Seeking a little advice. 24kWh Storage heater Dedicated feed from CU. 40A MCB >>>> 40A DP switch >>>> timer box >>>>> 24kWh heater.........all 2.5mm cable. Live has melted brown covering and DP box - this is the feed from DP box to timer. No smell or damage at timer, heater checked and all OK, no smell or heated cable anywher else on circuit. Is the MCB too large B40A ?? If heat had travelled up from heater - then I would expect smell/damage at timer, but nothing there, melt point is at DP box live to the timer. Any advice would be appreciated.