answers, we may have found some information which could help you.
Click here for Switched Water FinePotterton Prima 30F?
Potterton Prima 60F- can you start it manually?
Pressure gauge on a Potterton Boiler?
My potterton boiler keeps losing water pressure and condens?
Potterton heatmax combi?
How to replace Potterton EP 3002 with EP 2?