My performa loses pressure over 2-3 days, its 18 months old. I have looked all over the system and cant find a leak. What could it be in the boiler???

My performa, December 2007

You will probably find the expansion vessel needs to be repressurised with air (approx 1 bar). Also check your pressure relief pipe outside (not flue) for any signs of water leaking. If water is escaping through this pipe, you will need a new pressure relief valve

Ryan, December 2007