Thank you guys again. You can stop now. Quick update then. The Works clerk came over this morning, looked at the boiler & flue, agreed that it shouldn't have been taped, said
look liked it was a temporary job, that never got fixed. Inside does like flue parts have been mixed together, outside is ok, will find out why it was left like that and why it was never picked up before. Reassured me that there was no CO leaking, and that if it had, my CO detector whould have picked it up. Said I'd get a like for like combi, considering me & my building got it back in early 2003's and I'd get a new bathroom radiator too, since that was rusty.
Asked how long all this would like, he said about within 10 Days, Asbestos check has to be done first, and all that.
I guess I can't & shouldn't complain.
So thank you once again. It wa good to rant. And we can close this thread.