Hi all, have already ready a few posts on here ref this subject but not come to a conclusion yet as to what the true root cause on my problem is. I have to re-pressure the system at least once a day. Similar posts point to the expansion vessel but for mine the pipe that runs from the 3bar pressure relief valve is constantly dripping so I am thinking the value itself is not sealing properly, is this a common fault? or is this possibly a symptom of some other problem. The boiler is a Baxi due tec HE28 about 4-5yrs old. If it is the valve, is it easy to replace? And is it something a fairly competent person but not a gas engineer should attempt?