just to clarify my stand on this, I quoted the law, not necerssarily what I do, but there are companies out there who comply with the law, albeit a mimimum it is their choice/contract agreement with client and not our decision, if they go above the law and find problems the client might not pay to have the work rectified so that leaves the super duper gas engineer with a problem of having isolated a gas supply that he shouldn'r have touched, as an example and sure to cause more outrage!! you do a TT on existing install, U6 meter, no smell or report of gas leak, you find 2mb drop, of those who have commented on poor standards of others, do you disconnect all appliances and prove the drop is on the carcass then have to repair or isolate, costing the customer money and inconvenience or do you comply with the law and leave the appliances on, my interpretation of allowable drop rate on existing install with existing appliances is that i can report as i find, i ALWAYS leave the appliances connected, report the 2mb drop on my paperwork, then advise the landlord/owner that further investigation could be costly and let them make the decision, also on some CP1/12 type forms it only asks for tightness test PASS/FAIL, not that any drop is recorded, I ALWAYS record any drop found so that the landlord/owner gets to decide what further action if any is carried out, a lot of people would find the 2mb drop and simply put PASS
yes you are wrong, read IGEUP1/B or tightness test procedure in your training book, there are set criteria where a TT must be done, but not every time you work on gas, but as is beoing discussed here it can be seen as best practice
the regs state we should test back to the nearest valve, when working on a gas fire as an example is is acceptable to disconnect the fire at the pedestal, remove the fire, refit and spray broken joints back to the pedestal with LDF, this fully complies with all relevant gas regs