My house currently has a hot water recirculation system, but it does not seem to be functioning as the water in the upper levels take minutes to get warm.
First off, I tried to determine whether I had a dedicated return line for recirculation. The piping around the water heater was quite complicated and I could not figure out what goes where, so instead I opted to look under the all the sinks in the house to determine if there was a temperature valve. Having seen none, I deduced that we had a dedicated recirculation line.
At this point I'm not sure how to proceed. The pump appears to be working. When plugged in, it hums along and I can feel the flow of water along the lines. Unfortunately, the water heater does not turn on at all when the pump is on, and there is no noticeable difference in the time it takes for hot water to reach the sinks in the furthest fixtures.
I've attached pictures of the piping around the water heater + pump for clarity.
Edit: I've removed the insulation on the pipes in the pictures for more clarity