Troubleshooting A Chattering Hot Tub Contactor

A chattering contactor is a contactor that is switching on and off continuously. The switching on and off causes a clicking sound and this is where the "chattering contactor" term came from. If you have a chattering contactor, these steps may help you find the problem:

1. Test the voltage at the coil. If you have proper voltage, continue to step 2. If you don't have proper voltage at the coil, proceed to step 5.
2. Test the pressure switch and adjust if it is too sensitive or replace if it is faulty. Proceed to step 3 if this isn't the problem.
3. Test the thermostat to check if it is releasing properly when the spa reaches the set temperature. If it is "hanging on", replace the thermostat. Proceed to step 4 if this isn't the problem.
4. Check all other components on the coil side and look for any loose connections. If all of the components and connections are fine, then the contactor is causing the problem and needs to be replaced.
5. If your voltage test in step 1 determined low voltage, test the main panel for voltage. If there is low voltage at the panel, call your electrical utility provider to look at the problem.
6. If the voltage is fine on the main panel, test for low voltage at the spa pack. If there is low voltage, check for feed wire being too small or for burn marks on the wire. If the voltage is fine at the spa pack, test for voltage through the coil circuit to determine the fault.