i've got a baxi combi 105e which until yesterday worked fine. there have been a few bangs from the heating over the last couple of days. i bled the radiators. when i looked at the boiler the triangular icon was flashing. after looking this up in the manual it looks like the system needs re-pressurising...the pressure gauge? shows 0.. is there something i can do to fix this or do i need to get someone out...thanks