While you wait for answers, we may have found some information which could help you.
Click here for Boiler Working StoppedRelight pilot?
My heating and hot water do not work and “A03” is flashing?
How can I fix my chaffoteaux & Maury Britony Combi SE?
chaffoteaux calydra 80 combi boiler?
pressure relief valve?
gas water heater chaffoteaux britony 11t (geyser ) 11 years old?