I’m pregnant and we have had an ongoing really really strange egg smell from the boiler for the last 4 months. We’ve had British Gas in and been told that there’s no gas leak but probably bacteria in the boiler piping and the same comment from a gas engineer we had sent out. We have carbon monoxide alarms and none have gone off but I’ve recently read about propane and/or hydrogen sulfide which can give off this smell. And if it is bacteria or propane then both could give off hydrogen sulfide. We can’t afford to replace it for another month. We don’t smell it all day everyday but it’s there and close to where we sleep (boiler room next door). I’m panicking a lot and have called the midwife and she just said there’s no Carbon mo oxide in my breath tests but it’s not that I’m worried about!