Hi, I have an annoying problem with a Baxi 80 eco. I am losing pressure over a few days, I have checked the system for leaks and found a few (some quite bad) and fixed these but it seems to have made the pressure drop even quicker. Have also replaced the pressure relief valve and some o rings that seal the pump but still losing pressure. Another problem that has developed is a groaning/whistling noise when the pressure gets to 1 bar which is cured by filling the system up to 2 bar. I have bought some fernox leak sealer but I am reluctant to put it in as the problem must be quite major for the pressure to drop so quickly. The boiler is in the loft so it is a pain to keep filling. Any advise would be greatly appreciated.