Deirdre I can't help with the heater guard sorry. With regards to the gate though if you look at them at the shops it says on the box how wide you can extend a "normal" gate to using extensions. I don't have the box anymore so can't have a look. I do have a feeling though that you will have to buy an actual wider one. Have a little look on ebay as I've seen some really big ones there which I believe you can adjust to all different sizes. HTH.