The pressure in my system has dropped to 0.5 bar so I have an error message 21 and no hot water or heating.

The boiler manual says to gently open the blue filling tap to re-pressurise but when i do this i cant hear any water entering the boiler and water starts to drip out from the drain cock.

Help!!

Simon Gardner, February 2010

turn the blue filling cock open and switch the boiler off then on at the power socket, repeat switching on and off till pressure is back up to 1.5 bar........the water dripping will stop when cock is closed again

GMB, March 2010

you need a new filling cock, they are well known for being faulty. either that or have an external filling loop fitted.

Ian, February 2010