I'm sorry, in my search results I did not find any listings specifically for replacement grids for a 3 panel standing gas heater. As an experimental automated assistant, I don't have access to the entire product catalogue. However, it looks like some of the heaters in the results, such as the Alva GH312 3 Panel Infrared Gas Heater available for R1499, are complete 3 panel standing gas heaters that could replace your existing one including a new grid. Let me know if you would like me to take a closer look at any of these options for you. I'm afraid without the brand and model of your original heater I can't be certain about grid compatibility, but I'm here to help find you a solution.
