Rheem Tankless Water Heater User Manual

A fire stop plate should be installed at every
penetration of a floor or ceiling if the vent is
not running in a fire-rated shaft. Maintain the
recommended air space clearance to
combustible materials and building insulation.

Once the vent terminal location has been
determined, make a hole through the roof and
interior ceiling to accommodate the vent pipe.
Complete the vent pipe installation to the
water heater’s vent connector fitting on the
water heater vent collar outlet. Support
vertical or horizontal runs as previously
mentioned. If required, use silicone sealant 
at the point the vent connector joins the 
water heater.

Install adequate flashing where the vent pipe
passes through the roof. Determine the vent
terminal height and install the vent pipe
accordingly. Refer to the diagram above for
proper vent terminal height. Connect vent
elbow onto vertical pipe through roof.
Connect short piece of vent pipe
(approximately 6” long [15 cm]) to 
elbow, and the terminal elbow with the
protective screen.

The vent roof system must terminate at least
1 foot (30 cm) above the roof line and at least
2 feet (61 cm) higher than any portion of the
building within 10 feet (3 m).

Install supports every 5 feet (1.5 m) vertically
along the vent pipe route. Vertical supports

are required after every
transition to vertical and are
required after every offset elbow.
When the vent is free-standing
and penetrates a roof/ceiling,
another means of support must
be used at a second location.

Follow the vent manufacturer’s
recommended installation
instructions provided with the
vent purchased from the
manufacturer. 

Chase Requires
6" (15 cm) Clearance
to Combustibles

Firestop

Firestop

Roof Jack

Adjustable
Roof Flashing

Vent
Adapter

3" (8 cm) Clearance

Support
Hanger

Condensate

Trap

To Drain. Dispose of

condensate in accordance

with local codes

Storm
Collar

Support
Clamp

1/4" per foot upward slope

2'

(61 cm)

Max

The location of the vent terminal depends on the following
minimum clearances and considerations (see diagram at left):

Minimum twelve (12) inches (30 cm) above roof.

2

Minimum twelve (12) inches (30 cm) above anticipated
snow level.

Maximum twenty-four (24) inches (60 cm) above roof level
without additional support for vent.

Four (4) feet (1.2 m) from any gable, dormer or other 
roof structure with building interior access (i.e., vent,
window, etc.).

Ten (10) feet (3 m) from any forced air inlet to the building.
Any fresh or make-up air inlet such as a dryer or furnace
area is considered to be a forced air inlet.

3

Min. 12" (30 cm)
Above Roof

1

Min. 12" (30 cm)
Above Anticipated
Snow Level

Max. 24" (60 cm)
Above Roof (Without
Additional Support)

Vent Pipe
Through Roof

Elbow

Termination Elbow
w/ Protective Screen

Small (6” min) (15 cm)
section of vent

15

Chase Requires
6" (15 cm) Clearance
to Combustibles

Firestop

Firestop

Roof Jack

Rain Cap

Adjustable
Roof 
Flashing

Vent
Adapter

3" (8 cm) Clearance

Support
Hanger

Condensate

Trap

To Drain. Dispose of

condensate in accordance

to local codes

Storm
Collar

Support
Clamp

1/4" per foot upward slope

2'

(61 cm)

Max

Vent Pipe

Vent Pipe

2

For installations in Canada 18” (45.7 cm).

3

For installations in Canada 6´ (1.8 m).

1

Min. 18” (46 cm) above roof for installations. in
Canada.