While you wait for answers, we may have found some information which could help you.
Click here for Combi Pipe Pressure Timechaffoteaux calydra 80 combi boiler?
pressure relief valve?
My heating and hot water do not work and “A03” is flashing?
Chaffoteaux et Maury with no hot water?
How can I fix my Chaffoteaux & Maury boiler?
My boiler won't light but will when we take the cover off ?