Replaced a 14 year old 75 gal hot-water heater about 6 weeks ago. We decided to go tankless. Did a bunch of research and landed on Noritz. Found a local 5-star recommended installer on Noritz website, got his quote, and went for it.
Ever since the very first day it was installed, we've heard our pipes bumping and thumping at pretty much all hours of the day and NIGHT (omg, the night). The pattern is very irregular. You might hear nothing for 5 minutes and then 3 thumps in a minute. It's a fairly muted thump but it might as well be a sledgehammer after 10 pm when the house is dead quiet. I've heard real "water hammer" before this is not as bad.
My installer has insisted that I have crossover in my hot/cold pipes and this has the Noritz unit in a frenzy trying to keep up with the fluctuations in temperature. I've replaced all 5 single handle shower cartridges and isolated the crossover problem to the kitchen sink. I turned off the water supply below the kitchen sink a few nights ago...which meant, "no crossover anywhere in the house". Still, the thumping persisted. So much for that theory (at least, in my opinion).
This weekend, I got the Noritz manual out and figured out how to disable the recirculation function altogether (and disabled it). Guess what? Silence, wonderful silence. The bad news is that we have to wait 10 minutes for a hot shower (completely unacceptable waste!!).
My installer basically refuses to believe that the problem is due to the Noritz unit. As if they're infallible or something. Installer believes the hot/cold "crossover" at my kitchen sink single handle faucet is the source of the noise in the pipes. The crossover existed before the Noritz install so why was there no thumping in the past?
My opinion is the Noritz unit is defective in some way and needs to be replaced. Please help...I really don't want to go back to a big dumb tank.
Some background data that might help:
Noritz NRCP982-DV NG (w/built in recirculation pump)
House is fully plumbed with recirculating hot water line throughout house.
House is 14 years old. 2 stories (no basement). 5.5 baths.
Ever since the very first day it was installed, we've heard our pipes bumping and thumping at pretty much all hours of the day and NIGHT (omg, the night). The pattern is very irregular. You might hear nothing for 5 minutes and then 3 thumps in a minute. It's a fairly muted thump but it might as well be a sledgehammer after 10 pm when the house is dead quiet. I've heard real "water hammer" before this is not as bad.
My installer has insisted that I have crossover in my hot/cold pipes and this has the Noritz unit in a frenzy trying to keep up with the fluctuations in temperature. I've replaced all 5 single handle shower cartridges and isolated the crossover problem to the kitchen sink. I turned off the water supply below the kitchen sink a few nights ago...which meant, "no crossover anywhere in the house". Still, the thumping persisted. So much for that theory (at least, in my opinion).
This weekend, I got the Noritz manual out and figured out how to disable the recirculation function altogether (and disabled it). Guess what? Silence, wonderful silence. The bad news is that we have to wait 10 minutes for a hot shower (completely unacceptable waste!!).
My installer basically refuses to believe that the problem is due to the Noritz unit. As if they're infallible or something. Installer believes the hot/cold "crossover" at my kitchen sink single handle faucet is the source of the noise in the pipes. The crossover existed before the Noritz install so why was there no thumping in the past?
My opinion is the Noritz unit is defective in some way and needs to be replaced. Please help...I really don't want to go back to a big dumb tank.
Some background data that might help:
Noritz NRCP982-DV NG (w/built in recirculation pump)
House is fully plumbed with recirculating hot water line throughout house.
House is 14 years old. 2 stories (no basement). 5.5 baths.