How do I know what fire will fit if i want to replace my old gas fire in the living room

You need to get a registered HETAS installer around to do the calculations for you and do a site survey firstly.

Hi Geoff if your fire is the Valor Visage then its a standard 16 x 22 inset gas fire. You will need to check the flue type as a proper chimney is a class 1 and a flue which terminates on the roof top is a cat 2. Both fires have different depths and flues sizes with cat 1 being the largest which will enable you to pretty much install anything you like. Try and find a local specialist as most of us offer a free visit to advise and ensure you get the right product. Ensure the engineer is on the gas safe register and that on the rear of his licence he with qualified for fires