A pot on the oven had been left on and smoke was filling the flat.
It was taken outside and the couple woken up by firefighters.
Harewood station officer Russell Fairbrass said the couple was lucky their bedroom was closed as smoke filled the flat.
"The (smoke) alarm was audible through the door so I'm not to sure why they didn't wake up . . . they are quite lucky as these kind of fires can get pretty big, pretty fast," he said.
Mr Fairbrass said it was an all to common event they had to deal with and had one simple message.
"Keep looking while your cooking," he said.
While firefighters were clearing the house of smoke they installed another smoke alarm in the bedroom.