Rheem RTGH-95DVELN-3 Use And Care Manual page 24

INSTALLATION INSTRUCTIONS
Venting for Direct-Vent Water Heater
NOTICES:
• It is recommended that the air intake pipe and
exhaust pipe have a 1/4" per foot upward slope
toward the outdoors.
• Maintain the proper clearance between the vent pipe
and combustible or noncombustible materials as
described on page 16.
• Recommend use of condensation trap/collar on
the air intake to prevent water entering the heater
cabinet
• A clearance of 0 in. (0 cm) is allowed between the
vent or air intake pipe and combustible material.
• Use proper support for the vent and air intake pipes.
• It is recommended the support method used isolates
the vent pipe from floor joists or other structural
members. This helps prevent transmission of noise
and vibration.
• DO NOT support, pin, or otherwise secure the venting
system in a way that restricts the normal thermal
expansion and contraction of the chosen venting
material.
See page 25 for additional requirements for the
Commonwealth of Massachusetts.
Preexisting Venting Notes:
If the water heater is being installed as a
replacement for an existing water heater, a
thorough inspection of the existing venting and
air intake system must be performed prior to any
installation work. Verify that the correct materials,
vent lengths, and terminal locations as described
in this manual have been met. Carefully inspect
the entire venting and air intake system for any
signs of cracks or fractures, particularly at the
joints between elbows or other fittings and the
straight runs of vent pipe. Check the system for
signs of sagging or other stresses in the joints as
a result of misalignment of any components in the
system. If any of these conditions are found, they
must be corrected in accordance with the venting
instructions in this manual before completing
the installation and putting the water heater into
service.
24
When the water heater is installed above 2000 ft.
(610 m), the settings on the DIP switch located on
the control board need to be changed per vent
length and altitude. If these settings are not changed,
the water heater may not function properly.
Refer to "Venting for Direct Vent Water Heaters" on
page 22 for the vent lengths at each setting.
NOTICE:
DO NOT alter any other DIP switch settings. The manifold
pressure will be reduced accordingly.
Please contact technical service listed on page 76 of
this use and care manual if you have any questions
of high altitude DIP switch adjustments.
WARNING:
This water heater requires the correct DIP switch
adjustments per vent length and altitude for proper
operation. Incorrect DIP switch adjustments may cause
improper water heater operation resulting in serious injury
or death.
NOTICE:
It is recommend to have a vent length as short as possible.
Input rate at high altitude naturally is derated. In addition
to that, input rate of the water heater decreases more if
there is restriction (pressure drop) in the venting system.
Refer to input rate reduction table due to vent length on
page 23. Actual input rate reduction may be different at
each installation.