Every winter the coil goes bad in our submerged well power box. It's been professionally replaced 3 times. The pump in new this summer. It feeds a burried tank and is gravity fed only. This time there was buzzing and when we cycled the breaker the buzzing got louder until the entire box started violently vibrating. The pump was not vibrating. The coil will only stay on if we push the switch in the middle of it. We only have one company that can look at itand they can't seem to get it fixed to last. Ideas?