Help with Britony SE80

[shocking]

After using the shower water turned off, I find the boiler still operating with no flame. The fault leds show 60 70 flashing. The fault finding page in the manual, states Anti frost mode on (burner and pump in operation), but there is no flame’ and sometimes during the day the boiler starts up.

2009. I changed the diverter valve and both thermistors.
2010 I changed P C B ionization board.
After I installing P C B I noticed that the led lights in DHW mode Continuously rotate in pairs left to right across the panel, when I enquired to the supplier, they said that the new ones do this

Any Ideas please.

 

[picasso]

The new pcb may have pump over run on hot water, when the boiler starts up during the day does the flame come on ?

 

[shocking]

Yes it always starts normaly