I let the central heating pressure on my Gloworm Swiftflo combi drop to the point where the red flashing warning light came on. The boiler was switched off at the mains by someone who thought it was dangerous. Next day I turned the valve to fill the CH pressure up to just above one bar then switched the power back on. The boiler made grumbling noises (which it might have been making before - not sure about that) then there was a pop and the lights on the boiler went out. Now water is leaking from a pressure release valve inside the boiler.
My question is what what happened and what do I do to fix this?
Please don't say call a Corgi registered engineer, I'm not about to go sawing through any gas pipes.
Thanks for any advice.
Brendan.