Just back off hols in Lanzarote, all lovely. Arrived home very weary at 3 AM and as approaching the house thought " The wheely bin don't half pong a bit" as I opened the front door and instinctively went for the light switch the realisation hit me that the house was actually completely rammed with gas, turns out Father in law ( stone deaf ) had kindly brought some milk etc that morning and had inadvertently knocked one of the gas rings on and this had been hissing away in the sealed up house for nigh on 15 hrs
Stupidly went in and opened every door and window, Christ it was potent, BG emergency where round in half an hour or so and after a while the sniffer said it had dissipated enough to go in.
I'll remember to turn off the mains next time, something I've never considered doing before. Won't tell FIL as he'd be distraught
Free carbon monoxide detector was a bonus