While you wait for answers, we may have found some information which could help you.
Click here for Heating Temperature Fault
Volkera minute e20 will not ignite?
volkera linea 28 no hot water?
my volkera linea 24 boiler keeps losing pressure?
Volkera SP80?
Volkera compact 29A Combi always making kettling noise?
How to re pressurise a volkera boiler ?