John Wood Superflue Power Vent User Manual

PART NO. 186714-000 REV. A (08-05)

WARNING:

If the information in these instructions is
not followed exactly, a fire or explosion
may result causing property damage, per­sonal injury or death.

WARNING:

Improper installation, adjustment, alter­ation, service, or maintenance can cause
injury or property damage. Refer to this
manual. For assistance or additional infor­mation, consult a qualified installer, serv­ice agency, or the gas utility.

FOR YOUR SAFETY

• Do not store or use gasoline or other
flammable vapours and liquids in the
vicinity of this or any other appliance.

• Installation and service must be per­formed by a qualified installer, service
agency or the gas utility.

• Do not try to light any appliance.

• Do not touch any electrical switch; do
not use any phone in your building.

• Immediately call your gas supplier from
a neighbor’s phone. Follow the gas
supplier’s instructions.

• If you cannot reach your gas supplier,
call the fire department.

WHAT TO DO IF YOU SMELL GAS

GSW Water Heating is a division of
A. O. Smith Enterprises Ltd.

POWER VENTED GAS

FIRED WATER HEATER

INSTALLATION AND OPERATING INSTRUCTIONS

Read these instructions thoroughly before starting

– 2 –

This page intentionally left blank. May be used for notes or to record other installation information.

– 3 –

TABLE OF CONTENTS

Replacement Parts Listing/

Clearance to Combustibles . . . . . . . . . . . . . . . . . 4

I) INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

User Responsibilities 5

II) SAFETY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

For Installations in Canada: 6
For Installations in the United States: 6
Safety Warning (Flammable Vapours) 6
Safety Warning (Scalding) 6
Safety Warning (Carbon Monoxide) 6
Relief Valve Requirements (T&P) 7

III) INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Unpacking the Water Heater 7
Location Requirements 7

In Earthquake Zones
Clearances and Accessibility 8
Gas Supply 8

Gas Supply Pressure

Gas line purging

Gas Leak Testing

Gas Operating Pressures
Air Requirements 9

General
Combustion Air “Supply” Ducts 9
Louvers and Grilles 9
Air Requirements 10
Confined Space Air Requirements for Canadian
Installations 10
Confined Space Air Requirements for U.S.
Installations 11
Exhaust Venting 12

Important Notes and Warnings

Venting terminations and sizing

Venting instructions

Vent pipe connection to blower
Water Supply 16

Piping Installation

Filling the Water Heater

Closed System/Thermal Expansion
Temperature and Pressure (T&P) Relief Valve 17

The Temperature and Pressure Relief Valve:

The Discharge Line/Driptube:
Electrical Supply 18
Installation Checklist 19

IV) OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . 21

Temperature Regulation 21
Mixing Valves 21
Lighting Instructions
(Robertshaw) 22

Gas Control/Thermostat

Putting the Heater into Service

Temperature Adjustment

Heater Shutdown

Water Heater Operation

Lighting Instructions
(White-Rodgers Intelli-Vent

TM

)24
Gas Control/Thermostat
Putting the Heater into Service
Temperature Adjustment
Heater Shutdown
System Error Codes
Intelli-VentTMSystem Error Codes

V) OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Performance Checks 28

Burner Manifold Pressure
Checking Input
Checking burner flame

VI) SERVICE AND MAINTENANCE. . . . . . . . . . . . . . 28

Not Enough or No Hot Water
Energy Cut-off Control (ECO)
Water is Too Hot
Hot Water Odour
Discoloured Water
Water Heater Makes Noise
Extended Non Use Service
Condensation
Anode Maintenance
To inspect or change an anode:
Tank Flushing
Relief Valve Check
Vent Maintenance
Burner Maintenance

VII) COMBO HEATING . . . . . . . . . . . . . . . . . . . . . . . . 31

System Requirements 31
Installation 32

Fan Coil
Baseboard Radiator Heating

Maintenance 32

VIII) TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . 33

SUPERFLUE

TM

33

White-Rodgers Intelli-Vent

TM

35

INSTALLATION RECORD . . . . . . . . . . . . . . . . . . 36

LIMITED WARRANTY. . . . . . . . . . . . . . . . . . . . . . 37

RETAIN THESE INSTRUCTIONS IN A SAFE LOCATION FOR FUTURE REFERENCE

– 4 –

Replacement Parts Listing/Clearance to Combustibles

1. TERMINATION ELBOW WITH RODENT SCREEN

2. PIPE LENGTH *

3. PIPE COUPLING *

4. PIPE ELBOW *

5. RUBBER COUPLING

6. AIR TUBING

7. AIR SWITCH

8. JUNCTION BOX

9. JUNCTION BOX COVER

10. POWER CORD

11. BLOWER

12. BLOWER SUPPORT BRACKET

13. DRAFT DIVERTER

14. HIGH LIMIT SWITCH

15. ANODE (UNDER CAP)

16. INLET NIPPLE

17. DIPTUBE

18. T&P VALVE

19. DRIPTUBE *

20. BAFFLE ASSEMBLY

21. CONTROL VALVE (WHC)

22. CONTROL VALVE COVER (WHC)

23. INNER GAS DOOR

24. OUTER GAS DOOR

25. DRAIN VALVE

26. FLARE TUBE (GAS SUPPLY)

27. IGNITER ASSEMBLY

28. FLAME SENSOR

29. IGNITER BRACKET

30. ORIFICE

31. AIR SHUTTER

32. CAST IRON BURNER

33.

34. HEATING SYSTEM SUPPLY

35. HEATING SYSTEM RETURN

36. PVC ADAPTER

* OWNER SUPPLIED

Note: Manifold Tube Connections at Control Valve;

Right-Hand Threads for Natural Gas,
Left-Hand Threads for Propane

10

11

12

20

34

21 22

23 24

MINIMUM
CLEARANCE
50mm (2 in.)

DRAIN PAN IF REQUIRED
MIN. DIA. 660mm (26 in.)

MAX. PAN DEPTH
45mm (1 3/4 in.)

25

FLOOR DRAIN

MINIMUM
CLEARANCE
25mm (1 in.)

19

MINIMUM
CLEARANCE
25mm (1 in.)

18

17

16

14

15

MINIMUM
CLEARANCE
300mm (12 in.)

13

5

4

3

2

6

7

9

8

35

36

CAST IRON BURNER ASSEMBLY USED
WITH THE INTELLI-VENT

TM

GAS VALVE.

Figure 1 Water Heater and Burner Assemblies

1

30

28

32

27

29

31

26

26

27

28

29

32

30

31

CAST IRON BURNER ASSEMBLY USED
WITH THE 2000N WDER GAS VALVE.

– 5 –

Your safety and the safety of others is very important.

We have provided many important safety messages in this manual and on your appliance.
Always read and obey all safety messages.

All safety messages will tell you what the potential hazard is, tell you how to reduce the
chance of injury, and tell you what can happen if the instructions are not followed.

This is the safety alert symbol.
This symbol alerts you to potential hazards that can kill or hurt you and others.
All safety messages will follow the safety alert symbol and either the word
“DANGER” or “WARNING”.

DANGER

WARNING

You can be killed or seriously injured if you don’t immediately follow
instructions.

You can be killed or seriously injured if you don’t follow instructions.

I) INTRODUCTION

We thank you for choosing a GSW/John Wood Water
Heater. Your satisfaction with this product is very important

to us. This gas-fired water heater has been developed to
produce potable hot water and may also be used in combi­nation with space heating applications. The “Superflue”™
series is designed to vent the products of combustion (flue
gases) horizontally through an exterior wall or vertically
through the roof using an integrated blower assembly and
plastic piping, without the need for a conventional chimney.

User Responsibilities

This manual has been prepared to acquaint you with the
installation, operation and maintenance of your gas fired
water heater and provide important safety information in
these areas. It is your responsibility to ensure that your
water heater is properly installed and cared for.

FAILURE TO FOLLOW THE INSTRUCTIONS IN THIS
MANUAL MAY RESULT IN SERIOUS BODILY INJURY
AND/OR PROPERTY DAMAGE. THOROUGHLY READ
AND UNDERSTAND ALL INSTRUCTIONS BEFORE YOU
ATTEMPT TO INSTALL, OPERATE OR MAINTAIN THIS
HEATER.

Installation and service requires trade knowledge in the
areas of plumbing, electricity, venting, air supply and gas
supply. If you lack these skills or have difficulty understand­ing these instructions, you should not proceed. Enlist the
help of a qualified service technician to install this water
heater.
Examples of qualified service technicians include those
trained in the plumbing and heating industry, local gas utili­ty personnel or an authorized service person.

Service to the Power Vent System should only be per­formed by a qualified service technician.

The manufacturer and seller of this water heater will not
assume any liability for any property damage, personal
injury or death resulting from improper sizing, installation or
failure to comply with these instructions.

The warranty on this water heater is in effect only when the
water heater is installed and operated in accordance with
these instructions. A data plate identifying your water heater
can be found above the gas control/thermostat. When refer­ring to your water heater, always have the information listed
on the data plate readily available.

Protect your warranty: Regularly service your water
heater as directed in the "Maintenance" section of this man­ual.
Retain your original receipt as proof of purchase.

Do not discard this manual. You or future users of this
water heater will need it for reference.

II) SAFETY

This water heater is design-certified by CSA International as
a Category III, non-direct vented water heater that takes its
combustion air either from the installation area or from air
ducted to the unit from the outside.

In addition to the installation instructions found in this man­ual, the water heater must be installed in accordance with
all local and provincial or state codes or, in the absence of
such, with the latest editions of the following specifications.

For Installations in Canada:

"Natural Gas and Propane Installation Code" CAN/CSA­B149.1 and "Canadian Electrical Code” (CAN/CSA
C22.1), Part I available from:

Canadian Standards Association,
5060 Spectrum Way,
Mississauga, Ontario, Canada
L4W 5N6

For Installations in the United States:

"National Fuel Gas Code" ANSI Z223.1 (NFPA 54) and
"National Electrical Code" (NFPA 70) available from:

American National Standards Institute,
25 West 43rd Street,
New York, NY 10036
Massachusetts code requires this water heater to be
installed in accordance with Massachusetts Plumbing and
Fuel Gas Code 248 CMR Section 2.00 and 5.00.

Check your phone listings for the local authorities having
jurisdiction over your installation.

Safety Warning (Flammable Vapours)

There is a risk of property damage, personal injury or death
from the by-products of combustion (e.g., flue gases), in
using fuel-burning appliances such as water heaters. Areas
that may not be suitable for water heater installation include
those where flammable liquids, gasoline, solvents, adhe­sives etc. are stored, or where engine-driven equipment or
vehicles are stored, operated or repaired. These, and simi-

lar products, should not be stored or used near the water
heater or air intake. Due to the nature of air movement,
flammable vapours can be carried some distance from the
point of storage. The gas-fired water heater igniter or burn­er flame can ignite these vapours causing a flashback, fire
or explosion, which may result in severe property damage,
serious personal injury or death. If flammable liquids or
vapours have spilled or leaked in the area of the water
heater, leave the area immediately and call the fire depart­ment from a neighbor's home. Do not attempt to clean the
spill until all ignition sources have been extinguished.

Safety Warning (Scalding)

Hot water produced by this appliance can cause severe
burns due to scalding. The hazard is increased for young
children, the aged or the disabled when water temperatures
exceed 52°C (125°F). Use tempering valves, also known as
mixing valves, in the hot-water system to reduce the risk of
scalding at point-of-use such as lavatories, sinks and
bathing facilities (see Figure 16). Such precautions must be
followed when this heater is operated in combination with
dishwashing or space heating applications.

Safety Warning (Carbon Monoxide)

As with all fuel burning equipment, this heater requires an
adequate supply of air for combustion and ventilation. An
insufficient air supply can result in poor combustion or the
re-circulation of the flue gases. Such a condition can cause
soot build-up and present a fire hazard. Flow reversal of flue
gases can cause an increase of carbon monoxide inside of
the dwelling that could result in serious bodily harm or death
from asphyxiation.

MAKE SURE THE FLOW OF COMBUSTION AND
VENTILATION AIR IS NOT RESTRICTED.

WARNING

Flammable Vapours

FLAMMABLES

FIRE AND EXPLOSION HAZARD

Can result in serious injury or death

Do not store or use gasoline or other flammable vapours and liquids
in the vicinity of this or any other appliance. Storage of or use of gasoline
or other flammable vapours or liquids in the vicinity of this or any other
appliance can result in serious injury or death.

DANGER

DANGER

Carbon Monoxide Warning

• Follow all vent system requirements by
the local authorities having jurisdiction
over your installation.

• Failure to do so can result in death, explo­sion or carbon monoxide poisoning.

– 6 –

Relief Valve Requirements (T&P)

All water heaters must be fitted with a proper temperature
and pressure relief valve. These valves must be certified as
meeting the requirements of the "Standard For Relief

Valves For Hot Water Supply Systems”, ANSI
Z21.22/CSA 4.4.

If this water heater has been exposed to flooding, freezing,
fire or any unusual condition, do not put it into operation until
it has been inspected and approved by a qualified service
technician. THESE CONDITIONS CAN RESULT IN
UNSEEN INTERNAL DAMAGE and are not subject to war­ranty coverage.

III) INSTALLATION

Unpacking the Water Heater

Important: Do not remove any permanent instructions,
labels, or the data label from outside of the water heater or
on the inside of panels.

•

Remove exterior packaging and place installation com­ponents aside.

•

Inspect all parts for damage prior to installation and
start-up.

•

Completely read all instructions before attempting to

assemble and install this product.
If you observe damage to the water heater or any of its com­ponents, DO NOT ASSEMBLE OR INSTALL IT OR MAKE
ANY ATTEMPT TO FIX THE DAMAGED PART(S). Contact
the place of purchase for further instructions.

•

After installation, dispose of packaging material in the

proper manner.

Location Requirements

The water heater must be installed indoors in an area not
subject to freezing temperatures and in a vertical position
on a level surface. Water heaters located in unconditioned
spaces (e.g., attics, basements etc.) may require insulation
of the water piping, drain piping and venting to protect
against condensation. The power vented series of water
heaters are designed to vent the products of combustion
horizontally through the wall or vertically through the roof.
The blower expels the products of combustion by means of
plastic piping to the outdoors without the need for a con­ventional chimney.
Select a location as centralized within the piping system as
possible. The heater should be located in an area where
leakage of the tank or connections will not result in damage
to the area adjacent to the water heater or to lower floors of
the structure (see "IMPORTANT" notice above). Before
installing this water heater, consideration and planning must
be given to the following details:

•

Proximity to walls and other objects (see "Clearance
and Accessibility").

•

Air supply (see “Air Requirements”).

•

Access to gas supply (see "Gas Supply").

•

Routing and support of the vent piping and termination
(see "Exhaust Venting").

•

Position of water supply and placement of water piping
and floor drain (see "Water Supply").

In Earthquake Zones

Note: The water heater must be braced, anchored, or
strapped to avoid moving during an earthquake. Contact
local utilities for code requirements in your area.

IMPORTANT:

This water heater must be installed strictly in accordance
with the instructions enclosed, and local electrical, fuel
and building codes. It is possible that connections to the
water heater, or the water heater itself, may develop
leaks. IT IS THEREFORE IMPERATIVE that the water
heater be installed so that any leakage of the tank or relat­ed water piping is directed to an adequate drain in such a
manner that it cannot damage the building, furniture, floor
covering, adjacent areas, lower floors of the structure or
other property subject to water damage. This is particular­ly important if the water heater is installed in a multi-story
building, on finished flooring or carpeted surfaces. GSW
WILL NOT ASSUME ANY LIABILITY for damage caused
by water leaking from the water heater, pressure relief
valve, or related fittings. Select a location as centralized
within the piping system as possible. In any location
selected, it is recommended that a suitable drain pan be
installed under the water heater. This pan must limit the
water level to a MAXIMUM depth of 45mm (1 3/4 in.) and
have a diameter that is a minimum of 50mm (2 in.) greater
than the diameter of the water heater. Suitable piping shall
connect the drain pan to a properly operating floor drain.
When used with a fuel-fired heater, this drain pan must not
restrict combustion air flow.

WARNING

Excessive Weight Hazard

Use two or more people to move and install
water heater. Failure to do so can result in
back or other injury.

CAUTION

Hydrogen gas can be produced in a hot water system
served by this heater that has not been used for a long
period of time (generally two (2) weeks or more).

Hydrogen gas is extremely flammable and can ignite
when exposed to a spark or flame. To reduce the risk of

injury under these conditions, it is recommended that the
hot water faucet be opened for several minutes at the
kitchen sink before using any electrical appliance con­nected to the hot water system. Use caution in opening
faucets. If hydrogen is present, there will probably be an
unusual sound such as air escaping through the pipe as
the water begins to flow. There should be no smoking or
open flame near the faucet at the time it is open.

– 7 –

Note: The water heater may be installed in a closet with a
door off a bedroom or bathroom providing the units are
installed and vented per the manufacturer's instructions.
Important: If installing over carpeting, the carpeting must
be protected by a metal or wood panel beneath the water
heater. The protective panel must extend beyond the full
width and depth of the water heater by at least 76mm (3 in.)
in each direction or if in an alcove or closet installation, the
entire floor must be covered by the panel.

Clearances and Accessibility

•

The minimum clearances between the heater and com-

bustible materials are:

Top 300mm (12 in.)
Front 100mm (4 in.)

Rear and Sides 25mm (1 in.)
Note: These requirements are also listed on the data plate
located on the front of the water heater.

•

The water heater is certified for installation on a com-

bustible floor.
Figure 2 may be used as a reference guide to locate the
specific clearance locations. A minimum of 600mm (24 in.)
of front clearance and 100mm (4 in.) on each side should be
provided for inspection and service.

Gas Supply

Read the data plate to be sure the water heater is made
for the type of gas you will be using in your home. This

information will be found on the data plate located above the
gas control valve. If the information does not agree with the
type of gas available, do not install or attempt to start. Call
your dealer.

Note: An odourant is added by the gas supplier to the gas
used by this water heater. This odourant may fade over an
extended period of time. Do not depend upon this odourant
as an indication of leaking gas.

This gas 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.).

Use properly sized gas piping and to ensure full gas input
and a properly sized gas supply regulator to ensure ade-

DANGER

Explosion Hazard

• Use a new CSA approved gas supply line.

• Install a gas supply shut-off valve.

• Do not connect a natural gas water heater
to a L.P. gas supply.

• Do not connect a L.P. gas water heater to
a natural gas supply

• Failure to follow these instructions can
result in death, an explosion or carbon
monoxide poisoning.

GROUND-JOINT
UNION

MANUAL

GAS

SHUT-OFF

SEDIMENT
TRAP

GAS
VALV E

GAS
MANIFOLD

76mm (3 in.)

Figure 3 Gas Piping

– 8 –

Figure 2 Rough-in Dimensions

“G”

COLD INLET
3/4” NPT

HOT OUTLET

3/4” NPT

HEATING

OUTLET

HEATING

INLET

POWER CORD

(120) VAC/60Hz

GAS INLET

1/2” NPT

DRAIN
VALV E

T&P

VALV E

“A”

“I”

“B”

“E”

“D”

“F”

“C”

“H”

ABCD E FGH I

mm

610 302 432 1388 1575 1826 76 305 537

in. 24 11- 7/8 17 54-5/8 62 71-7/8 3 12 21-1/8

G/JW75

M ODEL NO.

quate gas supply pressure. The supply piping and regulator
must be large enough to satisfy the requirements of all
appliances connected to the gas service and when all appli­ances are operating simultaneously. Undersize piping and
insufficient pressure can restrict the gas flow causing the
water heater to perform poorly. Improperly sized piping may
pose a safety hazard.

Note: When installing gas piping, apply sealing compounds
approved for use with natural and propane gas.

1. Install a readily accessible manual shut-off valve in the
gas supply line as recommended by the local utility. The
owner/operator must be shown the location of this valve
and be given instructions on how to use it to shut off the
gas to the heater.

2. Install a drip leg (if not already incorporated as part of
the water heater) as shown. The drip leg must be no
less than 76mm (3 in.) long for the accumulation of dirt,
foreign material, and water droplets.

3. Install a ground joint union between the gas control
/thermostat and the manual shut-off valve. This is to
allow easy removal of the gas control/thermostat.

4. Turn the gas supply on and check for leaks. Use a chlo­ride-free soap and water solution (bubbles forming indi­cate a leak) or other approved method.

Gas Supply Pressure

Important: The gas supply pressure must not exceed the
maximum supply pressure as stated on the water heater's
data plate.

Gas line purging

Air may be present in the gas lines and could prevent the
burner from lighting on initial start-up. The gas lines should
be purged of air by a qualified service technician after instal­lation of the gas piping system.

Gas Leak Testing

Important: This water heater and its gas connection must
be leak tested before placing the appliance in operation.

•

If the code requires the gas lines to be tested at a pres­sure exceeding 14 in. w.c. (3.5 kPa), the water heater
and its manual shut-off valve must be disconnected
from the gas supply piping system and the line capped.

•

If the gas lines are to be tested at a pressure less than
14 in. w.c. (3.5 kPa), the water heater must be isolated
from the gas supply piping system by closing its manu­al shut-off valve.

Gas Operating Pressures

The gas supply pressure and burner manifold pressure is
listed on the data plate located on the front of the heater
above the gas control/thermostat. Ensure the gas supply
pressure to the water heater and the burner manifold pres­sure are properly adjusted while all appliances are in oper­ation. Refer to Figure 20 for Gas Control/Thermostat
Details.

U.L. and CSA recognized fuel gas and Carbon Monoxide
(CO) detectors are recommended in all applications and
should be installed using the manufacturer's instructions
and local codes, rules or regulations.

Air Requirements

General

•

An adequate air supply shall be provided for combus­tion and ventilation of this water heater. An insufficient
supply can result in poor combustion and possible soot­ing of the burner, combustion chamber or flue passage­way. This may present a potential fire hazard or could
create a serious health hazard by producing carbon

monoxide.
Where an exhaust fan or any other air consuming appliance
(e.g., clothes dryer, furnace, etc.) is installed in the same
space as the water heater, sufficient air openings must be
available to provide fresh air when all appliances are oper­ating simultaneously.

For buildings that are not well-sealed (do not have tight fit­ting doors and windows) natural air infiltration may provide
sufficient air required for combustion and ventilation. For
buildings using tight construction (newer and renovated
structures), the air supply shall be introduced from the out­doors, regardless of whether the space is confined or
unconfined.

Combustion Air “Supply” Ducts

Air supply ducts shall be of galvanized steel or equivalent
corrosion resistant material. A single air duct may not be
substituted when required for upper and lower air openings.
Horizontal combustion air ducts shall not slope downward
toward the air inlet.

Louvers and Grilles

Openings for air supply ducts must provide free unobstruct­ed air movement. Louver and grille openings must be sized
to ensure that the FREE OPEN AREA is never less than the
area of the air duct.

– 9 –

WARNING

Exposure to a higher gas supply pressure
may cause damage to the control, resulting
in explosion or fire. Consult your local gas
supplier and gas authorities. DO NOT PUT
INTO SERVICE IF OVER-PRESSURIZATION
HAS OCCURRED.

WARNING

Failure to properly install this heater may
result in a fire hazard.

Air Requirements

Important: Air for combustion and ventilation must not
come from a corrosive atmosphere. Any failure due to cor­rosive elements in the atmosphere is excluded from war­ranty coverage.
Installations in or for certain places including, but not limited
to, those listed below will require outdoor air for combustion
to reduce the risk of chemical exposure:

Beauty shops
Photo processing labs
Buildings with indoor pools
Water heaters installed in laundry, hobby or craft rooms
Water heaters installed near chemical storage areas

In such circumstances, outdoor combustion air may reduce,
but will not eliminate the presence of corrosive chemicals in
the air. Combustion air must be free of acid-forming chemi­cals such as sulfur, fluorine and chlorine. These elements
are found in aerosol sprays, detergents, bleaches, cleaning
solvents, air fresheners, paint and varnish removers, refrig­erants and many other commercial and household prod­ucts. When burned, vapours from these products form high­ly corrosive acid compounds. These products should not be
stored or used near the water heater or air inlet.

The area in which the heater is located is classified as either
"an unconfined sp

ace

" or "a confined sp

ace

."

An unconfined sp

ace is defined as a space having a vol­ume not less than 50 cubic feet per 1000 BTU/hour (4.8
cubic metres per kilowatt) of combined input rating of all
appliances using the space. Adjacent open rooms may be
included as part of the unconfined space, provided there
are no closeable doors between these rooms. An exam­ple of this is an open basement.

A confined sp

ace is one smaller than described above.
For buildings using tight construction (newer and renovated
structures), the air supply shall be introduced from the out­doors, regardless of whether the space is confined or
unconfined.

Confined Space Air Requirements for
Canadian Installations

Refer to Figure 4 (a), or (b), and Table 1 for proper sizing
and location of combustion air ducts and openings. CHECK
LOCAL CODES.
a). Two permanent openings shall be provided connecting

the confined space (e.g., closet, small room) with the
unconfined space. Each opening shall have a free area
of one square inch per 1,000 BTU/hour input (22
cm²/kW) of all appliances in the confined space. The top
opening shall be located as close to the ceiling as prac­tical but never lower than the top of the heater. (see
Figure 4 (a)). The bottom opening shall be located nei­ther more than 450mm (18 in.), nor less than 150mm (6

in.), above floor level.
Note: Ensure sufficient ventilation air to prevent elevated
temperatures in closets and confined spaces.

b). When using a single air supply, the duct shall terminate

within 300mm (12 in.) above and within 600mm (24 in.)
horizontally of the burner level

of the appliance having
the largest input. For example: GSW's water heaters'
burners are 150mm (6 in.) from the floor, plus 300mm
(12 in.) equals 450mm (18 in.) as shown in Figure 4 (b).
All exterior vent openings are to be at least 300mm (12
in.) above the ground and clear of snow levels.

– 10 –

CONFINED

SPACE

PERMANENT
OPENINGS

EQUIPMENT LOCATED IN CONFINED SPACES;

ALL AIR FROM INSIDE THE BUILDING.

(a)

UNCONFINED
SPACE

BASEMENT INSTALLATION, EQUIPMENT LOCATED

IN CONFINED SPACES; ALL AIR FROM OUTDOORS

(b)

CONFINED

SPACE

GRADE

COMBINATION
COMBUSTION/

VENTILATION

AIR DUCT

300mm
(12 in.)
(MIN)

450mm (18 in.)

600mm (24 in.)

Figure 4 Combustion Air Supply Openings And Ducts

(Canada)

BTU / h (kW / hr)

cm2in.2mm in. mm in.

75,000 23 70 11 100 4 125 5
100,000 30 90 14 100 4 125 5
125,000 37 120 18 125 5 150 6
150,000 45 140 22 125 5 150 6

Acceptable Round

Duct Size Diameter

Combined Input of

All Appliances in

Confined Space*

Required

Free Area

A**

B***

Table 1 Air Supply Sizing (Canada)

* All appliances refers to, and includes, those appliances

using the same air source (e.g. water heater, furnace,
boiler, clothes dryer etc.).

** Maximum allowable length of ductwork listed in column

A is 6.1 equivalent metres (20 ft.).

*** Maximum allowable length of ductwork listed in column

B is 15.2 equivalent metres (50 ft.).

Confined Space Air Requirements for
U.S. Installations

Refer to Figure 5 (a), (b), (c) or (d) for proper sizing and
location of combustion air ducts and openings. CHECK

LOCAL CODES.

(a) Equipment located in confined spaces; all air from

inside the building.

Two permanent openings shall be provided connecting
the confined space (e.g., closet, small room) with the
unconfined space. Each opening shall have a free area
of one square inch per 1,000 BTU/hour input (22
cm²/kW) of all appliances in the confined space, but not
less than 100 square inches (645 cm²). The top open­ing shall commence within 300mm (12 in.) of the top of
space and the bottom opening shall commence within
300mm (12 in.) of the bottom of the enclosure.

(b) Basement installation, equipment located in con-

fined spaces; all air from outdoors.

When supplying air directly from the outdoors, each
opening shall have a minimum free area of one square
inch per 4,000 BTU/hour input (5.5 cm²/kW) of total
input rating of all appliances in the confined space. The
inlets shall be a minimum of 300mm (12 in.) above the
grade (snow) line. The top opening shall commence
within 300mm (12 in.) of the top of the confined space.

(c) Equipment located in confined spaces; all air from

outdoors.

When supplying air directly from the outdoors using hor­izontal ducting, each opening shall have a free mini­mum area of one square inch per 2,000 BTU/hour (11
cm²/kW) of total input rating of all appliances in the con­fined space.

(d) Equipment located in confined spaces; all air from

outdoors through ventilated attic.

When supplying air directly through vertical ducting,
each opening shall have a free minimum area of one
square inch per 4,000 BTU/hour (5.5 cm²/kW) of total
input rating of all appliances in the confined space.

Note: Ensure sufficient ventilation air to prevent elevated
temperatures in closets and confined spaces.

CONFINED

SPACE

PERMANENT
OPENINGS

EQUIPMENT LOCATED IN CONFINED SPACES;

ALL AIR FROM INSIDE THE BUILDING.

(a)

UNCONFINED
SPACE

CONFINED

SPACE

ATTIC LOUVERS TO OUTDOORS

EQUIPMENT LOCATED IN CONFINED SPACES; ALL AIR

FROM OUTDOORS THROUGH VENTILATED ATTIC.

(d)

INLET AIR
DUCT

OUTLET

AIR

BASEMENT INSTALLATION, EQUIPMENT LOCATED
IN CONFINED SPACES; ALL AIR FROM OUTDOORS

(b)

CONFINED

SPACE

GRADE

300mm

(12 in.)

300mm

(12 in.)

Figure 5 Combustion Air Supply Openings And Ducts

(U.S.A.)

COMBUSTION

AIR DUCT

PERMANENT

VENTILATION

AIR.

300mm

(12 in.)

ABOVE

GRADE

OR

SNOW

LINE

EQUIPMENT LOCATED IN CONFINED

SPACES; ALL AIR FROM OUTDOORS.

(c)

CONFINED

SPACE

COMBUSTION

300mm (12 in.)

300mm (12 in.)

300mm (12 in.)

OUTDOORS

AIR DUCT

VENTILATION

Burn Hazard
Do not touch vent.
Doing so can result in

burns.

– 11 –

Exhaust Venting

This heater is designed to exhaust the products of combus­tion (flue gases) to the outdoors using a sealed piping sys­tem. Table 2 lists the allowable vent materials and sizing
information. Figure 8 shows the general venting layout while
Figures 9-12 show various end termination details and
clearances. Connection of the venting piping to the blower
is shown in Figure 14.
Correct installation of the venting system is essential to the
safe and efficient operation of this water heater. Vent piping
must be installed in accordance with all applicable local and
provincial or state codes. In the absence of such codes, all
installation shall meet the requirements as stated in the lat­est edition of the "Natural Gas and Propane Installation

Codes" CAN/CSA-B149.1 (Canada) or "National Fuel
Gas Code" ANSI Z223.1 (NFPA 54) (U.S.A.).

Important Notes and Warnings

•

This heater is certified to be installed using Schedule 40
PVC or CPVC plastic vent material. In Canada some
jurisdictions require that this material be approved to
ULC S636. ULC S636 mandates that components from
different systems must not be mixed in the same vent
runs. Check local codes to determine which materials
are allowed in your area and only use approved materi­al. All venting material and components must be joined
with the approved primer/cleaner and solvent cement.

•

Do not common vent this heater with any other appli­ance.

•

During operation the plastic piping will expand as it
heats up and contract as it cools down. This is normal
for this type of venting. Rigidly fastening the vent piping
can cause undue stress that may result in the cracking
or fracturing the vent piping material. A fracture of the
venting pipe poses a serious safety hazard. To prevent
stressing of the vent system, all hangers and supports
must allow the vent piping freedom to move.

•

All power vented water heaters generate a certain
amount of operational noise. In order to minimize noise
transmission to the support structure, use isolation pads
between the pipe hangers and the vent pipe.

•

Most power vent installations develop some condensa­tion in the vent piping. When using long runs of venting
or when the venting passes through cold or unheated
areas, considerable amounts of condensate from the
flue gases can develop. Provision must be made for the
condensate to drain freely from the system or to be col­lected in a condensate trap(s) that can be drained.
Damage or fracture of the vent piping may occur if the
condensate is allowed to collect and freeze. Pooling of
condensate can restrict airflow and can cause nuisance
failures of the system.

•

Be aware of any concealed wiring or piping inside the
walls.

– 12 –

PREFERRED PRACTICE

150mm

(6 in.) min.

STREET ELBOW NORMAL ELBOW

BACK TO BACK ELBOWS

Figure 6 Correct Pipe Fittings

90° LONG SWEEP ELBOW

90° SHORT SWEEP ELBOW

VENT LENGTH LESS THAN OR

EQUAL TO 6.1 EQUIVALENT METRES

(20 FT.) USE PLASTIC SCREEN.

VENT LENGTH GREATER THAN 6.1
EQUIVALENT METRES (20 FT.) USE

STEEL MESH SCREEN.

Figure 7 Rodent Screens