I am in the process of building a new home and the builder is offering a tankless water heater option. I have talked to some other builders in the area who install the tankless in the conditioned crawl space. My builder says his plumber refuses to do that and they are recommending not putting it in the garage because of noise complaints by previous clients. Any advice and/or information on interior installation or noise levels of tankless heaters would be appreciated.

I am in China, they install ours on the wall in the kitchen, we can hear it turn on, but it is not as loud as the vent over the stove. I have two homes in China and have them in both. My only issue is that if the water volume is low, the unit does not turn on.

I disagree. Tankless heaters are not noisy. There is a subtle humming sound when it turns on. The sound comes from fan discharging fumes. But in any way I would call it "noisy." Tankless heaters are frequently installed inside townhouses and condominiums, few feet from bedrooms and I have never heard anybody to complain about noise.

Call few other plumbers and get second opinion. It almost seems to me your builder's plumber doesn't want to put it in the garage because of some other issues ( like more h/c pipes to run... more vents to run... or the heater is too far from gas meter and he would have to run new gas line... etc.. )

Let me know how you did

Milo

I agree, not noisy. (Maybe a cheap brand of fan?)
I wouldn't want mine in a crawl space because you really want quick and easy access to it, plus a clean area.
I wouldn't want mine far away either - you have to wait a while for the flame to heat the small amount of water right above the flame, and then it has to travel as it keeps heating water flowing above it.
A small interior room is my ideal if you don't have a full cellar. Minimum determined by building code.

I like to know what mine can do and not rely on a plumber to make the choice. There's a lot to know about flow rates for both how much it takes to get the flame started and for how many gallons a minute of hot water you get.
Brand quality varies a lot too.

Neither of mine are noisy and they must be in a conditioned space which never freezes. Where does he want to put it and where is the home located?