Marcus: What component would most likely cause my 40amp breaker to trip? My Jandy model# AE2000T Pool Heat Pump serial# L07AD0453 was installed in 2007. For four seasons it heated our pool wonderfully. I opened the pool this season and started the heat pump. It ran for a half day when I determined the pool temperature was not rising. I turned it off. The next day I started it again, but after about 5-10 seconds the 40amp breaker tripped. The fan was beginning to spin freely. Pool water flow is fine. I had an electrician check the breakers both at the unit and in the circuit panel and they are in working order. The unit is recording about 150amps under start-up load, prior to tripping. Because the power shuts-off when the breaker trips, our service tech is unable to receive any codes at the control panel. I have not found any troubleshooting tips for this problem. I am hoping you have experience with this issue? Thanks, Kevin.