Hi i had a gas open fire fitted about a year ago by a corgi reg fitter and this winter have started to notice it very cold around the fireplace when the fire is off. like there is a draft blowing into the living room. I also get a draft from under the living room door when sat on the floor. I know that this is chimney draw. But would one of those anti draft cowls help much as i only have a cage fitted???. And should i notice a draft under the door that much??? Thanks