Just installed a Nortiz N069M-OD tankless water heater, located on an exterior wall, home in So. Calif. When I run the shower (the Noritz is on the other side of the shower, I can hear very well what it’s ‘doing’) at 5:30 am with no other water being used in the house, the damn thing makes noises almost repeatedly for 2 minutes or so, then calms down. The noise is described as some valve opening or closing in the unit, kinda a rattling sound, its the same noise I hear when I turn on the hot at a nearby sink, but it rattles alot more when the shower is used. The water temp changes noticebably while it’s doing this 20-30 or so valve opening or closings over the about 2 minute period.
The water pressure at a nearby hose bib measure an average of 77.3 psi. I used 3 Home Depot water pressure gauges, they measured 76, 76 and 80 psi for an average of 77.3 My plumber thought maybe the unit was getting hit with too much pressure, his $14 pressure gauge read 92 psi which made us think we were hitting it with too much pressure, so who’s gauges are correct.
Also, I can shut off the tub cold near by and force a watter hammer that makes the same chatter noise in the Nortiz, but not the 2 minute continious action like the shower does. The shower valve is a Grohe single handle type, the auto balance type to keep one from getting real hot water when someone else flushes the toliet while another is in the shower. If we shut off the cold on the tub slowly there is no hammer and no noise in the Noritz. Same thing with the sprinklers, but only when the electric solenoids shut off, a classic water hammer.
I have new 1.25 inch copper and 1.25 inch gas lines from the water and gas meter at the street 60 feet from the Noritz, which feed the house and the Noritz. The Nortiz gets fed with soft water from a bottle 2 feet away. So, anyone know what all the noise is from the Noritz during the shower ? It’s like it’s having a hard time setting an exact temp, I must be at a weak point on their control loop or something ?? The outdoor temp has been in the upper 30F lately and haven’t checked for it during the day at 70F.
thanks !
Replies
Also, I can shut off the tub cold near by and force a watter hammer that makes the same chatter noise in the Nortiz, but not the 2 minute continious action like the shower does. "
There are two different types of plumbing noise.
True water hammer happens when fast moving water is quickly shut off. The water wants to keep moveing and it "slams" into the valve. It will cause a BANG followed by a couple of rattles of the pipes, depending on the how well the pipes are mounted. It is made worse with high pressure as that often means higher flow rates.
It can be fixed with a hammer arrestor close to the valve.
The other is caused by "something" that is in the flow of water so that was the water flows it moves and partically blocks the flow of water. With the water flow resticted the "something" moves back allow more flow.
This is continously repeated and DEPENDING it can be anything from screaching noise, to a woodpecker sound, to machine gun sound.
What is most common in that the washer in the faucet is loose. But it can also be a washer in the stop valve or even main shutoff.
And it can be other debre such as excss soilder that has formed inside the pipe.
I really don't know aobut the WH so I don't know if it has anything in it that is suppose to move. But it could be debre or a shutoff valve next to the WH.
Try shutting off the gas and seeing if it still makes noise.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.