Rheem RTG-53X, RMTG-53X, RUTG-53X, PTG-53X, PH-20ROF Installation Instructions Manual

Tankless Water Heater Recess Box

Installation Instructions

Only these models of Outdoor Tankless Water Heaters

will t or function in this recess box;

RTG-53X RUTG-53X
RMTG-53X PTG-53X
PH-20ROF

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 car­pentry 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 pro­vided with the tankless water heater.

!

Refer to the Use and Care Manual provided with your
tankless water heater for the proper installation proce­dures and conditions.

!

WARNING!

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.

Gasoline, as well as other ammable materials and liquids (adhesives, solvents,

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 tank­less water heater for installation instructions regarding a
suitable location for the water heater. All guidelines regard-

Recognize this symbol as an indication of Important
Safety Information!

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 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.

1

AP14133 (12/06)

Recess Box Location - This water heater recess box is intended for an outdoor location only. Follow the

(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)

guidelines below or in the Use and Care Manual provided with the water heater for choosing a suitable location.

G

v

A

D

E

V

B

V

L

C

FI

v

L

C

P

O

v

F

B

B

D

E

X

D

E

S

O

B

E

L

B

A

R

E

I

F

E

L

L

C

B

A

R

E

P

O

v

v

J

B

A

H

C

D

v

E

X

D

E

S

O

X

I

M

v

X

K

Figure 1

VENT TERMINAL

V

AIR SUPPLY INLET

X

AREA WHERE TERMINAL IS NOT PERMITTED

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.

Canadian Installations

Indoor and Outdoor

A= Clearance above grade, ve-

randa, porch, deck or balcony.

B= Clearance to window or door

that may be opened.

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/regu­lator assembly.

I = Clearance to service regulator

vent outlet.

J = Clearance to nonmechanical

air supply inlet to building or
the combustion air inlet to any
other appliance.

K = Clearance to mechanical air

supply inlet.

L = Clearance above paved

sidewalk or paved driveway
located on public property.

M = Clearance under veranda,

porch, deck or balcony.

1

In accordance with current CAN/CGA-B149 Installation Code

2

In 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.

12 inches (30 cm) above antici­pated snow level.

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).

* *

* *

* *

* *

* *

3 feet (91 cm) within a height 15
feet (4.57 m) above the meter/regu­lator assembly.

3 feet (91 cm)

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 feet (1.83 m) 3 feet (91 cm) above if within 10

Not Allowed Not Allowed

Not Allowed Not Allowed

1

US Installations

Outdoor

12 inches (30 cm) above antici­pated snow level.

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).

*

*

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)

feet (3 m) horizontally.

2

Figure 2

WARNING: Moisture in the flue gas will condense as it

leaves the vent terminal. In cold weather this condensate can

2

freeze on the exterior wall, under the eaves and on
surrounding objects. Some discoloration to the exterior of
the building is to be expected. However, improper location
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 freez­ing 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 pre­vailing winter winds.

4. Do not locate water heater too close
to shrubbery, as ue gases may dam­age them.

5. Caulk all cracks, seams and joints
within six (6) feet (1.8 m) of exhaust
vent.

6. Guard exhaust vent against acciden­tal contact with people and pets.

7. Install the water heater such that the
air inlet and exhaust vent are above
anticipated snow levels