Rheem RTG-66X 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 very important 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 pro-
vided 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-66X RUTG-66X
RMTG-66X ECO-180X
PH-25ROF
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 install 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
operating condition.
Consult the Use and Care Manual provided with your tank-
less water heater for installation instructions regarding a
suitable location for the water heater. All guidelines regard-
ing clearances and distances from overhangs, windows and
doors, and air inlets into the home must be followed.
Recess Box Clearances - This recess box is de-
signed to be installed with a Zero (0) clearance to combus-
tibles. 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 build-
ing with prevailing winter winds. Refer to the Use and
Care Manual provided with your water heater for addi-
tional information.
AP14935 (10/08)
AP14935 Recess Box 66x.indd 1 10/7/2008 10:11:05 AM

Water Heater Exhaust Terminal Location
The following information should be used for determining the proper location of
the vent terminal for outdoor tankless water heaters.
WARNING: Moisture in the flue gas will condense as it
leaves the vent terminal. In cold weatherthis condensate can
freeze on the exterior wall, underthe eaves and on
surrounding objects. Some discoloration to the exterior of
the building is to be expected. However, improperlocation
or installation can result in severe damage to the structure
or exterior finish of the building
Additional Considerations
1. Do not install water heater under
any patio or deck.
2. To help prevent moisture from freez-
ing on walls and under eaves, do not
locate the water heater on the side
of a building with prevailing winter
winds.
3. To help prevent water lines from
freezing do not locate water heater
on the side of a building with pre-
vailing winter winds.
4. Do not locate water heater too close
to shrubbery, as ue gases may dam-
age them.
5. Caulk all cracks, seams and joints
within six (6) feet (1.8 m) of exhaust
vent.
6. Guard exhaust vent against acciden-
tal contact with people and pets.
7. Install the water heater such that the
air inlet and exhaust vent are above
anticipated snow levels
Recess Box Location - This water heater recess box is intended for an outdoor location only. Follow the
guidelines below or in the Use and Care Manual provided with the water heater for choosing a suitable location.
Figure 1
Figure 2
D
V
V
E
FIXED
CLOSED
OPERABLE
O
PERABLE
FIXED
CLOSED
v
v
B
L
F
C
B
v
vv
X
B
B
B
A
J
C
I
H
X
v
M
K
v
G
A
V
VENT TERMINAL XAIR SUPPLY INLET AREA WHERE TERMINAL IS NOT PERMITTED
2
(1.8 m)
If soffit vent is too close,
block off and install new
vent at another location
Inside
corner
Caulk
Caulk
Caulk
6' (1.8 m)
caulk zone or to edge of
window etc., starting
within 6' (1.8 m)
Rising moisture will collect under eaves
4'
6' (1.8 m) caulk
zone
6'
(1.2 m)
12”
(30 cm)
Canadian Installations1
Indoor and Outdoor
US Installations 2
Outdoor
A= Clearance above grade, ve-
randa, porch, deck or balcony.
12 inches (30 cm) above antici-
pated snow level.
12 inches (30 cm) above antici-
pated snow level.
B= Clearance to window or door
that may be opened.
6 inches (15 cm) for appliances ≤
10,000 Btuh (3 kW), 12 inches (30
cm) for appliances > 10,000 Btuh
(3kW) and ≤100,000 Btuh (30kW),
36 inches (91 cm) for appliances >
100,000 Btuh (30kW).
6 inches (15 cm) for appliances
≤ 10,000 Btuh (3 kW), 9 inches
(23 cm) for appliances > 10,000
Btuh (3kW) and ≤ 50,000 Btuh
(15kW), 12 inches (30 cm)
for appliances > 50,000 Btuh
(15kW).
C= Clearance to permanently
closed window. * *
D= Vertical Clearance to venti-
lated soft located above the
terminal within a horizontal
distance of 2 feet (61 cm)
from the center line of the
terminal.
* *
E= Clearance to unventilated
soft. * *
F= Clearance to outside corner. * *
G= Clearance to corner. * *
H = Clearance to each side of cen-
ter line extended meter/regu-
lator assembly.
3 feet (91 cm) within a height 15
feet (4.57 m) above the meter/regu-
lator assembly. *
I = Clearance to service regulator
vent outlet.
3 feet (91 cm) *
J = Clearance to nonmechanical
air supply inlet to building or
the combustion air inlet to any
other appliance.
6 inches (15 cm) for appliances
≤10,000 Btuh (3 kW), 12 inches
(30 cm) for appliances > 10,000
Btuh (3kW) and ≤ 100,000 Btuh
(30kW), 36 inches (91 cm) for ap-
pliances > 100,000 Btuh (30kW).
6 inches (15 cm) for appliances
≤10,000 Btuh (3 kW), 9 inches
(23 cm) for appliances > 10,000
Btuh (3kW) and ≤ 50,000 Btuh
(15kW), 12 inches (30 cm) for
appliances > 50,000 Btuh (15kW)
K = Clearance to mechanical air
supply inlet.
6 feet (1.83 m) 3 feet (91 cm) above if within 10
feet (3 m) horizontally.
L = Clearance above paved
sidewalk or paved driveway
located on public property.
7 feet (2.13 m) *
M = Clearance under veranda,
porch, deck or balcony. Not Allowed Not Allowed
1In accordance with current CAN/CGA-B149 Installation Code
2In accordance with current ANSI Z223.1/NFPA National Fuel Gas Code.
* If clearances are not specied, then follow local installation codes and the requirement of the gas supplier.
** For condensing appliances: The vent for this appliance shall not terminate over public walkways, near soft
vents, crawl space vents, or other areas where condensate or vapor could create a nuisance, hazard or cause
property damage, or where condensate or vapor could cause damage or could be detrimental to the operation
of regulators, relief valves or other equipment.
AP14935 Recess Box 66x.indd 2 10/7/2008 10:11:05 AM

Rough In Dimensions
Height 39 1/2”; Width 15”; Depth depends upon siding on
home.
Installation
The recess box is designed to be installed with a variety of
home exterior products for new or existing construction.
Choose a suitable location for the water heater and1.
recess box. Follow the guidelines listed on page 2 of
this manual, or the Use and Care Manual for the water
heater, regarding location and clearances. Frame an
opening in the exterior wall of the home for the rough
in dimensions in Figure 3. Local building codes and
standard building practices should be followed.
Install the recess box into the opening. Level and2.
square the box. Test fit the outer door to make
sure it does not bind during installation. Secure
the recess box to the framing on each side using
four or more self tapping screws (not provided).
Mount the water heater into the recess box. In the back3.
of the recess box is a channel to support the bottom
mounting bracket of the water heater. At the top is a
retaining stud for securing the top mounting bracket.
Lift the water heater up and slide the bottom mounting
bracket down into the channel. While holding the water
heater in place, secure the top of the unit to the retain-
ing stud with the washer and nut provided.
Plumbing and Piping - See Figure 5 for Pipe Locations.
Follow all instructions in the Use and Care Manual for instal-
lation of gas and water lines. Holes are provided in the bot-
tom of the recess box for all piping and wiring. These holes
line up with the ttings on the bottom of the water heater.
Stub the water lines and gas pipe up through the bottom1.
of the box (See Figure 5). It is recommended that shut
off valves and unions be installed in the piping for
future service requirements.
Connect the water lines and gas piping to the water2.
heater in accordance with the instructions in the Use
and Care Manual provided with the water heater.
Seal the holes around the piping with a silicone based3.
sealant to prevent any water from leaking into the
wall behind the recess box. Insulate pipes with foam
insulation.
Power Disconnect - Install a suitable means to discon-
nect power from the unit for service. This disconnect should
be weather resistant and meet any and all local codes. In the
absence of local codes, the National Electrical Code should
be followed. Refer to the Use and Care Manual for instruc-
tions in connecting the power to the water heater.
A
B
C
D
E
F
Dimensions - Figure 3
Dim.* Inches
A 38 1/2”
(98 cm)
B 14 3/4
(37 cm)
C 8 1/2”
(21.5 cm)
D 1
(2.5 cm)
E 41
(104 cm)
F 18 3/4
(48 cm)
* Approximate
Cripple Stud
King Stud Trimmer Stud
Blocking
Header
Wall Stud
Sill
Typical Framing - Figure 4
3
Hot Water
Line
Thermostat
Wiring
Opening
Electrical
Opening
Relief Valve
Drain
Gas Line
Cold Water
Line
Plumbing and Piping Openings - Figure 5
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Thermostat Wiring - A hole is provided for
the Thermostat wire(s). Route the wire through the
hole and connect the wire to the water heater accord-
ing to the instructions in the Use and Care Manual.
Final Assembly and Inspection - Follow the
Use and Care Manual for complete details about the water
heater. Check all water and gas connections for leaks.
Seal all openings around pipes and wires with an outdoor
grade silicone sealant. Seal the joint between the recess box
and the siding or brick of the house with a silicone based seal-
ant to prevent water from getting behind the box into the wall.
Installing the Door - Lift the door up from the bot-
tom at a slight angle. Slip the door into the channel at the
top of the recess box. Next push the bottom of the door
ush with the recess box and slide down into the channel
at the bottom of the enclosure. Do not block any air open-
ings on the door.
Security Clip - Before installing the door, slide the
clip into the slot at the bottom of the door from the back-
side so it points straight down through the bottom of the
door. Lift the door into place per the instruction above. As
the door is being slid down into place, guide the security
clip into the slot in the bottom channel of the recess box.
Once the clip is in place, secure with a suitable means
(small padlock, security tag, etc.).
Caulk Joint Between Siding and
Recess Box
Seal all openings around pipes
and wires with a silicone sealant
Sealing and Finish - Figure 8
Drip Ledge
Outer Door
Caulk Joint Between Siding
and Recess Box
Siding or Brick
Security Clip - Figure 9
Padlock
Outer Door
Security Clip
Warning - All openings in the bottom of the recess box
must be sealed to prevent water inltration in to the wall. Fail-
ure to do so could result in damage to the wall.
!
Typical Installation - Figure 6
Recess Box
Wall Sheathing
(Brick, Vinyl, etc)
Outdoor
Tankless Water
Heater
Isolation
Valves
Power
Disconnect
Pressure
Relief Valve
Gas Service
Valve
Thermostat
Wire
Typical Installation and Finish - Figure 7
Drip Ledge
Siding or Brick
Recess Box
Brick Lintel
Lap Siding Brick Siding
4
AP14935 Recess Box 66x.indd 4 10/7/2008 10:11:06 AM