Have you carried out a soundness check at any point after removing the pipework...If not...you are placing your life at risk..The analogy of replacing a light bulb is v v inaccurate.I would compare it more to servicing your car brakes when you do not have a clue,then riding around with your family in it..If you have half a brain cell of course you know it's dodgy messing with gas if you are not compayent.even in your own home.And the mere fact you come on here seeking advice proves you have not a clue.I have no axe to grind.Only 30 years of experience with gas.
I have not removed any pipework. It was removed by a gas engineer.
I didn't actually use an analogy, I used an example.
The whole point of my question was to determine whether removing a disconnected fire is "messing with gas" or just removing an inert object. And it was JUST a question. I have enough of a clue to know that "messing" with gas is dangerous and how combustion works. I am curious how this would still be possible having removed fuel from the equation. Residual gas in the (leaky, vented) pipe?
Your 30 years experience does not give you the right to treat me like an idiot, but it should give you the ability to help me, and others, to better understand our queries. If you are unwilling to do that in a mature and patient manner then I do not see any point or benefit to you contributing to these fora.