I have just moved into a flat with a bosch worcester combination boiler that was fitted in January 2006. I called out a service engineer as the pressure was dropping from 1.5 to 0 on a daily basis. I have been told that I have a leak, which is undetected as the pipework is housed under my concrete floor! I have injected a sealant into the system which has reduced the pressure loss to 1.5 - 0 over 5 days. Still not perfect. There is no sign of water damage anywhere, I obviously don't want to have to have my floors dug up! Any ideas on what I should do next would be gratefully received.
Regards
Melanie