Installation Check; Air Supply/Exhaust; Installation Environment; Gas Supply Piping - Noritz NR50-OD Service Manual

9. Installation Check

Installation problems can cause the unit to work unsatisfactorily. If the unit is not working properly, but there are
no error codes or evidence of malfunction, check the installation.
<Installation Checks>
Altitude
1. If this water heater is installed in a location where the altitude is greater than 2000 ft., the combustion may
become abnormal because of the thinness of the air. The unit must be configured for high elevation
installations by disconnecting the "High Elevation Disconnect" jumper located inside of the water heater. Refer
to the"Installation Manual" for detailed instructions.

Air Supply/Exhaust

1. Make sure that the installation location provides sufficient combustible air and enough space for an exhaust vent.
2. Install the venting only as outlined in the installation manual.

Installation Environment

1. If this unit will be installed in a factory, salon, or laundry service, install it in a location where it will not be
exposed to steam, ammonia, sulfur, chlorine, ethylene compounds, or acids.
2. If this unit will be installed in a restaurant, locate it so that it will not be effected by steam.
3. Avoid any installation that will expose the unit to steam or moisture.
For Multiple Floor Water Supply
1. If the unit will be installed on the lower floor of a multiple story building, in order to get the maximum flow rate
through the unit, there must be at least 29 PSI of water pressure at the inlet to the unit. If this supply water
pressure cannot be maintained, install pumps to increase the pressure and install a pressure gauge to adjust
the supply pressure to the desired level. If the supply pressure to the water heater falls below this level, boiling
may occur in parts of the heat exchanger, causing an abnormal sound and possibly damaging the water
heater.
Installation of Strainer
1. If the unit will be installed in a system with a circulating or pressure increasing pump, install a strainer with a
#50 or greater mesh to protect the unit from damage caused by debris in the plumbing line. This is especially
important for older piping.
<Installation Cautions>

Gas Supply Piping

Because a large quantity of gas is used with these appliances, make sure to size the gas meter and supply
piping to match the maximum Btu rating of the heater.
Air Supply and Vent Pipe
Before installation, note the following:
Vent pipe diameters and maximum vent length:
Vent Pipe Diameter
Maximum Vent Length
*Refer to venting specifications for other configuarations.
For all -DV models, refer to the installation manual for proper venting configurations.
Make sure the installation location allows for a flue to be built that will be shorter than the maximum
allowable vent length.
* A longer vent will cause a danger of explosion.
Choose a good path for the vent pipe.
Do not penetrate the vent pipe through a fire wall.
Extend the vent pipe all the way to the outdoors.
Steam and condensed water may exit the vent pipe. Be sure to install the vent pipe so that the steam
and water droplets will not harm anything.
The neutralizer unit can be filled before connecting the vent pipe.
ø 4 inches
15 feet with 3- 90° elbows*
94