chaff britony combi 80. hot water fine, heating problem comes on low rate 10 secs then off cycles again when htg on constant.no rads htg at all.pump hot but ok no air locks.suspect dhw switch stuck in dhw position or stuck diverter valve?any help appreciated.thankyou

mike bonning, November 2007

To check if its the 3 port valve (diverter) check the lever on the motorised head to see what setting its on as when calling for heat it should be either mid position or heat. To get heat on the tempory basis try moving the lever manually and if it works take off the head and fit the valve to mid position whilst you arrange a replacement.

stephen, November 2007