While you wait for answers, we may have found some information which could help you.
Click here for Combination Boiler Heatingpressure relief valve?
My heating and hot water do not work and “A03” is flashing?
My boiler won't light but will when we take the cover off ?
Relight pilot?
chaffoteaux brittony combi se 80?
gas water heater chaffoteaux britony 11t (geyser ) 11 years old?