Water Heater Installation; Condensate Drain Installation; Gas Piping; Sediment Traps - A.O. Smith 300 Series Instruction Manual

CONDENSATE DRAIN INSTALLATION

Installation must conform with these instructions and local building
codes.
Field supplied materials required for installation include:
Approved PVC cement and PVC primer.
•
1/2 inch PVC pipe - minimum length to equal the distance
•
between the water heater and a suitable building drain.
1/2 inch PVC fittings (elbows, couplings, and adapters)
•
necessary to install a condensate drain line between the Exhaust/
Condensate Elbow Assembly and a suitable building drain.
Floor mounted standoffs to brace the drain line.
•
INSTALLATION NOTES
The condensate drains from the water heater's covered by
1.
this instruction have PH levels between 4.3 and 5.0. Install a
commercially available neutralizing kit if required by local codes.
Lower pH levels are acidic. Do not connect a metal condensate
drain line, such as copper pipe, to the water heater for this reason.
The field installed condensate drain line must not be less than
2.
1/2 inch PVC in size.
3. THE EXHAUST ELBOW HAS A BUILT IN CONDENSATE
TRAP. DO NOT INSTALL AN ADDITIONAL TRAP IN THE
CONDENSATE DRAIN PIPING. DO NOT remove, modify or
alter the factory condensate trap.
EXHAUST/CONDENSATE
(VENT) ELBOW
PRESSURE PORT

GAS PIPING

Make sure gas supplied is same type listed on model rating plate. The
inlet gas pressure must not exceed 14 inch water column (3.5 kPa)
for natural and propane gas (L.P.). The minimum inlet gas pressure
shown on rating plate is that which will permit firing at rated input.
Schedule 40 Steel or Wrought Iron Pipe is the preferred material for
the gas line of this water heater. It is imperative to follow the sizing
recommendations in the latest version of the Natural Gas and Propane
Code if Corrugated Stainless Steel Tubing (CSST) is used as the gas
line for this water heater.

WATER HEATER INSTALLATION

WATER HEATER INSTALLATION
1/2" NPT
CONDENSATE
DRAIN
CONNECTION
CONDENSATE
CLEANOUT
Figure 42. Condensate Drain Installation
INSTALLATION INSTRUCTIONS
Ensure the water heater's Enable/Disable switch is in the
4.
"Disable" position.
Install a 1/2 inch PVC condensate drain line between condensate
5.
drain connection on the Exhaust/Condensate Elbow and a
suitable building drain. The condensate line must slope to an
open drain. See Figure 42.
Terminate the condensate drain piping with an elbow above the
6.
drain. Ensure that any discharge will exit the condensate drain
line no more than 6 inches (15.2 cm) above a suitable building
drain, or external to the building. See Figure 42.
Note: In cold climates it is recommended the condensate drain
be terminated at a suitable drain inside the building.
Ensure the condensate drain line is not elevated above the
7.
condensate drain connection on the Exhaust/Condensate Elbow.
See Figure 42.
Brace the condensate drain line with floor-mounted standoffs
8.
every three feet.
Ensure that the condensate drains freely during start up. See
9.
Start Up (page 51).
10. Condensate clean out cap must be on and tight when unit is in
operation.
CONDENSATE DRAIN
LINE - FIELD
INSTALLED
BUILDING
DRAIN

SEDIMENT TRAPS

Fire and Explosion Hazard
• Contaminants in gas lines can cause fire
or explosions.
• Clean all gas piping before installation.
• Install drip leg in accordance with NFPA
54 or CSA-B1491.
A sediment trap shall be installed as close to the gas inlet of the
water heater as practical at the time of water heater installation.
The sediment trap shall be either a tee fitting with a capped nipple
in the bottom outlet or other device recognized as an effective
sediment trap.
35
DRAIN LINE TO
TERMINATE NO
MORE THAN 6
INCHES (15.2 cm)
ABOVE DRAIN