Having bled my radiators yesterday morning, I returned home to find my heating not working. Hot water was on but cold radiators. I realised the pressure was too low on the boiler (0.5 bar) so followed previous instructions to raise it. Unfortunately it went too high -up to 2 bars and the manual says 1.5 bars max. I can't locate the pressure release tap - Should I worry or will it be ok? Someone mentioned it may damage the diaphram??