I have a number of these type tap sets installed for > 10 years, no problems with dripping/leaking, mains pressure is 3.2/3.7bar, my daughter who lives ~ 3 miles away, same water source, (urban) has two of these type installed, one, a toilet hand basin, gravity fed, no problems after ~ 8 years, the other has one (hot) gravity tap, the other, cold, is mains fed at 4.2/4.8bar, this tap starts dripping after ~ 2.5/3 years and I have to renew the cartridge, fortunately I can source them that the handle fits as well. Is this normal?, the only difference is that the mains pressure is ~ on average 1bar higher, the water quality is excellent, when I remove the cartridge, the disc faces look perfectly clean/smooth.