vaillant vcw 242 eh?

After DHW pipe is closed boiler start sparking again (with no fan start).After safety time boiler goes into block mode. Diverter valve is in correct position, microswitches works fine. This problem appears more and more frequently. When boiler faulty sparking usualy helps gently tapping on electronics or on boiler left side. This is the way how to prevent boiler fault.

Damjan
December 2012