While you wait for answers, we may have found some information which could help you.
Success
Message
Trianco Optima Boiler Programmer Fault (QA73)?
Pilot light will not ignite?
how can i fix boiler?
optima 701 pressure rises when heatings on drops when off?
Optima failing to fire up?
how do i depressurise a ferrolli optima boiler?
how can i fix my ferolli optima 701?
high pressure when heatings on?
Why does the Hawk II Optima keep turning on central heating without request?
Big bang on ignition?
Why do my TRV's rattle?
OPTIMA 701 Ferrori heating problem?