Dave,
You're probably right about the timer costing less. But the sensor
couldn't be a flow switch as it was installed at the furthest point from
the water heater and the spigots closer to the heater couldn't trigger
it. I'm pretty sure it has to be a pressure sensor that could detect a
momentary drop in pressure. I do remember that it only took a
momentary on-off of any hot spigot to trigger the pump to turn on.
Art

"Dave, I can't do that" wrote ...
On Oct 8, 1:44 pm, "Artemus" wrote:

Hi Art,

from the water heater. When a sensor detected a drop in the hot
line pressure the pump would turn on and pump from the hot line

Hmmm, seems a better system than the current one with timer a timer. I
guess a timer costs less than a flow switch. g

Dave