Today I noticed that both pumps (main and booster) stopped working. I checked the breaker and I also checked the power to each pump (at the output terminals of the timer) using a multi-meter. Both have power. When I flip the timer to the "on" position I detect a very slight thump sound (not a hum).
I can see that a pump may fail but both at the same time? What is going on here?
Main is pentair wisperflow 2 hp and booster is 3/4 hp challenger. I rebuilt the booster recently (3 weeks ago) but other than that nothing out of norm has taken place.