Heatline Star 24

[h17sym]

Hi, I have looked at a customers Heatline today, the overheat stat light was flashing constantley so repaced that with a new one, the boiler then worked fine for about 10-15 seconds before cutting out again and cluttering noise near the pump, heatline technical advised that there could be an external blockage and recomenned to flush the system and also replace the pump. any ideas which to look at first.
thanks

 

[Kip]

Is the pump actually pumping? Could be that it thinks it is but isnt.

Or a blockage of air of ****e out in the system.

 

[h17sym]

hi kip the pump was pumping for about 10 sec's before making the cluttering sound..

 

[REDSAW]

chchchch changes the pump bearings knacked