As above a 1 meter section of plastic pipe joins onto the lead watermain under the floor,whilst the gas supply

pipe passes through a brick wall and awaits the gas meter to be fitted.My thoughts are that the gas pipe through

the wall is giving the low reading,but could the water in the plastic also be contributing since it connects to the lead?

Gas and water pipes are glanded into the boiler,which is not electrically connected atm.I have main bonded gas

and water,although in theory the water does not need bonding.Thanks for any advice.

                                                                                                    Regards,

                                                                                                           Hz