what does d mean in display? on a ferolli gas boiler?

have you checked the water pressure, it should be on 1 when the system is cold.if it,s higher you need to check your blow off is not running and check the fill loop is turned off.if the blow off is running you will need to get someone to put a new pressure relief on your boiler.if it,s under 1 top it up at the fill loop make sure you turn the fill loop back off

steve
November 2008

It means Delay. It is delaying from Hot Water mode to Heating Mode. Someone has run a tap when it is in Heating Mode and it takes 2 minutes to go back to Heating Mode again. You can turn this down to 30 secs if required.

Hope this helps.

Nick

KOPPA Plumbing & Heating
November 2008