Hi guys. I just bought a 2-story house with a Navien NPE 240A in the basement. The water heater has a variety of issues. The kitchen sink gets great water pressure and heat. The Navien is set to 120 and the kitchen sink is probably about 120. The first floor bathroom sink gets lukewarm and stays that way. The first floor bathroom shower gets fairly hot, then tapers off to cool, then warms up again and repeats that 5 or 5 times during a shower. Both of these fixtures in the bathroom have mediocre water pressure. It's not terrible, but not great, either.
The second floor bathroom - the furthest fixture from the Navien - seems to be fairly consistently hot (maybe gets to 120) in both shower and sink faucet and it's hot very quickly, which based on my reading, may mean that the system uses the built-in recirculating pump and dedicated recirculating return line to get hot water to the furthest fixture for "instant" hot water. But the recirculating pump is set to the 6:00 position, which means that it's off, if I'm reading correctly.
Next, the bottom of the heat exchanger has some kind of oily condensation (as referenced here: https://terrylove.com/forums/index.php?threads/navien-npe-240a-ng-leaking.70239/). I assume this is a a separate issue. In that thread, someone referenced a potential venting issue as the cause, but I suspect that's not the problem. I understand that Navien will replace the exchange under warranty, but I guess I'd be out a lot of money for installation if I chose that route.
I cleaned out the air filter, the cold water intake filter and the recirculation inlet filter, all of which needed to be cleaned but were not terribly dirty. I examined the check valve, which I've read can break, but it appeared (to my untrained eyes, at least) to be fine. I thought about buying a replacement check valve anyway because it's only about $6 and it's an easy fix.
Others have complained about broken flow sensors. They are about $50 and seem fairly easy to replace. I guess i could try that if you guys think it may be the issue. Is there a way to test if the flow sensor is working?
I left the recirc pump at the 6:00 (off) position and set the dip switches to all down except for #2, which is up. [Incidentally, I may have damaged the #2 dipswitch by flipping it up with a screwdriver. I wasn't sure what to use and they are pretty delicate.] I've also tried #1 up and the rest down, but it didn't seem to make any difference (though I didn't check the second floor after I made that change).
I'd appreciate any suggestions you may have. Thank you!
The second floor bathroom - the furthest fixture from the Navien - seems to be fairly consistently hot (maybe gets to 120) in both shower and sink faucet and it's hot very quickly, which based on my reading, may mean that the system uses the built-in recirculating pump and dedicated recirculating return line to get hot water to the furthest fixture for "instant" hot water. But the recirculating pump is set to the 6:00 position, which means that it's off, if I'm reading correctly.
Next, the bottom of the heat exchanger has some kind of oily condensation (as referenced here: https://terrylove.com/forums/index.php?threads/navien-npe-240a-ng-leaking.70239/). I assume this is a a separate issue. In that thread, someone referenced a potential venting issue as the cause, but I suspect that's not the problem. I understand that Navien will replace the exchange under warranty, but I guess I'd be out a lot of money for installation if I chose that route.
I cleaned out the air filter, the cold water intake filter and the recirculation inlet filter, all of which needed to be cleaned but were not terribly dirty. I examined the check valve, which I've read can break, but it appeared (to my untrained eyes, at least) to be fine. I thought about buying a replacement check valve anyway because it's only about $6 and it's an easy fix.
Others have complained about broken flow sensors. They are about $50 and seem fairly easy to replace. I guess i could try that if you guys think it may be the issue. Is there a way to test if the flow sensor is working?
I left the recirc pump at the 6:00 (off) position and set the dip switches to all down except for #2, which is up. [Incidentally, I may have damaged the #2 dipswitch by flipping it up with a screwdriver. I wasn't sure what to use and they are pretty delicate.] I've also tried #1 up and the rest down, but it didn't seem to make any difference (though I didn't check the second floor after I made that change).
I'd appreciate any suggestions you may have. Thank you!