Thanks in advance. I have a gas hot water heater question.
Our 75-gallon hot water heater is located in the basement. We have a recirculating pump on the heater that supplies instant hot water, (about 5-10 seconds), to the upstairs, (2 floors above the basement). I decided to see how long it takes for hot water to reach the upstairs shower when the pump is unplugged. I was surprised to find that the shower gets hot water in a similar amount of time, (about 7-10 seconds).
Please see my photo below, (hope the pic worked). My question is this: Is the hot water, that is coming up to the shower, flowing through the same pipe that the hot water pump is sitting on? Meaning, I know that when the pump is running it forces the water through the pipe that pump is connected to. So, when the pump is disconnected and I get fast hot water in the shower, is that water running through the same pipe? If yes, then great. If no, should I have concerns that the water in that pipe will get stagnant?
I hope my question makes sense to those with a plumbing background.
Thank,
Larry


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Yes especially if the check valve is bad it certainly could back feed I’ve seen plenty of houses piped with a recirculating line and no pump however I cannot say some water won’t possibly get stagnant

Thanks Bsipps.

I not sure I understand what you are saying. Are you saying that when I do not have the pump plugged in, the water going upstairs does not run through the pipe that the pump is mounted on?

My plan, and please tell me if you think it's smart, is to plug in the pump once a month when I take a shower and then unplug it.

Thanks,
Larry

Your recirculating line could “self flush” while any faucet is in use meaning fresh water should flow through it even with the pump not functioning but there’s no guarantee

I think my plan of running the pump for one shower a month makes the most sense.
I appreciate the time you took to help me out.
Larry

How long after you unplugged the pump did you test for hot water? A little confused here.