Saltfire Peanut 5 - 5kw Defra Wood Burning Stove. ThisSaltfire Peanut 5 is an DEFRA Approved Wood Burning Stove. ThePeanut 5 is a compact 5kW stove featuring all-cast-iron construction for maximum heat-retention and ultra-clean-burning, by keeping the belly of the fire hot even during ‘low & slow’ burning.