I had the same problem with my 105e, and had a new boiler fitted last week. Your 105e needs a major repair, as the boiler has to be removed from the wall. I was quoted £300. If the boiler is over 8 years old consider a new one, about £1000. If you are over 60 you can get a government voucher (via Warm Front) tel
08003162805 for a £300 voucher. A temporary fix for the rising pressure is to drain some water from the central heating system. this will lower the pressure, but will not stop the overflow leaking. If there is room next to the boiler, an external part can be fitted to fix the problem.
John Wharrier., October 2010
