Just joined site in hope of finding other sufferers. Received Warm Front Grant and installation of combi boiler and 2 radiators carried out in April. Ongoing problems since then with daily pressure drop on boiler. Engineers have been out 5 times and now say fault can only be down to leakage under concrete floor and only means of repair will be to have pipework re-routed at my cost. Ive had a combui boiler for years and never had this problem. Am now left with a system that will not operate without daily pressure increase and worry of finding funds to have pipe work sorted. Can any one offer any advice please? I'm in a worse situation than I was before I got the grant. Devastated to see that they now appearto be advising not to fit combis on old systems , this was never mentioned to me!