vokera problem

[bazza]

hi guys my mums boiler has developed a problem again ah ah its a vokera compact 28 the boiler works fine in hot water mode n ch mode seperately but wen the ch. heating is on and i run the shower the hot water runs cold n the burner keeps cyclin on and off main burner fires up 4 a few seconds and then knocks off i was thinkin maybe somethin 2 do with diverter valve but not sure cheers guys

[htg engineer]

The last time you had problems with this boiler - did you replace the DHW sensor ?

IF the sensor is faulty it may be retaining the heat and keep cutting the burner off (as it should) when the boiler is at the set tempererature.

To check the diverter, run the hot tap when the heating side is cold. Feel the flow and return pipes they should remain cold. The DHW draw off should be hot. I don't think it will be the diverter at fault, as this would mean the heat rather than going to the water - would be going to the radiators, so the burner would remain on as the heat can be lost via the radiators.


Hope this Helps
Htg

[bazza]

thanx htg engineer replaced dhw sensor n it worked a charm great stuff thanx 4 help bazza cheers