vokera runs hot then cold?

Venturi possibly dirty or blocked, but could do with knowing which model, also domestic heat exchanger may be blocked due to dirty system water. If boiler is a standard linea, turn cold water inlet valve of when burner shuts of you should see the primary ntc sensor race upto 90 degrees plus. This will tell of a blocked exchanger.

Big A
December 2007

mines the same,i need help 2

dexter
December 2007

Google 'vokera flue venturi' or search this site.

c
December 2007