Autosleeper 2008 Nuevo.

Hi everyone and thanks for letting me join.
We have the Trumatic s3002 space Heater fitted inside the wardrobe under an hatch which works fine. We have a problem at the moment with the heater insulation, it encases the back of the fire and flew system, this is now just one big lump of material that doesn't cover the fire anymore.......I'm guessing it limits the amount of heat entering the wardrobe Space. 
So basically I'm looking for a replacement product or even the correct part, could anyone point me in the right direction.
TIA