Rheem RTG-74X User Manual

Tankless Water Heater Recess Box
Installation Instructions
The purpose of this manual is to provide the installer with
the basic instructions necessary to properly install the recess
box. This manual assumes that the installer has basic car-
pentry skills and plumbing knowledge. Local codes may
apply to this installation, all local building, electrical, and
plumbing codes should be followed.
It is imperative that all persons who are expected to install,
operate or adjust this recess box and/or water heater, read
these instructions along with those instructions provided
with the tankless water heater.
Recognize this symbol as an indication of Important
Safety Information!
Refer to the Use and Care Manual provided with your
tankless water heater for the proper installation proce-
dures and conditions.
!
Only these models of Outdoor Tankless Water Heaters
will t or function in this recess box;
RTG-74X GT-199X
RUTG-74X RMTG-74X
PTG-74X PH-28ROF
PH-28COF
WARNING! Gasoline, as well as other ammable materials and liquids (adhesives, solvents,
paint thinners etc.), and the vapors they produce are extremely dangerous. DO NOT handle, use or store
gasoline or other ammable or combustible materials anywhere near or in the vicinity of a water heater
or any other appliance. Be sure to read and follow the labels on the water heater, as well as the warning
printed in this manual. Failure to do so can result in property damage, bodily injury or death.
!
1
Location - This water heater recess box is for OUT-
DOOR installation ONLY, and is intended for use only with
the water heater models listed above. Do not attempt to in-
stall a water heater of another brand or model in this recess
box.
Do not attempt to modify this recess box. Doing so will
alter the intended design potentially causing an unsafe op-
erating condition.
Consult the Use and Care Manual provided with your tan-
kless water heater for installation instructions regarding
a suitable location for the water heater. All guidelines re-
garding clearances and distances from overhangs, windows
and doors, and air inlets into the home must be followed.
Recess Box Clearances - This recess box is designed
to be installed with a Zero (0) clearance to combustibles.
For service and proper operation, 24”(61 cm) of clearance
is required in front of the recess box.
Freeze Protection - To help prevent water lines from
freezing do not locate water heater on the side of a building with
prevailing winter winds. Refer to the Use and Care Manual
provided with your water heater for additional information.
AP14006-1 (12/06)

Rheem RTG-74X Specifications

General

Type	Tankless Water Heater
Fuel Type	Natural Gas
Maximum Flow Rate	7.4 GPM
Energy Factor	0.82
Vent Type	Direct Vent
Temperature Range	98°F - 140°F

Summary

Tankless Water Heater Recess Box Installation Instructions

Important Safety Information

Covers safety symbol and flammable material warnings for safe operation and accident prevention.

Location and Recess Box Guidelines

Details outdoor installation requirements, clearances, and freeze protection for optimal placement.

Water Heater Exhaust Terminal Location

Clearance Requirements for Vent Terminal

Provides detailed clearance specifications for vent terminals based on Canadian and US installation codes.

Additional Location Considerations

Offers additional advice on placement, avoiding patios, shrubbery, and ensuring proper ventilation and snow clearance.

Installation Process Overview

Rough-In Dimensions and Framing

Specifies rough-in dimensions for framing the opening and typical framing methods for the recess box.

Plumbing and Piping Connections

Guides on stubbing pipes, making water and gas connections, and sealing openings to prevent leaks.

Power Disconnect Installation

Details the requirement for installing a weather-resistant power disconnect for unit service and safety.

Final Assembly and Inspection

Thermostat Wiring Procedure

Explains how to route and connect the thermostat wire to the water heater as per manual instructions.

Sealing and Exterior Finish

Covers sealing all openings and joints with sealant to prevent water infiltration and protect the wall.

Door Installation and Security

Guides on installing the outer door and securing it with a clip and padlock for safety and access.