A chemistry academic and his family lived to tell the tale of how carbon monoxide gas filled their Leicester home, but it was not their CO alarm but the alarm clock that saved them.

Carl Schieferstein was awoken by his alarm clock at 7am on the morning of September 10 but he was so groggy and disorientated by inhaling carbon monoxide fumes, he nearly fell over when he tried getting out of bed.

His wife found the simple action of switching off the alarm clock a tough task because her drowsy state made reaching the clock a struggle.

Schieferstein believes he and his family would have been dead if his alarm clock hadn't sounded because their carbon monoxide alarm failed to alert them.

"The carbon monoxide alarm didn't go off until I took it off the wall", said Carl Schieferstein.

Getting the couple's two children , aged 6 and 9, up and out of the house also proved a challenge. Summing up their symptoms, he said "We felt sick and had headaches. My headache lasted all day".

Referring to the silent carbon monoxide alarm, he said "I checked the batteries and there was enough power in them.

"I'd like to complain to the manufacturer of the alarm but I can't prove or disprove how much carbon dioxide was in the house.

"We definitely suffered from the effects of the fumes. I'm sure that it would not have been long before the gas had got us for good".

Schieferstein said his children were playing football outside the house the night before and says they accidentally disturbed a plank of wood which blocked a heating vent.