Clearance Wooden Swing Sets What Is The Minimum Clearance Allowed Bewtween A Free Standing Gas Stove/fireplace And A Wooden Lintel?

What is the minimum clearance allowed bewtween a free standing gas stove/fireplace and a wooden lintel? - clearance wooden swing sets

I have a 700mm high free gas stove / fireplace, over which I put a wooden lintel. What is the minimum distance between the stove and allowed to fall?