While you wait for answers, we may have found some information which could help you.
Click here for Combi Water PressureRemeha Avanta Plus not not activating heating?
How can I fix my Remeha Avanta Plus boiler?
Remeha Avanta plus?
pressure gauge fault?
Remeha avanta boiler 28 - help???
Remeha Avanta Plus 28c no hot water but still have heating?