When switching to dhw, the boiler runs for a few seconds, switches off the flame waits then restarts again, cycling again. The green led flashes [normal] throughout. dhw temp runs at 56/58c. using the shower is the worst culprit. have changed the mixer, makes no difference.
Any suggestions?
regards

David O., December 2007

try cleaning the venturi, and maybe replace dhw ntc also set gas pressures hi and low

Big A, December 2007