The heavy weight probably caused the drum to collide with the circuit board. This has possibly damaged the relay switch that controls the heater, preventing it from switching the heater on. First check the 2 springs (above drum) and the 2 shock absorbers (below drum) are still connected and working correctly. Next, check the circuit board for damage and replace any components if required. If the casing of a relay switch is damaged, you might get away with removing the damaged casing.
Ross, December 2014