I have an unvented Vaillant condensing boiler which is regularly losing pressure - I guestimate te loss to be of the order of about 3 pints per week judging by the length of time I have to open the valve on the filling loop. (The gauge on the boiler falls to zero and said boiler starts to make strangulated noises...)
This has been happening all summer, ie with the CH switched off. I can't see any leaks anywhere, and the tundish by the pressure relief valve is dry; but logic tells me the water must be going somewhere, and surely at this rate ought to be detectable. Where's it going?!
Thanks David