My dd had slept through from about 3 months, then at 6 or so months started waking in the night, once, but being very difficult to soothe. After about a month I finally realised that each time I woke to her crying, the heating was on. I tested the next day and discovered that when the heating turns on, it is VERY loud as it is just underneath her bedroom. It makes quite a loud bang, and it must have been scaring her from her sleep. Anyway, we now don't have the heating on until we wake up. It's very cold in the morning but we're sleeping through again.
Just thought I'd post in case anyone else was in a similar situation. Maybe you're all a bit cleverer than me though!
