Hello - we recently had a Worcester Bosch engineer round to fit a new PRV. He checked the working gas pressure and found the pressure to be 3.6 millibars at the gas inlet. It's 20 millibars at the meter. We've had this confirmed by another engineer.
We had an extension built 4 years ago and a new Worcester Bosch Greenstar boiler installed. The gas meter is at the front of the house which wasn't touched during the extension. I presume that from here the gas run goes under the floorboards (easily removable) and into the new extension which has a Polypipe UFH system and tiles (not very removable) and then into the boiler. Total distance is approx 8-10 meters.
Without going into great detail our builders were pretty terrible and we've had a number of issues. My guess is that during the build some debris has fallen into the newly installed gas run somewhere along the line rather than it being undersized pipes. Alternatively some corrosion has occurred in the old pipes resulting in a blockage.
Before I begin tearing up the floor to find out what's going on is there anything I could do to explore in more detail? I was thinking of some sort of camera down the gas run but I really have no idea. Someone has mentioned high pressure air through the pipes... Are either of these options viable, do plumbers do this sort of thing?
Thank you for any advice!
James