My Enviro Vista Flame VF100 will need some insulation cloth that goes behind the center firebox panel. The piece that's in there is 8 years old and is falling apart. I had an oil service tech here today putting a part in my FHA furnace and he said that the cloth is VERY expensive. I know that the Enviro OEM replacement part is over $200. The tech told me about some material called "Zero Board" that is pretty cheap. It comes in 1", 3/4", and 1/2" thickness. The tech also told me that the stuff will withstand over 1500 . Does any one know if the Zero Board will be an acceptable replacement for the original cloth?