Swrobel
New Member
We recently purchased a 3-story duplex, and each unit had its own tank water heater, leading us to believe that the plumbing was separate for each unit. The heater on the 3rd floor of the upper unit (ours) was due for replacement, so we had our plumber replace it with a tankless Navien NPE-210A2. Times to get hot water to some of the taps in our unit were unacceptably high (>1minute), and there's no return line, so our plumber suggested installing a NaviCirc under the farthest faucet in our unit, but that didn't improve the situation at all, even at that faucet. He did some troubleshooting and eventually tried turning off the Navien and lo and behold, we still had hot water in our taps, which he said indicated a crossover with the plumbing of the lower unit that allows its tank water heater for the lower (rental) unit in the garage to provide our unit hot water. He didn't seem to have a straightforward solution to this problem and said he needed time to think it over.
Does anyone have any ideas here about what the most straightforward solution to this problem is? We don't need instant hot water, but would certainly like to get it more quickly than we are currently.
As an aside, I suppose it's possible that the NaviCirc we received was bad, and I could get another one and try it out. Is it at all possible that the Navien + NaviCirc would work in this configuration, with the other hot water heater in the loop? The tank heater has an expansion tank, if that's relevant.
Does anyone have any ideas here about what the most straightforward solution to this problem is? We don't need instant hot water, but would certainly like to get it more quickly than we are currently.
As an aside, I suppose it's possible that the NaviCirc we received was bad, and I could get another one and try it out. Is it at all possible that the Navien + NaviCirc would work in this configuration, with the other hot water heater in the loop? The tank heater has an expansion tank, if that's relevant.
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