Hmmm, Surely this is a nice black and white isn't it. If you cut the gas line, move, disturb or replace the flue then an RGI is required. Yes this is a DIY forum, but i for one won't help someone break the law. Yes....the law. I don't like cameras waiting to catch me doing 34 in a 30 but....thats the law.
Surely, refitting would require benchmarking again (how you gunna know it's burning correctly?)......does the op know how to do this, and all the other things mentioned. Get a RGI to do the job (or at least the safety/law critical stuff)
Surely, refitting would require benchmarking again (how you gunna know it's burning correctly?)......does the op know how to do this, and all the other things mentioned. Get a RGI to do the job (or at least the safety/law critical stuff)