While you wait for answers, we may have found some information which could help you.
Click here for Boiler Trip Switchwhy does pressure keep rising when heating on?
Alpha CB24/28?
how can I fix a leaking drain pit cock?
Alpha CB24 no hot water?
alpha cb24 red and yellow alternate flashing?
pressure on guage is 4 bar what can i do to solve it its a alpha HE cb 25 b?