All too true, that's the spot to clean, seems it needs to complete a circuit ... I played with a magnet and no mouth piece it stays on in temp change mode. I then put magnet near top of lights and it goes off... Shut down like mp is retracted.. See magnet in mp, silver rectangle.. I thus see no magnet near the lights turns on but without mp its temp mode. I left mp out and joined inner tube to outer(spring) puts on heat mode, purple lights. So that's why pushing mp to edge works... It completes electric circuit that enables heater core. That's the spot or cleaning g-spot or our beloved pax..