Hi.   pressure keeps dropping on gauge with external pipe dripping

Baz, April 2012

Could be faulty pressure relief valve? could be expansion vessel needs recharging (pumping up) To do this you need a pump with an accurate pressure gauge, and there needs to be no pressure in the heating system when it's recharged. Normally around .7 to 1.0 bar?, but you would have to check the manufactures spec.

ajax, April 2012

Change pressure relief valve

ltd, April 2012