Could be one or a combination of things. You've recently cleaned the chimney and had it 10 years so that should eliminate the simple stuff - damper closed or chimney obstruction. Is your stove pipe surrounded by a brick chimney? May be a cold air inversion that'll correct itself as the flue warms. Is it a really windy day? That can affect the draw. Might have to get up on the roof and see if it's become clogged since it was cleaned. Do you have a screened chimney cap at the top?

This post was edited by jrb451 on Tue, Dec 2, 14 at 18:00