I have Rheem water heater and newly installed circulation pump. I am facing a weird situation with the circulation pump which is that the circulation pump is set to run between(4PM-9PM). When I take shower in the bathroom upstairs, at 10 PM. the water is barely lukewarm. However, when I take shower when pump is on, the water is hot.
I do expect the water to be hot enough after the circulation pump is off. This is because I expect that water has been heating up for 5 hours, there may be some cold water in pipes but once that water runs out, I should be receiving the hot water from the heater directly. I was in the shower for 20 minutes and I received lukewarm water for all 20 minutes.
Am I having the wrong expectation here?