ariston e combi

[buckley plumb]

had a call of customer e combi works on hw but only runs for 15 - 20 mins on htg. whats confusing is when the boiler is in htg mode the yellow light is flashing but boiler works as normal for 20 mins with this light flashing but after 20 mins all the lights go out except the green power on light and the leds that represent the temp and these eventualy phase out when the water cools. the boiler will not re fire untill its switched off and on then same occurs.looked in error codes in manual but nothing there about yellow light being on when boiler is working. any help would be appreciated

ant

 

[buckley plumb]

think i have sorted it disconnected the room stat and linked the stat terminals and seems ok now must have been rf stat shorting and interfearing with the pcb as its low voltage.time will tell