Gas Pressure Regulator; Grounding Instructions; Heater Wiring; Installation Diagrams - A.O. Smith BTR120 Installation Operation & Maintenance

BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR
GAS LEAKAGE. Use soap and water solution or other material
acceptable for the purpose in locating the leaks.
MATCHES, CANDLES, FLAME OR OTHER SOURCES OF
IGNITION FOR THIS PURPOSE.
DISCONNECT THE HEATER AND ITS MANUAL GAS SHUT-OFF
VALVE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY
SUPPLY PRESSURE TESTING EXCEEDING 1/2 PSIG (3.5 kPa).
GAS SUPPLY LINE MUST BE CAPPED WHEN DISCONNECTED
FROM THE HEATER FOR TEST PRESSURES OF 1/2 PSIG
(3.5 kPa) OR LESS. THE APPLIANCE NEED NOT BE
DISCONNECTED, BUT MUST BE ISOLATED FROM THE
SUPPLY PRESSURE TEST BY CLOSING THE MANUAL GAS
Shut-off VALVE.
GAS METER SIZE — NATURAL GASES ONLY
Be sure the gas meter has sufficient capacity to supply the full
rated gas input of the water heater as well as the requirements of
all other gas fired equipment supplied by the meter. If gas meter
is too small, ask the gas company to install a larger meter having
adequate capacity.

GAS PRESSURE REGULATOR

The gas pressure regulator is built into the gas valve and is
equipped to operate on the gas specified on model and rating
plate. The regulator is factory adjusted to deliver gas to burner at
correct water column pressure allowing for a nominal pressure
drop through the controls.
The minimum gas supply pressure for input adjustment must not
be less than 4.5" w.c. (1.12 kPa) for natural gas and 11.0" w.c.
(2.74 kPa) for propane gas.
INSTALLATION DIAGRAMS-TOP INLET/OUTLET USAGE
GENERAL
The type, size and location of the relief valves must be in
accordance with local codes. The locations of the relief valves
shown in the installation diagrams are typical. The heater has a
factory installed high temperature limit switch and temperature
and pressure relief valve.
Cold water lines to heater should be installed as shown in order
to minimize gravity circulation of hot water to building cold water
lines.
A listed temperature and pressure relief valve of adequate capacity
is installed on the heater. The locations shown in the installation
diagrams on the following pages are typical.
The discharge opening of the temperature and pressure relief
valve, located in front of the heater must be piped to an open
drain and should not be subject to freezing temperatures.
Install in accordance with all local codes.
Use of the top inlet water connection requires installation of an
inlet dip tube (refer to figure 11).
heater. Follow caution labels if applying heat to this fitting. Do
not allow pipe dope to contact the plastic tube during installation.
CODE RESTRICTIONS
Use of the top inlet water connection is not permitted on
DO NOT USE
The tube is supplied in the
Do not subject the combination gas valve to inlet gas
pressures of more than 14.0" W.C. (3.48 kPa) - natural gas,
14.0" W.C. (3.48 kPa)- propane gas. A service regulator is
necessary if higher gas pressures are encountered.
Gas pressure specified in Table 5, refer to flow pressure taken at
pressure tap of automatic gas valve while heater is operating.

GROUNDING INSTRUCTIONS

This water heater must be connected to a grounded metal,
permanent wiring system; or an equipment grounding
conductor must be run with the circuit conductors and
connected to the equipment grounding terminal or lead on the
water heater.

HEATER WIRING

All electrical work must be installed in accordance with the current
edition of the National Electrical Code NFPA 70, for Canada use
Canadian Electric Code CSA C22.1 and must conform to all local
code authority having jurisdiction.
IS REQUIRED TO REDUCE RISK OF ELECTRICAL SHOCK OR
POSSIBLE ELECTROCUTION.
For Canadian installations the electrical connections and
grounding shall be done in accordance with current Canadian
Electrical Code CSA C22.1, Part 1 and/or local codes.
If any of the original wire as supplied with the appliance must be
replaced, use only type 105°C thermoplastic or equivalent. 250°C
type F must be used for the flame sensor leads and the spark
ignition cable must be high voltage 250°C.
installations in the state of North Carolina, due to the material of
the tube (Polypropylene). Where such code restrictions exist,
use only lower inlet tank connection. This may also require a
heat trap - check local codes. The "Top Outlet" connection may
still be used on these applications. Plug or cap all unused
openings in the tank before filling with water.
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE
TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE
CONTROL WARNING ON PAGE 27. IF HIGHER PREHEAT
TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE
BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT
WATER SUPPLIED TO FIXTURES.
TUBE INLET INSTALLATION
15
AN ELECTRICAL GROUND
DANGER
FIGURE 13