Low pressure

[flotmangooner]

Hi
My Vaillant ecotec plus system boiler didn't fire up early this morning because the water pressure was too low. This seems to be happening more and more and each time i have to re-fill the boiler via the two black taps on the pipes underneath the boiler.
I have noticed in my airing cupboard that the copper pipe coming from the bottom of the hot water cylinder is quite messy with green sort of 'fur' and if i put my fingers on it they get wet so it looks like water is dripping out somewhere - is this likely to be the cause why the pressure is dropping on a regular basis ?
Thanks

 

[Madrab]

Sounds like you might have a leak in the heating circuit pipework/radiators somewhere or a faulty pressure relief valve but I'd put my money on the former. Are you getting cloudy hot water or an overflow constantly running problem? Just to rule out the coil in the HW cylinder

The lowest pipe on the hw cylinder is usually the cold inlet pipe from the cold water tank and you may have a weeping joint but wouldn't be why your losing pressure on the heating.