Thanks for the advice. I found that the ceramic fibre board is expensive to order since it is fragile and typically has to be delivered by pallet or by courier. I found it cheaper to order some ceramic fibre blanket from Vitcas
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). The blanket can be fixed to the steel panel/cover with a ceramic fibre adhesive
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). Its also possible to protect the blanket using a heat-resistant cloth
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). These products are rated to temperatures above 1000 degrees C, which I've read is far higher than the temperatures likely to be encountered in a storage heater. For instance, my Dimplex heater elements can only reach 650 degrees C. Obviously, heater temperatures should be far lower than this under normal operation.