I have the P1353ME Intermatic Timer that controls the time for our Polaris 280 pool sweep and the pool lights. This morning it "clicked" on to turn on the Polaris pool sweep and started making a loud humming noise, the sweep did not turn on (circut 1 button). The light control (circut 2 button) works. circut 3 button, not in use. Any idea what this means? Thank you.