I am contemplating getting a tankless hot water heater, the Noritz NRC98 would be a likely candidate. The obvious install location in my house would be the master bedroom closet as it shares a wet wall with the two bathrooms.

How much noise do these things make? The closet has doors, and the bathroom shower could be louder than a hot water heater. But I have never had one, so it makes sense to ask about the noise factor.