John Wood Commercial - AJWSC - Manual (Page 11)

Venting
It is the responsibility of the installing contractor to provide a
vent adequate in capacity and in good usable condition.
Btu/hr capacity limitations are governed by the style and
height of the vent/chimney. Vent piping must be installed in
accordance with all local and provincial or state codes or, in
the absence of such, the latest edition of “Natural Gas and
Propane Installation Code” CAN/CSA-B149.1 (Canada),
or “National Fuel Gas Code” ANSI Z223.1 (NFPA 54)
(U.S.A.).
U.L. recognized fuel gas and carbon monoxide (CO) detec-
tors are recommended in all applications and should be
installed using the manufacturer’s instructions and local
codes, rules, or regulations.
Important: Check to make sure the vent pipe is not blocked
in any way.
• Venting should be as direct as possible with a minimum
number of pipe fittings.
• Exhaust gas vents must be installed with U.L. listed type
B vent pipe according to the vent manufacturer’s instruc-
tions and the terms of its listing.
• Single wall vent connectors must have 152mm (6 in.) of
clearance from unprotected combustible surfaces.
• If sidewall venting is necessary, a power vent kit is
required. For availability contact 1-888-479-8324.
• Vents that run through unconditioned spaces where
below freezing temperatures are expected should be
properly insulated to prevent freezing.
• Existing vent systems must be inspected for obstructions,
corrosion and proper installation.
• Vents must be connected to the water heater’s drafthood
by a certified vent connector or by directly originating at
the drafthood opening.
• Some models are shipped with a vent reducer. The vent
reducer can be installed directly to the drafthood if the
existing vent system is adequately sized to support the
exhaust gases.
• Vertical gas vents must terminate with a listed cap or
other roof assembly and be installed according to their
manufacturer’s instructions.
• Horizontal vent connections must have an upward slope
of at least 21mm per metre (1/4 in per foot).
• Gas vents must be supported to prevent damage, joint
separation, and maintain clearances to combustible
materials.
• Vent connection joints should be fastened by sheet metal
screws or by other approved methods.
• Vent and vent connectors should have adequate support
to keep weight off the drafthood.
All pipe, fittings, and procedures must conform to American
National Standard Institute and American Society for Testing
and Materials (ANSI/ASTM) standards in the United States.
Important: If you lack the necessary skills required to prop-
erly install this venting system, you should not proceed, but
get help from a qualified service technician.
Drafthood/Damper Installation
Install the supplied drafthood and damper on the flue outlet
collar. Use only the supplied drafthood and damper, DO
NOT use any substitute or alter the components in any way.
Place the damper on the water heater (see Figure 5). Align
the four pilot holes on top of the water heater with the 4 cor-
responding holes on the damper bracket and secure with
the supplied screws. Next, align the drafthood legs with the
4 corresponding pilot holes on top of the water heater and
attach securely with the supplied screws. Locate the wiring
from the ECO, and attach it to the wiring harness on the
damper (see Figure 5). Once damper is installed, ensure
that the damper position indicator is visible (See Figure 5).
Flue Outlet Reducer
Some units are shipped with a flue outlet reducer (See
Figure 6). Use only the flue outlet reducer supplied with this
unit. The flue outlet reducer should be connected to the top
of the flue damper and sealed by high temperature silicon.
The vent piping must be installed in accordance with all
local and provincial or state codes or, in the absence of
such, the latest edition of “Natural Gas and Propane
Installation Code” CAN/CSA-B149.1 (Canada), or
“National Fuel Gas Code” ANSI Z223.1 (NFPA 54)
(U.S.A.).
A
1
B
2
BTU/h (kW) mm2 (in2) mm (in) mm (in)
75,000 (23) 7,000 (11) 100 (4) 125 (5)
100,000 (30) 9,000 (14) 100 (4) 125 (5)
125,000 (37) 12,000 (18) 125 (5) 150 (6)
150,000 (45) 14,000 (22) 125 (5) 150 (6)
175,000 (53) 16,000 (25) 150 (6) 175 (7)
200,000 (60) 19,000 (29) 150 (6) 175 (7)
225,000 (68) 21,000 (32) 150 (6) 175 (7)
250,000 (75) 23,000 (36) 175 (7) 200 (8)
275,000 (83) 26,000 (40) 175 (7) 200 (8)
300,000 (90) 28,000 (43) 175 (7) 200 (8)
325,000 (98) 30,000 (47) 200 (8) 225 (9)
350,000 (105) 32,000 (50) 200 (8) 225 (9)
375,000 (113) 35,000 (54) 200 (8) 225 (9)
400,000 (120) 37,000 (58) 225 (9) 250 (10)
Combined input of
all appliances in
confined space
Required
free area of
duct
Acceptable equivalent duct
diameter
Table 4
Notes:
1.
Maximum length of ducts in column A is 6.1 equivalent metres (20
ft).
2. Maximum length of ducts in column B is 15.2 equivalent metres
(50 ft).
WARNING
Do not operate heater with damper in closed
position, it must be in the open position dur-
ing water heater operation. Do not negate the
action of any existing safety or operational
controls.
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