A.O. Smith GPVT 40, GPVT 50, GPVL-40, GPVT-40 LP, GPVL-50 LP Technical Documents

Service Handbook

RESIDENTIAL GAS WATER HEATERS

POWER VENTED GAS MODELS

WITH HOT SURFACE IGNITION

NOT FOR USE IN MANUFACTURED (MOBILE) HOMES

TABLE OF CONTENTS

GENERAL INFORMATION 2
CHECKING THE GAS SUPPLY PRESSURE 3
LEAKAGE CHECKPOINTS 4
TEMPERATURE ADJUSTMENT 5
ANODE ROD REMOVAL/REPLACEMENT 6
DIP TUBE REMOVAL/REPLACEMENT 7
DOOR-BURNER ASSEMBLY REMOVAL/
REPLACEMENT 8
FLAME SENSOR AND IGNITER REMOVAL/
REPLACEMENT 10
BURNER AND ORIFICE REMOVAL/
REPLACEMENT 12
DOOR GASKET REPLACEMENT 16
CONTROL MODULE REMOVAL/REPLACEMENT 18
VALVE MODULE REMOVAL/REPLACEMENT 20
TEMPERATURE SENSOR AND CABLE REMOVAL/
REPLACEMENT 21
GAS VALVE REMOVAL/REPLACEMENT 22
BLOWER REMOVAL/REPLACEMENT 24
ROTATING THE BLOWER 25
PRESSURE SWITCH REMOVAL/REPLACEMENT 26
FV SENSOR 27
CLEANING THE COMBUSTION CHAMBER 28
CLEANING THE BLOWER 29
TECHNICAL BULLETINS 30
TROUBLESHOTING CHART 36

Note: References to the Manual refer to the “Installation
and Operating Manual”.

1206 322153-000 Rev. 00

GENERAL INFORMATION

Draw effi ciency is the quantity of hot water available to the

consumer before the outlet water temperature decreases
by 25F° (14C°). A 40 gallon water heater will typically
provide 70% (28 gallons) of this “usable” hot water (60%
is the minimum). The burner or elements are allowed to
operate during this test. Incoming, cold water mixes the
remaining stored water below this 25F° (14C°) limitation.

Energy Factor is an indicator of the combined thermal
effi ciency and standby effi ciency of a water heater. The
higher the energy factor, the more effi cient the water
heater will be.

Minerals and gases will separate from water as
temperature increases.

“R” Value is a measure of the resistance of a substance
to heat fl ow.

Recovery rate is the amount of water that is heated to a
set temperature, per hour.

Standby effi ciency is the water heater’s ability to contain
heat in the tank. A minimum of tank water heat loss per
hour is desired. e.g. temperature change/“R” value = Btu/h
loss/square foot of tank surface

Temperature rise is the increase in the temperature from
its coldest “inlet” water temperature to the desired hot
(outlet) setting. Typically it is assumed that the entering
water be 40°F (5°C), stored water desired to be 120°F
(49°C) resulting in a “temperature rise” of 80F° (44C°).

Thermal efficiency is approximately the amount of
generated BTU (British Thermal Units), which enters the
water. A percentage of the total BTU passes out through
the vent piping.

Water cannot (for all practical purposes) be
compressed.

Water expands when it is heated.

Formulas and Conversions:

BTU (British Thermal Unit) is the heat required to raise 1
pound of water 1F°
1 BTU = 252 cal = 0.252 kcal
1 cal = 4.187 Joules
BTU X 1.055 = Kilo Joules
BTU divided by 3,413 = Kilowatts
To convert from Fahrenheit to Centigrade: (°F – 32) times
5/9, or .556, equals degrees C.
One gallon of (120°F, 49°C) water weighs approximately

8.25 pounds.
Pounds X .45359 = Kilogram
Gallons X 3.7854 = Liters
% of Hot = (Mixed Temp. – Cold) divided by (Hot Temp.
– Cold)
% Thermal Effi ciency = (GPH X 8.25 X Temp. Rise X 1.0)
divided by BTU/H Input
BTU Output = GPH X 8.25 X Temp. Rise X 1.0
GPH = (BTU/H Input X % Eff.) divided by (Temp. Rise X

8.25)
One cubic foot of Natural Gas contains about 1000 BTU
of heat.
One “therm” is equal to 100,000 BTU
One cubic foot of Propane Gas contains about 2500 BTU
of heat.
One gallon of Propane gas contains about 91,250 BTU
of heat.
One pound of Propane gas contains about 21,600 BTU
of heat.
One pound of gas pressure is equal to 27.7 inches water
column pressure
Inches of Water Column X .036091 = PSI
Inches of Water Column X .073483 = Inches of Mercury
(Hg.)
Centimeters = Inches X 2.54
mm (millimeters) = Inches X 25.4
Meters = Inches X .0254
Doubling the diameter of a pipe will increase its fl ow
capacity (approximately) 5.3 times.

Construction: Tank is constructed of steel. The inside of the
tank is constructed of a glass lining bonded to the steel.
This prevents water to metal contact and rusting of the
tank. An anode rod will be installed within the tank. The
hex-head plug end of the anode is visible on the top of the
water heater. This metal rod offers secondary protection of
the tank against corrosion where the application of glass
is not possible (threaded tank openings). These areas will
have small areas of water to metal contact.

All water heaters will contain at least one thermostat (to
operate the heater) and one high limit (to prevent water
from overheating).

2

CHECKING THE GAS SUPPLY PRESSURE

Gas pressure checks are done with fl owing gas using a
gas pressure manometer capable of reading pressure in
inches of water column.
Supply gas pressure checks are measured before the gas
control valve and as close to the water heater as possible.
Manifold (main burner) gas pressure is measured at the
pressure tap on the bottom of the gas control valve (see
Figure 1). Use an allen wrench to remove the plug, then
attach the gas gauge.

Note: Desired gas pressures will be noted on the gas valve
label located on the gas control valve and rating plate.

IF THEN

Supply gas pressure
is under desired
pressure requirement

Supply gas pressure
is over desired
pressure

Manifold gas pressure
is more than +/- .4
inch W.C. from values
indicated on gas valve
or rating plate

Increase supply gas

•

pressure regulator setting.
Call the gas utility company

•

to readjust gas pressure on
main supply. Technicians
can not adjust main gas
supply pressure.

Add gas pressure

•

regulator.
Call the gas utility company

•

to readjust gas pressure on
main supply. Technicians
can not adjust main gas
supply pressure.

Ensure there is adequate

•

supply gas pressure.
Ensure the main burner

•

orifice is the correct size
for the water heater model
being tested.
If the above tests have been

•

performed and the results
were correct replace the
gas control valve.

MANIFOLD (MAIN BURNER GAS PRESSURE

TAP). RE-INSTALL PLUG AFTER USE.

Figure 1

PRESSURE

MANOMETER

Important: After checking the manifold gas pressure,
detach the gas gauge, reinstall the plug using insulation
tape and tighten with allen wrench. Check for leaks and
repair as required.

3

LEAKAGE CHECKPOINTS

A. Water at the blower assembly is water vapor which

has condensed out of the combustion products. This
is caused by a problem in the vent or blockage in the
drain coupling.

B. Condensation may be seen on pipes in humid weather

or pipe connections may be leaking.
C. The anode rod fi tting may be leaking.
D. Small amounts of water from temperature-pressure

relief valve may be due to thermal expansion or high

water pressure in your area.
E. *The temperature-pressure relief valve may be leaking

at the tank fi tting.
F. Water from a drain valve may be due to the valve being

slightly opened.
G. The drain valve may be leaking at the tank fi tting.
H. Combustion products contain water vapor which can

condense on the cooler surfaces of the tank. Droplets

form and drip onto the burner. This is common at the

time of start-up after installation and when incoming

water is cold.
I. Water in the water heater bottom or on the fl oor may be

from condensation. DO NOT replace the water heater

until a full inspection of all possible water sources is

made and necessary corrective steps taken.
J. Leakage from other appliances, water lines, or ground

seepage should also be checked.

A

B

C

E

H

G

D

F

I

* To check where threaded portion enters tank, insert

cotton swab between jacket opening and fi tting. If cotton

is wet, follow draining instructions in the “Draining

and Flushing” section in the Manual and then remove

fi tting. Put pipe dope or Tefl on® tape on the threads

and replace. When you are fi nished, follow the steps

in “Filling the Water Heater” section in the Manual.

Figure 2

4

TEMPERATURE ADJUSTMENT

Safety
Due to the nature of the typical gas water heater, the
water temperature in certain situations may vary up to
30F° (16C°) higher or lower at the point of use such as
bathtubs, showers, sink, etc.

HOT WATER CAN SCALD: Water heaters are intended to
produce hot water. Water heated to a temperature which
will satisfy space heating, clothes washing, dish washing,
and other sanitizing needs can scald and permanently
injure you upon contact. Some people are more likely to
be permanently injured by hot water than others. These
include the elderly, children, the infi rm, or physically/
mentally handicapped. If anyone using hot water in your
home fi ts into one of these groups or if there is a local code
or state law requiring certain temperature water at the hot
water tap, then you must take special precautions.

In addition of using the lowest possible temperature setting
that satisfi es your hot water needs, a means such as a
mixing valve should be used at the hot water taps used
by these people or at the water heater. Mixing valves are
available at plumbing supply or hardware stores. Follow
manufacturer’s instructions for installation of the valves.
Using the lowest hot water temperature that meets your
needs will also provide the most energy effi cient operation
of the water heater.

Never allow small children to use a hot water tap, or to draw
their own bath water. Never leave a child or handicapped
person unattended in a bathtub or shower.

Note: A water temperature range of 120°F-140°F
(49°C-60°C) is recommended by most dishwasher
manufacturers.

Settings
Temperature range on residential gas water heater is from
110°F ±10° to 155°F ±10° and a 70°F vacation setting. The
T&P valve will open at 195°F ± 10°.
The water heater temperature adjusting dial (see Figure

3) was factory set at the lowest temperature; all the way
counter-clockwise to the mechanical stop, unless specifi ed
differently by provincial or state regulations. It is adjustable
and must be reset to the desired temperature setting to
reduce the risk of scald injury. Turning the dial clockwise
will increase the temperature and counter-clockwise
will reduce the temperature. The HOT marking on the
Honeywell gas valve is indicative of approximately 120°F
(49°C) and is the preferred starting point. Some states
have a requirement for a lower setting. Should overheating
occur or the gas supply fails to shut off, turn “OFF” the
manual gas control valve to the water heater.

temperatures at the point of use to exceed the thermostat
setting by up to 30F° (16C°). If you experience this type of
use, you should consider using lower temperature settings
to reduce scald hazards. Listed below is time-to-burn
relationship for normal adult skin.

Figure 3

Temperature

Setting

VERY HOT 155 (68) Less than 1 second

C 150 (65) About 1.5 seconds

B 140 (60) Less than 5 seconds

A 130 (54) More than 30 seconds

HOT 120 (49) More than 5 minutes

LOW 110 (43) Normal shower temp

VAC 70 (21) N/A

Approximate
Temperature

°F (°C)

Table 1

Time to reduce a 2nd

and 3rd Degree burn

to adult skin

The following table lists the approximate water temperatures
produced by various dial settings. Short repeated heating
cycles caused by small hot water uses can cause

5

ANODE ROD REMOVAL/REPLACEMENT

ANODE ROD

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

Ratchet with 1-1/16” Socket

•

Pliers

®

•

Te fl on

Tape or an approved pipe sealant

Removing Anode Rod:

Set the gas control valve/thermostat to its lowest

1.

setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).
Turn gas control switch to the “OFF” position and turn

2.

“OFF” the gas supply to the unit (see Figure 3).
Disconnect the electrical power to the water heater

3.

from the wall outlet.
Shut off the incoming water supply to the water heater

4.

and open a nearby hot-water faucet to depressurize
the water tank.
Connect a hose to the drain valve and terminate it to

5.

adequate drain or to the exterior of the building. Open
the drain valve and allow at least 5 gallons of water to
drain from the tank. Close drain and remove hose.
Remove and retain the anode cap on top of the heater

6.

and remove and retain just enough insulation so you
can access to the anode head (see Figure 4). Keep in
a safe place for reinstallation later.
Remove the anode rod by using a ratchet and a 1-1/16”

7.

socket turning counter-clockwise (see Figure 4).

Installing Anode Rod:

1.

Use Tefl on

®

tape or an approved pipe sealant on

threads of the new anode rod.

2.

Place the anode rod in the spud (top of the tank) and
turn clockwise until the threads are hand tight. Using a
ratchet and 1-1/16” socket tighten down water tight.

3.

Turn the main water supply back on.

4.

Open a nearby hot-water faucet to purge air from the
water line. Fill water heater tank completely (Note: To
assure the water heater tank is full, keep the hot-water
faucet open for 3 minutes after a constant fl ow of water
is obtained).

5.

After turning off the hot-water faucet, check for water
leaks around anode rod and immediately correct any
if found.

6.

Reinstall the insulation and anode cap which were
removed in step 6 above.

7.

Reconnect the electrical power to the water heater in
the wall outlet and turn the main gas supply back “ON”
to the gas control valve/thermostat.

8.

Turn the gas control switch to the “ON” position (see
Figure 3).

9.

To restart the water heater, follow the directions on
the “Lighting and Operating Instructions” label located
on the front of the water heater near the gas control
valve/thermostat.

CAP

* THE ANODE ROD IS COVERED
BY URETHANE FOAM LOCATED

UNDER THE CAP. CHIP AWAY

THE FOAM TO EXPOSE THE

TOP OF THE ANODE ROD

Figure 4

ANODE ROD *

6

DIP TUBE REMOVAL/REPLACEMENT

DIP TUBE

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

18” Pipe wrench

•

Piping and soldering equipment

®

•

Te fl on

Removing Dip Tube:

1.

2.

3.

4.

5.

6.

7.

Tape or an approved pipe sealant

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).
Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).
Disconnect the electrical power to the water heater
from the wall outlet.
Shut off the incoming water supply to the water heater
and open a nearby hot-water faucet to depressurize
the water tank. Remove pipe insulation from cold inlet
piping.
Connect a hose to the drain valve and terminate it to
adequate drain or to the exterior of the building. Open
the drain valve and allow at least 5 gallons of water to
drain from the tank. Close drain and remove hose.
Remove the inlet water piping connected to the cold
inlet of the water heater (see Figures 5 & 6). Some
installations will have a union connection, others will
have the supply piping soldered to an adapter that
connects to the nipple on the water heater. Using the
pipe wrench remove the piping from the top of the
tank.
With the piping removed, use the pipe wrench on the
exposed nipple directly to remove it from the heater.
Note: Sometimes the dip tube will come out with the
piping in one piece. Separate accordingly.

6.

After turning off the hot-water faucet, check for water
leaks around dip tube and immediately correct any if
found.

7.

Reinstall the pipe insulation removed in step 4 removal
process.

8.

Reconnect the electrical power to the water heater in
the wall outlet and turn the gas supply back “ON” to
the gas control valve/thermostat.

9.

Turn the gas control switch to the “ON” position (see
Figure 3).

10.

To restart the water heater, follow the directions on
the “Lighting and Operating Instructions” label located
on the front of the water heater near the gas control
valve/thermostat.

NIPPLE/DIP

TUBE

Figure 5

Installing Dip Tube:

Use Tefl on® tape or an approved pipe sealant on

1.
threads of the new dip tube.
Place the dip tube into the spud on top of the tank

2.

HOT-WATER

OUTLET

UNION

SHUT-OFF VALVE

UNION

COLD-

WATER

INLET

and turn clockwise until tight. Using the pipe wrench
continue to tighten until the joint is water tight. Note:
Do not clamp the pipe wrench jaws on the threaded
portion of the nipple and do not over tighten. This can
cause the threads to distort and can result in a leak.
Apply Tefl on® tape or pipe sealant on the top threads

3.
and reconnect the water piping (see Figure 6).
Turn the main water supply back on.

4.
Open a nearby hot-water faucet to purge air from the

5.
water line. Fill water heater tank completely (Note: To
assure the water heater tank is full, keep the hot-water

3/4” SWEAT

FITTING

BLOWER

ASSEMBLY

COMPONENTS

NOT SHOWN

FOR CLARITY.

3/4” SWEAT

FITTING

NIPPLE/DIP

TUBE

TEMPERATURE­PRESSURE
RELIEF VALVE

Figure 6

faucet open for 3 minutes after a constant fl ow of water
is obtained).

7

DOOR-BURNER ASSEMBLY REMOVAL/REPLACEMENT

INNER DOOR/MANIFOLD/BURNER ASSEMBLY

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

3/4” Open-End Wrench

•

Phillips Head Screwdriver

•

Ratchet with 1/4” socket or 1/4” nutdriver

•

Flashlight

Removing Inner Door/Manifold/Burner Assembly

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Remove the outer door from the unit.

5.

Unplug all the electrical connections from the bottom
of the gas control valve/thermostat (see Figure 7).

6.

Using a 3/4” open end wrench remove the manifold
tube from the gas control valve/thermostat (turning
counter-clockwise for natural gas, clockwise for L.P.).
Grasp the manifold tube and push down slightly to
free the manifold tube from the gas control valve/
thermostat (see Figure 7).

7.

Remove the insulation pad on the inner door by cutting
it if necessary. Keep the insulation in a safe place for
reusing it later.

8.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the 2 hex head screws on the inner door so the inner
door/manifold/burner assembly can be removed (see
Figure 7).

9.

Remove inner door/manifold/burner assembly by
grasping the manifold and pull back slowly. Rotating
it to the left to clear the igniter and fl ame sensor. Care
should be taken when inner door and burner assembly
passes through jacket opening that it does not damage
any of the electrical wiring (see Figure 9).

NOTE: OUTER DOOR AND INSULATION NOT SHOWN FOR CLARITY.

ELECTRICAL

CONNECTIONS

MANIFOLD
TUBE NUT

Figure 7

HEX HEAD

SCREWS

Caution Must Be Taken

Prior to installing the new inner door/manifold/burner, look
inside the burner chamber to fully understand the correct
positioning of the burner assembly and burner manifold
tab. It is necessary to use a fl ashlight to ensure correct
placement. Care must be taken so as to not damage any
electrical wiring or components as you are installing the
new inner door/manifold/burner assembly.
Extra caution should be taken to ensure that electrical
wiring, fi berglass insulation or any other object is not
between door gasket and combustion chamber shield.

Note: If the burner door gasket (see Figure 9) is worn
or damaged it needs to be replaced. See section “Door
Gasket Replacement”.

8

Re-installing Inner Door/Manifold/Burner Assembly

Insert the manifold/burner assembly in the

1.
burner chamber compartment, making sure
that the tip of burner manifold tab engages in
the proper slot of the bracket (see Figure 8).

Important:

• The tip end of the burner manifold MUST be placed
in the upper slotted portion for models with input rate
of 40,000 to 50,000 Btu/hr to obtain proper installation.

• The tip end of the burner manifold MUST be
placed in the lower slotted portion for models with
input rate of 60,000 to 75,000 Btu/hr to obtain proper
installation.
After confi rming no materials of any type are between

2.
door gasket and combustion chamber shield, align
the screws on the inner door with the screw holes
on the combustion chamber and tighten with 1/4”
nutdriver or 1/4” socket & ratchet (see Figure 7). After
tightening the inner door screws, visually inspect
area around door gasket and skirt for spaces or
gaps. The door gasket MUST be sealed completely
in order for the water heater to perform properly.
DO NOT OPERATE THE WATER HEATER IF THE
DOOR GASKET DOES NOT CREATE A SEAL
BETWEEN MANIFOLD DOOR AND COMBUSTION
CHAMBER.
Reconnect the manifold tube to the gas control valve/

3.
thermostat (Note: Do Not apply any thread sealant
at this connection). To prevent any cross threading
the manifold tube should be started by hand (turn
clockwise for natural gas, counter-clockwise for L.P.).
Upon tightening with the fi ngers and confi rming it has
not been cross threaded, tighten nut with a 3/4” open
end wrench (see Figure 7).
Reinstall the insulation pad which was removed in

4.
step 7 above.
Reconnect all the electrical connections to the bottom

5.
of the gas control valve/thermostat, gently pushing
each connector up until it snaps into place (see Figures
7 & 10).
Reconnect the electrical power to the water heater in

6.
the wall outlet and turn the main gas supply back “ON”
to the gas control valve/thermostat.
Restart the water heater by following the directions on

7.
the “Lighting and Operating Instructions” label located
on the front of the water heater. Test gas connections
by brushing on an approved non-corrosive leak
detection solution. (Note: Do not splash the solution
on control. If a leak is detected, shut the water heater
down by following the directions on the “Lighting and
Operating Instructions”. Repair the leak(s) and repeat
this step.
Upon verifying proper operation of the water heater,

8.
replace the insulation and outer door.

BURNER SUPPORT

BRACKET -

LOCATED IN THE

CENTRE OF THE

CHAMBER.

OUTER DOOR

ELECTRICAL

CONNECTIONS

STRAIGHT SLOT

FOR 40-50K

BURNERS WITH

STRAIGHT

MANIFOLD TUBES

Figure 8

INSULATION

PAD

Figure 9

CURVED SLOT FOR

60-75K BURNERS

MANIFOLD TUBES

GASKET ON

REAR OF DOOR

MOUNTING CLIP

(1 EACH SIDE)

WITH OFFSET

COMBUSTION

CHAMBER

OPENING

Figure 10

9

FLAME SENSOR AND IGNITER REMOVAL/REPLACEMENT

Remove and discard the old fl ame sensor and/or hot

FLAME SENSOR AND/OR HOT SURFACE IGNITER

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

3/4” Open-End Wrench

•

Phillips Head Screwdriver

•

Ratchet with 1/4” socket or 1/4” nutdriver

•

Flashlight

•

Flat Blade screwdriver

Removing Inner Door/Manifold/Burner Assembly:

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Remove the outer door from the unit.

5.

Unplug all the electrical connections from the bottom
of the gas control valve/thermostat (see Figure 11).

6.

Using a 3/4” open end wrench remove the manifold
tube from the gas control valve/thermostat (turning
counter-clockwise for natural gas, clockwise for L.P.).
Grasp the manifold tube and push down slightly to
free the manifold tube from the gas control valve/
thermostat (see Figure 11).

7.

Remove the insulation pad on the inner door by cutting
it if necessary. Keep the insulation in a safe place for
reusing it later.

8.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the 2 hex head screws on the inner door so the inner
door/manifold/burner assembly can be removed (see
Figure 11).

9.

Remove inner door/manifold/burner assembly by
grasping the manifold, rotating it to the left to clear the
igniter and fl ame sensor and pulling back. Care should
be taken when inner door and burner assembly passes
through jacket opening that it does not damage any
of the electrical wiring (see Figure 13).

Removing Flame Sensor And/Or Hot Surface Igniter:
Note: The confi guration of the fl ame sensor and igniter
allows you to replace them separately. It is recommended
to clean the fl ame sensor when you replace the igniter.

1.

Lift the retainer clip straight up from the back of
the manifold component block (using a fl at-blade
screwdriver), then remove the manifold component
block from the manifold door (see Figure 14).

2.

Disconnect the wiring connection between the fl ame
sensor/igniter and valve.

3.

Remove and retain the screw(s) securing the fl ame sensor
and/or hot surface igniter assembly (see Figure 14).

4.
surface igniter assembly.
Install the new Flame Sensor and/or Hot Surface

5.
Igniter.
Route the new fl ame sensor and/or hot surface igniter

6.
connector wire through manifold/burner door opening.
Secure the assembly to the bracket using screw(s)
removed in step 3 above.
Reconnect the wiring connection between the fl ame

7.
sensor/igniter and the valve.
Reposition the manifold component block in the

8.
manifold door opening and secure it with the retainer
clip.

Caution Must Be Taken

Prior to installing the new inner door/manifold/ burner
assembly, look inside the burner chamber to fully
understand the correct positioning of the burner assembly
and burner manifold tab. It may be necessary to use a
fl ashlight to ensure correct placement. Care must be taken
so as to not damage any electrical wiring or components
as you are installing the new inner door/manifold/burner
assembly.
Extra caution should be taken to ensure that electrical
wiring, fi berglass insulation or any other object is not
caught between door gasket and combustion chamber
shield.
Note: If the burner door gasket (see Figure 9) is worn
or damaged it needs to be replaced. See section “Door
Gasket Replacement”.
Re-installing Inner Door/Manifold/Burner Assembly

Insert the manifold/burner assembly in the burner

1.
chamber compartment, making sure that the tip of burner
manifold tab engages in the proper slot of the bracket
(see Figure 12). The tip end of the burner manifold MUST
be placed in the slotted portion under the condensation
pan to obtain proper installation (see Figure 12).

Important:

• The tip end of the burner manifold MUST be placed
in the upper slotted portion for models with input rate
of 40,000 to 50,000 Btu/hr to obtain proper installation.

• The tip end of the burner manifold MUST be
placed in the lower slotted portion for models with
input rate of 60,000 to 75,000 Btu/hr to obtain proper
installation.
After confi rming no materials of any type are between

2.
door gasket and combustion chamber shield, align
the screws on the inner door with the screw holes
on the combustion chamber and tighten with 1/4”
nutdriver or 1/4” socket & ratchet (see Figure 11).
After tightening the inner door screws, visually inspect
area around door gasket and skirt for spaces or
gaps. The door gasket MUST be sealed completely
in order for the water heater to perform properly.
DO NOT OPERATE THE WATER HEATER IF THE DOOR
GASKET DOES NOT CREATE A SEAL BETWEEN
MANIFOLD DOOR AND COMBUSTION CHAMBER.

10

Reconnect the manifold tube to the gas control valve/
thermostat (Note: Do Not apply any thread sealant
at this connection). To prevent any cross threading
the manifold tube should be started by hand (turn
clockwise for natural gas, counter-clockwise for L.P.).
Upon tightening with the fi ngers and confi rming it has
not been cross threaded, tighten nut with an 3/4” open
end wrench (see Figure 11).

3.

Reconnect all the electrical connections to the bottom
of the gas control valve/thermostat, gently pushing
each connector up until it snaps into place (see Figures
10 & 11).

4.

Reconnect the electrical power to the water heater in
the wall outlet and turn the main gas supply back “ON”
to the gas control valve/thermostat.

5.

Restart the water heater by following the directions on
the “Lighting and Operating Instructions” label located
on the front of the water heater.

6.

As the burner is heating (view flames through
viewport), test the manifold tube connection at
the gas control valve/thermostat by brushing on
an approved noncorrosive leak detection solution
(Important: Do Not splash the solution onto any
electrical connections. If a leak is detected, shut the
water heater down by following the directions on the
“Lighting and Operating Instructions”. Repair the
leak(s) and repeat step 6 above).

7.

Upon verifying proper operation of the water heater,
reinstall the insulation and the outer door.
Note: The structure of fl ame sensor/hot surface
igniter allows you to remove and replace them
separately.

BURNER SUPPORT

BRACKET -

LOCATED IN THE

CENTRE OF THE

CHAMBER.

OUTER DOOR

STRIGHT SLOT FOR

40-50K BURNERS

WITH STRAIGHT

MANIFOLD TUBES

Figure 12

INSULATION

PAD

GASKET ON

REAR OF DOOR

MOUNTING CLIP

(1 EACH SIDE)

Figure 13

CURVED SLOT FOR

60-75K BURNERS

WITH OFFSET

MANIFOLD TUBES

COMBUSTION

CHAMBER

OPENING

ELECTRICAL

CONNECTIONS

NOTE: OUTER DOOR AND INSULATION NOT SHOWN FOR CLARITY.

MANIFOLD
TUBE NUT

HEX HEAD

SCREWS

Figure 11

RETAINER

CLIP

COMPONENT

BLOCK

DRAIN

HOLE

IGNITER/
SENSOR

ASSEMBLY

Figure 14

11

BURNER AND ORIFICE REMOVAL/REPLACEMENT

BURNER

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

3/4” Open-End Wrench

•

Phillips Head Screwdriver

•

Ratchet with 1/4” socket or 1/4” nutdriver.

Removing Inner Door/Manifold/Burner Assembly:

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Remove the outer door from the unit.

5.

Unplug all the electrical connections from the bottom
of the gas control valve/thermostat (see Figure 15).

6.

Using a 3/4” open end wrench remove the manifold
tube from the gas control valve/thermostat (turning
counter-clockwise for natural gas, clockwise for L.P.).
Grasp the manifold tube and push down slightly to
free the manifold tube from the gas control valve/
thermostat (see Figure 15).

7.

Remove the insulation pad on the inner door by cutting
it if necessary. Keep the insulation in a safe place for
reusing it later.

8.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the 2 hex head screws on the inner door so the inner
door/manifold/burner assembly can be removed (see
Figure 15).

9.

Remove inner door/manifold/burner assembly by
grasping the manifold, rotating it to the left to clear the
igniter and fl ame sensor and pulling back. Care should
be taken when inner door and burner assembly passes
through jacket opening that it does not damage any
of the electrical wiring (see Figure 17).

Removing Burner:

1.

Burner may be hot. Wait until burner has cooled
off. After noting the position of the condensation
drain hole on the top of the burner, turn the inner
door/manifold/burner assembly upsidedown. Using
a Phillips head screwdriver, remove and retain the 2
screws attaching the burner to the manifold pipe (see
Figure 18 & 19).

Installing Burner:
Care MUST be taken to ensure the burner is installed
correctly on the inner door/manifold assembly. Position
the new burner upside down with the orientation of the
burner’s condensation drain as shown in illustration (see
Figure 18 & 19).

Align the screw holes on the inner door/manifold

1.
assembly. Using the two screws removed in step 1
of Removing Burner, install the new burner to the
inner door/ manifold assembly (rotate the assembly to
visually check the top portion of the burner assembly
and confi rm the orientation of the condensation drain
hole (see Figure 19 and note).

Caution Must Be Taken

Prior to installing the new inner door/manifold/burner
assembly, look inside the burner chamber to fully
understand the correct positioning of the burner assembly
and burner manifold tab. It may be necessary to use a
fl ashlight to ensure correct placement. Care must be taken
so as to not damage any electrical wiring, or components
as you are installing the new inner door/manifold/burner
assembly. Extra caution should be taken to ensure that
electrical wiring, fi berglass insulation or any other object
is not between door gasket and combustion chamber
shield. Note: If the burner door gasket (see Figure 9) is
worn or damaged it needs to be replaced. See section
“Door Gasket Replacement”.
Reinstalling Inner Door/Manifold/Burner Assembly

Insert the manifold/burner assembly in the burner

1.
chamber compartment, making sure that the tip of
burner manifold tab engages in the proper slot of the
bracket. The tip end of the burner manifold MUST be
placed in the slotted portion under the condensation
pan to obtain proper installation (see Figure 16).

Important:

• The tip end of the burner manifold MUST be placed
in the upper slotted portion for models with input rate
of 40,000 to 50,000 Btu/hr to obtain proper installation.

• The tip end of the burner manifold MUST be
placed in the lower slotted portion for models with
input rate of 60,000 to 75,000 Btu/hr to obtain proper
installation.
After confi rming no materials of any type are between

2.
door gasket and combustion chamber shield, align
the screws on the inner door with the screw holes
on the combustion chamber and tighten with 1/4”
nutdriver or 1/4” socket & ratchet (see Figure 15).
After tightening the inner door screws, visually inspect
area around door gasket and skirt for spaces or
gaps. The door gasket MUST be sealed completely
in order for the water heater to perform properly.
DO NOT OPERATE THE WATER HEATER IF THE
DOOR GASKET DOES NOT CREATE A SEAL
BETWEEN MANIFOLD DOOR AND COMBUSTION
CHAMBER.
Reconnect the manifold tube to the gas control valve/

3.
thermostat (Note: Do Not apply any thread sealant
at this connection). To prevent any cross threading
the manifold tube should be started by hand (turn
clockwise for natural gas, counter-clockwise for L.P.).
Upon tightening with the fi ngers and confi rming it has
not been cross threaded, tighten nut with a 3/4” open
end wrench (see Figure 15).

12

4.

Reconnect all the electrical connections to the bottom
of the gas control valve/thermostat, gently pushing
each connector up until it snaps into place (see Figures
10 & 15).

5.

Reconnect the electrical power to the water heater in
the wall outlet and turn the gas supply back “ON” to
the gas control valve/thermostat.

6.

Restart the water heater by following the directions on
the “Lighting and Operating Instructions” label located
on the front of the water heater.

7.

As the burner is heating (view flames through
viewport), test the manifold tube connection at the
gas control valve/thermostat by brushing on an
approved noncorrosive leak detection solution.
Important: Do Not splash any solution onto any
electrical connections.

8.

Upon verifying proper operation of the water heater,
replace the outer door.

OUTER DOOR

INSULATION

PAD

Figure 17

GASKET ON

REAR OF DOOR

MOUNTING CLIP

(1 EACH SIDE)

BURNER

ORIFICE

IGNITER

AND FLAME

ROD*

COMBUSTION

CHAMBER

OPENING

ELECTRICAL

CONNECTIONS

NOTE: OUTER DOOR AND INSULATION NOT SHOWN FOR CLARITY.

MANIFOLD
TUBE NUT

HEX HEAD

SCREWS

Figure 15

BURNER SUPPORT

BRACKET ­LOCATED IN THE
CENTRE OF THE

CHAMBER.

STRIGHT SLOT FOR

40-50K BURNERS

WITH STRAIGHT

MANIFOLD TUBES

CURVED SLOT FOR

60-75K BURNERS

WITH OFFSET

MANIFOLD TUBES

DRAIN HOLE

(AT 2 O’CLOCK

POSITION)

SCREWS

MANIFOLD

For 40,000 to
50,000 Btu/hr
models

ORIFICE

SCREWS

MANIFOLD

DOOR

GASKET

Figure 18

DRAIN HOLE

(AT 2 O’CLOCK

POSITION)*

BURNER

IGNITER

AND FLAME

ROD

Figure 16

For 60,000 to 75,000
Btu/hr models

Figure 19

DOOR

GASKET

Note: The drain hole must be at the 2 o’clock position,
directly opposite the igniter and fl ame rod.

13

BURNER ORIFICE

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

3/4” Open-End Wrench

•

Phillips Head Screwdriver

•

Ratchet with 1/4” socket or 1/4” nutdriver

•

Ratchet with 1/2” socket.

Removing Inner Door/Manifold/Burner Assembly

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Remove the outer door from the unit.

5.

Unplug all the electrical connections from the bottom
of the gas control valve/thermostat (see Figure 15).

6.

Using a 3/4” open end wrench remove the manifold
tube from the gas control valve/thermostat (turning
counter-clockwise for natural gas, clockwise for L.P.).
Grasp the manifold tube and push down slightly to
free the manifold tube from the gas control valve/
thermostat (see Figure 15).

7.

Remove the insulation pad on the inner door by cutting
it if necessary. Keep the insulation in a safe place for
reusing it later.

8.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the 2 hex head screws on the inner door so the inner
door/manifold/burner assembly can be removed (see
Figure 15).

9.

Remove inner door/manifold/burner assembly by
grasping the manifold, rotating it to the left to clear the
igniter and fl ame sensor and pulling back. Care should
be taken when inner door and burner assembly passes
through jacket opening that it does not damage any
of the electrical wiring (see Figure 17).

Removing Burner Orifi ce

1.

Burner may be hot. Wait until burner has cooled
off. After noting the position of the condensation
drain hole on the top of the burner, turn the inner
door/manifold/burner assembly upsidedown. Using
a Phillips head screwdriver, remove and retain the 2
screws attaching the burner to the manifold pipe (see
Figure 18 & 19).

2.

Using a ratchet with 1/2” socket, remove the burner’s
old orifi ce (Note: the burner orifi ces have different
threads dependent upon the gas type. Orifi ces for
natural gas have right-hand threads, orifi ces for L.P.
have leftt-hand threads (see Figures 18 & 19).

Installing Burner Orifi ce

Using a ratchet with 1/2” socket, install the new

1.
burner orifi ce (Note: the burner orifi ces have different
threads dependent upon the gas type. right-handed
threads for natural gas (turn clockwise to install)
and left-handed threads for propane gas (turn
counter-clockwise to install) (see Figures 18 & 19).
Note: Determine whether the orifi ce is tall or short and
DO NOT replace them with each other.
Care MUST be taken to ensure the burner is installed

2.
correctly on the inner door/manifold assembly. Position
the new burner upside down with the orientation of the
burner’s condensation drain as noted in “Removing
Burner Orifi ce” step 1.
Align the screw holes on the inner door/manifold

3.
assembly. Using the two screws removed in step 1
above, installed the new burner to the inner door/
manifold assembly (rotate the assembly to visually
check the top portion of the burner assembly and
confi rm the orientation of the condensation drain hole
as shown in the illustration) (see Figure 18 & 19).

Caution Must Be Taken

Prior to installing the new inner door/manifold/burner
assembly, look inside the burner chamber to fully
understand the correct positioning of the burner assembly
and burner manifold tab. It may be necessary to use a
fl ashlight to ensure correct placement. Care must be taken
so as to not damage any electrical wiring or components
as you are installing the new inner door/manifold/burner
assembly.
Extra caution should be taken to ensure that electrical
wiring, fi berglass insulation or any other object is not
between door gasket and combustion chamber shield.
Note: If the burner door gasket (see Figure 9) is worn
or damaged it needs to be replaced. See section “Door
Gasket Replacement”.
Reinstalling Inner Door/Manifold/Burner Assembly

Insert the manifold/burner assembly in the

1.
burner chamber compartment, making sure
that the tip of burner manifold tab engages in
the proper slot of the bracket (see Figure 16).

Important:

• The tip end of the burner manifold MUST be placed
in the upper slotted portion for models with input rate
of 40,000 to 50,000 Btu/hr to obtain proper installation.
* The tip end of the burner manifold MUST be
placed in the lower slotted portion for models with
input rate of 60,000 to 75,000 Btu/hr to obtain proper
installation.
After confi rming no materials of any type are between

2.
door gasket and combustion chamber shield, align
the screws on the inner door with the screw holes
on the combustion chamber and tighten with 1/4”
nutdriver or 1/4” socket & ratchet (see Figure 15).
After tightening the inner door screws, visually inspect
area around door gasket and skirt for spaces or
gaps. The door gasket MUST be sealed completely
in order for the water heater to perform properly.

14

DO NOT OPERATE THE WATER HEATER IF THE
DOOR GASKET DOES NOT CREATE A SEAL
BETWEEN MANIFOLD DOOR AND COMBUSTION
CHAMBER.
Reconnect the manifold tube to the gas control valve/

3.
thermostat (Note: Do Not apply any thread sealant
at this connection). To prevent any cross threading
the manifold tube should be started by hand (turn
clockwise for natural gas, counter-clockwise for L.P.).
Upon tightening with the fi ngers and confi rming it has
not been cross threaded, tighten nut with an 3/4” open
end wrench (see Figure 15).
Reconnect all the electrical connections to the bottom

4.
of the gas control valve/thermostat, gently pushing
each connector up until it snaps into place (see Figures
10 & 15).
Reconnect the electrical power to the water heater in

5.
the wall outlet and turn the gas supply back “ON” to
the gas control valve/thermostat.
Restart the water heater by following the directions on

6.
the “Lighting and Operating Instructions” label located
on the front of the water heater.
As the burner is heating (view flames through

7.
viewport), test the manifold tube connection at the
gas control valve/thermostat by brushing on an
approved noncorrosive leak detection solution.
Important: Do Not splash any solution onto any
electrical connections.
Upon verifying proper operation of the water heater,

8.
replace the outer door.

15

DOOR GASKET REPLACEMENT

DOOR GASKET

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

3/4” Open-End Wrench

•

3/4” Scraper

•

Ratchet with 1/4” socket or 1/4” nutdriver

•

Flashlight

Removing Inner Door/Manifold/Burner Assembly

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Remove the outer door from the unit.

5.

Unplug all the electrical connections from the bottom
of the gas control valve/thermostat (see Figure 7).

6.

Using a 3/4” open end wrench remove the manifold
tube from the gas control valve/thermostat (turning
counter-clockwise for natural gas, clockwise for L.P.).
Grasp the manifold tube and push down slightly to
free the manifold tube from the gas control valve/
thermostat (see Figure 7).

7.

Remove the insulation pad on the inner door by cutting
it if necessary. Keep the insulation in a safe place for
reusing it later.

8.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the 2 hex head screws on the inner door so the inner
door/manifold/burner assembly can be removed (see
Figure 7).

9.

Remove inner door/manifold/burner assembly by
grasping the manifold and pull back slowly. Rotating
it to the left to clear the igniter and fl ame sensor. Care
should be taken when inner door and burner assembly
passes through jacket opening that it does not damage
any of the electrical wiring (see Figure 9).

Removing The Door Gasket.

1.

Locate the gasket that is on the rear of the burner door
assembly (see fi gure 17 - 19).

2.

Pull off this gasket and using the 3/4” scraper, scrape
away and gasket stuck to the door.

3.

Using the 3/4” scraper, clean around the combustion
chamber opening to ensure no old gasket material is
stuck on the combustion chamber (Figure 17). Use
the fl ashlight to clearly illuminate this area. Take care
not to damage the mounting clips located on each
side of the opening.

16

Replacing The Door Gasket.

Remove the paper cover on the new door gasket. This

1.
will expose the gasket adhesive.
Position the gasket on the freshly cleaned door

2.
surface so that the adhesive fi rmly holds the gasket
to the door.
Smooth the gasket to avoid creases.

3.

Re-installing Inner Door/Manifold/Burner Assembly

Insert the manifold/burner assembly in the

1.
burner chamber compartment, making sure
that the tip of burner manifold tab engages in
the proper slot of the bracket (see Figure 8).

Important:

• The tip end of the burner manifold MUST be placed
in the upper slotted portion for models with input rate
of 40,000 to 50,000 Btu/hr to obtain proper installation.

• The tip end of the burner manifold MUST be
placed in the lower slotted portion for models with
input rate of 60,000 to 75,000 Btu/hr to obtain proper
installation.
After confi rming no materials of any type are between

2.
door gasket and combustion chamber shield, align
the screws on the inner door with the screw holes
on the combustion chamber and tighten with 1/4”
nutdriver or 1/4” socket & ratchet (see Figure 7). After
tightening the inner door screws, visually inspect
area around door gasket and skirt for spaces or
gaps. The door gasket MUST be sealed completely
in order for the water heater to perform properly.
DO NOT OPERATE THE WATER HEATER IF THE
DOOR GASKET DOES NOT CREATE A SEAL
BETWEEN MANIFOLD DOOR AND COMBUSTION
CHAMBER.
Reconnect the manifold tube to the gas control valve/

3.
thermostat (Note: Do Not apply any thread sealant
at this connection). To prevent any cross threading
the manifold tube should be started by hand (turn
clockwise for natural gas, counter-clockwise for L.P.).
Upon tightening with the fi ngers and confi rming it has
not been cross threaded, tighten nut with a 3/4” open
end wrench (see Figure 7).
Reinstall the insulation pad which was removed in

4.
step 7 above.
Reconnect all the electrical connections to the bottom

5.
of the gas control valve/thermostat, gently pushing
each connector up until it snaps into place (see Figures
7 & 10).
Reconnect the electrical power to the water heater in

6.
the wall outlet and turn the main gas supply back “ON”
to the gas control valve/thermostat.
Restart the water heater by following the directions on

7.
the “Lighting and Operating Instructions” label located
on the front of the water heater. Test gas connections
by brushing on an approved non-corrosive leak
detection solution. (Note: Do not splash the solution
on control. If a leak is detected, shut the water heater
down by following the directions on the “Lighting and
Operating Instructions”. Repair the leak(s) and repeat
this step.
Upon verifying proper operation of the water heater,

8.
replace the insulation and outer door.

17

CONTROL MODULE REMOVAL/REPLACEMENT

ELECTRONIC CONTROL MODULE

Important: Do not remove the entire gas control assembly

from the water heater.
Important: Use only factory authorized replacement parts.
If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

T15 Torx screwdriver

•

Flat-blade screwdriver

Removing Electronic Control Module

1. Set the gas control valve/thermostat to its lowest setting
by turning the knob counter-clockwise to the VAC point
(see Figure 20).

2. Turn gas control switch to the “OFF” position and turn
off the gas supply to the unit (see Figure 20).

3. Disconnect the electrical power to the water heater
from the wall outlet.

4. Remove the front Torx screw at the bottom of the gas
control valve/thermostat as illustrated in Figure 21.

5. Use a fl at-blade screwdriver to release the two tabs at
the top of the gas control valve/thermostat and lift the
electronic control straight up (see Figures 22 & 23).

6. Disconnect the temperature sensor cable.

Note: When removing the control module from the

gas control assembly, disengage the pins on the valve
module without causing damage.

7. Re-assemble in the reverse order.

Note: During re-assembly, align the pins on the valve

module to their proper location in the control module
without causing damage.

FRONT TORX
SCREW

Figure 21

ELECTRONIC
CONTROL
MODULE

VALVE MODULE

Figure 20

LIFT THE
ELECTRONIC
CONTROL
STRAIGHT UP

THREADED CONTROL
FITTING
(DO NOT REMOVE
FROM WATER HEATER)

Figure 22

18

ELECTRONIC
CONTROL
MODULE

THREADED CONTROL
FITTING
(DO NOT REMOVE
FROM WATER HEATER)

DISCONNECT
TEMPERATURE
SENSOR CABLE
HERE

TABS

Figure 23

19

VALVE MODULE REMOVAL/REPLACEMENT

VALVE MODULE

Important: Do not remove the entire gas control assembly

from the water heater.
Important: Use only factory authorized replacement parts.
If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

T15 Torx screwdriver

•

Flat-blade screwdriver

Removing Valve Module

1. Set the gas control valve/thermostat to its lowest

setting by turning the knob counter-clockwise to the
VAC point (see Figure 20).

2. Turn gas control switch to the “OFF” position and turn

off the gas supply to the unit (see Figure 20).

3. Disconnect the electrical power to the water heater

from the wall outlet.

4. Remove the Electronic Control Module as outlined in

“Removing Electronic Control Module” above.

Note: When removing the control module from the

gas control assembly, disengage the pins on the valve
module without causing damage.

5. Remove the screw and the ground tab with a Torx

screwdriver (see Figure 24).

6. Insert a fl at-blade screwdriver between the casting

and the locking tabs at the bottom of the valve.

7. Carefully pry against the casting until it barely slides

past the locking tab edge.

8. Repeat on the opposite side.

9. Replace the valve.

Note: When replacing the valve, do not apply pressure

with the hand on the valve pins.

10. Re-assemble in the reverse order.

Note: During re-assembly, align the pins on the valve

module to their proper location in the control module
without causing damage.

VALV E

PINS

SCREW AND
GROUND TAB

CASTING AND
LOCKING TAB

CASTING AND
LOCKING TAB

Figure 24

20

TEMPERATURE SENSOR AND

CABLE REMOVAL/REPLACEMENT

TEMPERATURE SENSOR AND CABLE

Important: Do not remove the entire gas control assembly

from the water heater.
Important: Use only factory authorized replacement parts.
If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

T15 Torx screwdriver

•

Flat-blade screwdriver

Removing Temperature Sensor and Cable

1. Set the gas control valve/thermostat to its lowest setting
by turning the knob counter-clockwise to the VAC point
(see Figure 20).

2. Turn gas control switch to the “OFF” position and turn
off the gas supply to the unit (see Figure 20).

3. Disconnect the electrical power to the water heater
from the wall outlet.

4. Remove the Electronic Control Module as outlined
in “Removing Electronic Control Module” section
above.

Note: When removing the control module from the

gas control assembly, disengage the pins on the valve
module without causing damage.

5. Remove the Valve Module as outlined in ”Removing
Valve Module” section above.

6. Use a screwdriver to pry under the sensor retainer
fi nger to remove the temperature sensor and cable
(see Figure 25).

7. Re-assemble in the reverse order.

Note: When replacing the valve, do not apply pressure

with the hand on the valve pins.

Note: During re-assembly, align the pins on the valve

module to their proper location in the control module
without causing damage.

SENSOR
RETAINER "FINGER"

NOTE: USE CAUTION
WHEN REPLACING
THE VALVE TO NOT
APPLY PRESSURE
ON THE VALVE PINS.

TEMPERA­TURE SENSOR
CABLE UNDER
THE RETAINING
TAB

THREADED CONTROL
FITTING
(DO NOT REMOVE
FROM WATER HEATER)

Figure 25

21

GAS VALVE REMOVAL/REPLACEMENT

GAS CONTROL VALVE

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

3/4” Open-End Wrench

•

short length of 1/2” threaded pipe

•

Pipe Wrench

Removing Gas Control Valve

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
off the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Release water pressure by opening a nearby hot
water faucet, let run until water is cool to touch. Turn
off water supply to the water heater.

5.

Remove the outer door from the unit.

6.

Connect a drain hose to the drain valve and run it to
an adequate drain or to the exterior of the building.
Open the water heater drain valve and allow the water
to drain from the tank.

7.

Unplug all the electrical connections from the bottom
of the gas control valve/thermostat (see Figure 26).

8.

Using a 3/4” open end wrench remove the manifold
tube from the gas control valve/thermostat (turning
counter-clockwise for natural gas, clockwise for L.P.).
Grasp the manifold tube and push down slightly to
free the manifold tube from the gas control valve/
thermostat (see Figure 26).

9.

Ensuring that the gas supply line is turned off,
disconnect the gas piping at the ground joint union,
then remove the gas piping from the gas control
valve/thermostat.

10.

Remove any other fi ttings that may be installed on the
threaded pipe to the gas control valve/thermostat.

11.

After ensuring the water heater is completely drained,
thread a short length of 1/2” threaded pipe into the
inlet connection of the gas control valve/thermostat
and use it to turn the gas control valve/thermostat
counter-clockwise to remove (see Figure 27). Do not
use any type of wrench on the valve body as it may
cause damage to the gas control valve/thermostat
assembly.

Installing Gas Control Valve

Do not apply any sealant tape to the gas control/

1.
thermostat threads that screw into the tank. The
threads have a pre-applied white sealing material.
Thread a short length of 1/2” threaded pipe into

2.
the inlet connection of the new gas control valve/
thermostat and use it to turn the gas control valve/
thermostat clockwise to tighten into place (Note: Do
Not over tighten or damage may result, but it needs
to be water tight (see Figure 27).
Remove the 1/2” threaded pipe from the gas control

3.
valve/thermostat.
Reconnect the gas piping to the gas control valve/

4.
thermostat, use Tefl on® tape or an approved pipe
sealant on threads of the piping.
Close the drain valve and turn on the cold water supply

5.
line fi lling the tank completely with water. Purge the
water lines of any excess air by opening a hot water
faucet allowing the water to fl ow for a minimum of 3
minutes, allowing the tank to fi ll completely.
Reconnect the manifold tube to the gas control valve/

6.
thermostat (Note: Do Not apply any thread sealant
at this connection). To prevent any cross threading
the manifold tube should be started by hand (turn
clockwise for natural gas, counter-clockwise for L.P.).
Upon tightening with the fi ngers and confi rming it has
not been cross threaded, tighten nut with an 3/4” open
end wrench (see Figure 26).
Reconnect all the electrical connections to the bottom

7.
of the gas control valve/thermostat, gently pushing
each connector up snapping into place (see Figures
10 & 26).
Turn on the gas supply to the unit and test the gas

8.
supply line and union connections by brushing on an
approved noncorrosive leak detection solution. (Note:
Do not splash the solution on control. If a leak is
detected, shut the water heater down by following the
directions on the “Lighting and Operating Instructions”.
Repair the leak(s) and repeat leak test).
Reconnect the electrical power to the water heater in

9.
the wall outlet and turn the gas supply back on to the
gas control valve/thermostat.
Restart the water heater by following the directions on

10.
the “Lighting and Operating Instructions” label located
on the front of the water heater.
As the burner is heating (view flames through

11.
viewport), test the manifold tube connection at the
gas control valve/thermostat by brushing on an
approved noncorrosive leak detection solution.
Important: Do Not splash any solution onto any
electrical connections.
Upon verifying proper operation of the water heater,

12.
replace the outer door.

22

ELECTRICAL

CONNECTIONS

NOTE: OUTER DOOR AND INSULATION NOT SHOWN FOR CLARITY.

MANIFOLD
TUBE NUT

HEX HEAD

SCREWS

Figure 26

THREADED

PIPE

“HANDLE”

Figure 27

23

BLOWER REMOVAL/REPLACEMENT

BLOWER

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

Ratchet with 5/16” socket or 5/16” nutdriver

•

Ratchet with 1/4” socket or 1/4” nutdriver

Removing Blower

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Use a 5/16” nutdriver to loosen the screw on
the upper gear clamp of the rubber coupling
adaptor connecting the venting to the blower. Slowly
pull the vent from the adaptor (see Figure 28).
Note: The rubber coupling adaptor will be different
based on the venting size (2” or 3” vent pipe).

5.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the screw on the junction box. Remove and retain the
screw and junction box cover. Disconnect the power
and ground connectors (see Figure 28).

6.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen,
remove and retain the 6 hex head screws so the blower
assembly can be removed. Remove the blower while
carefully passing the power and ground connectors
through the junction box opening (see Figure 28).
Important: When removing the blower, care must
be taken to pass the power and ground connectors
through the junction box opening so the wires and
blower do not get damaged.

Reconnect the electrical power to the water heater in

5.
the wall outlet and turn the gas supply back “ON” to
the gas control valve/thermostat.
Restart the water heater by following the directions on

6.
the “Lighting and Operating Instructions” label located
on the front of the water heater.

Note: This power vent heater will accept a 2” or 3” rubber
outlet coupling, depending on the size of the water heater.
This coupling, mounted in the vertical position, accepts
the vent piping and is attached as shown in Figure 28.
Refer to the Manual to determine vent pipe sizing for
your application. The blower assembly may be rotated 90
degrees clockwise or counter-clockwise to allow horizontal
venting in areas having restricted space above the water
heater (see “Rotating the Blower” section).

VENTING

JUNCTION

BOX

COVER

JUNCTION

BOX

SCREWS

BLOWER

ASSEMBLY

Installing Blower

1.

Pass the power and ground connectors through the
junction box opening and place the blower on top of
the water heater.

2.

Reconnect the power connector and the ground

SCREW

connector. Reinstall the junction box cover and screw
removed in step 5 above. Tighten with 1/4” nutdriver
or 1/4” socket & ratchet.

3.

Align the screw holes on the blower assembly with
those on the top of the heater. Using the six screws
removed in step 6 above, install the blower assembly

Figure 28

and tighten with 1/4” nutdriver or 1/4” socket & ratchet
(see Figure 28).

4.

Reinstall the vent by pushing it into the adaptor. After
confi rming the vent is properly seated in the adaptor, use
a 5/16” nutdriver to tighten the screw on the gear clamp
of the adaptor connecting the venting to the blower.
Important: This connection must be properly sealed
to prevent the leakage of the products of combustion
into the living area.

24

ROTATING THE BLOWER

BLOWER EXHAUST DIRECTION

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

Ratchet with 11/32” socket or 11/32” nutdriver

The blower assembly may be rotated 90 degree clockwise
or counterclockwise to allow horizontal venting in areas
having restricted space above the water heater. To rotate
the blower outlet, remove the four nuts with 11/32” nut
driver (see Figure 29), securing the fl ue collector to the
blower housing. Pull the blower assembly forward to free
it from the mounting studs. Rotate the blower housing
clockwise or counter-clockwise and align the four holes
and screws together. Reattach the blower housing to the
fl ue collector.

11/32” nut

Figure 29

This power vent heater can accept 2” or 3” rubber outlet
coupling, depending on the capacity of the water heater.
This coupling, mounted in the vertical position, accepts the
vent piping and is attached as shown in Figure 28.

25

PRESSURE SWITCH REMOVAL/REPLACEMENT

PRESSURE SWITCH

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the
installation, you should not proceed, but get help from a
qualifi ed service technician.
Tools required:

•

Phillips Head Screwdriver

•

Ratchet with 1/4” socket or 1/4” nutdriver

Removing Pressure Switch

1.

Set the gas control valve/thermostat to its lowest
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).

2.

Turn gas control switch to the “OFF” position and turn
“OFF” the gas supply to the unit (see Figure 3).

3.

Disconnect the electrical power to the water heater
from the wall outlet.

4.

Use a 1/4” nutdriver or 1/4” socket & ratchet to loosen
the screw on the junction box. Remove and retain the
screw and junction box cover (see Figure 30).

5.

Remove the air pressure tubing from the air pressure
switch by pulling upward on the tubing at the
connection to the air pressure switch.

6.

After noting the position of each electrical fl ag terminals,
remove the two (2) electrical fl ag terminals from the
switch by pulling outward and off the switch.

7.

Using a hex head screwdriver, remove and retain the
2 screws securing the bracket to the junction box (see
Figure 30).

8.

Using a hex head screwdriver, remove and retain the
2 screws securing the pressure switch to the bracket
(see Figure 30).

Installing Pressure Switch

Using a hex head screwdriver, secure the new pressure

1.
switch to the bracket with the screws removed in step
8 above. Care should be taken to ensure the proper
orientation of the bracket and pressure switch (see
Figure 30).
Using a hex head hex screwdriver, secure the bracket

2.
to the junction box with the screws removed in step 7
above (see Figure 30).
Reattach the two (2) electrical flag terminals by

3.
pushing the flag terminals onto the switch. Care
MUST be taken to ensure that each of the electrical
fl ag terminals is in its original position.
Reattach the air pressure tubing to the air pressure

4.
switch by pushing the tubing onto the connector until
the end of the tubing reaches the shoulder of the
connector.
Replace the blower’s junction box door by reusing the

5.
screw removed in step 4 above.
Reconnect the electrical power to the water heater in

6.
the wall outlet and turn the gas supply back “ON” to
the gas control valve/thermostat.
Restart the water heater by following the directions on

7.
the “Lighting and Operating Instructions” label located
on the front of the water heater.

AIR

PRESSURE

TUBING

JUNCTION

BOX

COVER

BRACKET

JUNCTION

BOX

AIR

PRESSURE

SWITCH

SCREWS

SCREW

Figure 30

26

FV SENSOR

FLAMMABLE VAPOR SENSOR

When using a gas fi red water heater there is a risk of
fl ammable vapors entering the combustion chamber, being

ignited by the burner fl ame and causing a fl ashback. In
order to detect such fl ammable vapors before they enter
the combustion chamber, this water heater is equipped
with a fl ammable vapor sensor (FVS). It is a chemical-
absorption based sensor that is connected to the gas
control/thermostat (see Figure 31). When exposed to

fl ammable vapors it will trigger the control to stop the
fl ow of gas and enter the FVS lockout state. While in the

FVS lockout state the LED on the control will fl ash the
gas lockout code. Refer to the “Gas Control Led Status
Codes” section for an explanation of the codes applicable
to the control installed on your water heater. If an FVS
lockout occurs, check around the water heater for sources
of chemical contamination such as fl ammable vapors
including gas vapors, solvents, paint and thinners as well
as sources of water and detergents.

Note: Resetting the heater will reset the FVIR circuit if
all sources of contamination have been removed and the
sensor clears. If all sources of contamination have been
removed and the system will not reset, the sensor will
need to be replaced.

If there is a problem with the wiring of the fl ammable vapor
sensor or the fl ammable vapor interface the LED will fl ash
the failure status code (see “Troubleshooting Guide”).

* ROTATE LEFT (CCW)
TO REMOVE

COVER*

MOUNTING

BRACKET

FLAMMABLE

VAPOR SENSOR

(PULL TO REMOVE)

Figure 31

27

CLEANING THE COMBUSTION CHAMBER

Follow procedure outlined in “Removing Inner Door/

1.
Manifold/Burner Assembly”.
Use a vacuum cleaner/shop vac to remove all loose

2.
debris in the combustion chamber.
Reassemble following the procedure under “Installing

3.
Inner Door/Manifold/Burner Assembly”.

28

CLEANING THE BLOWER

BLOWER

In dusty and contaminated air conditions, the interior of
the blower and the blower wheel may require periodic
cleaning. This is often indicated by nuisance failures
of the air pressure switch or the high limit temperature
control. A collection of dust or debris on the rear blower
air intakes can also indicate reduced blower capacity. To
clean the inside of the blower assembly and the blower
wheel requires the removal of the blower/motor from the
mounting plate located on the top of the heater. Tools
required include an 11/32” nut driver, small (1”) paintbrush,
toothbrush and vacuum cleaner.

Set the gas control valve/thermostat to its lowest

1.
setting by turning the knob counter-clockwise to the
VAC point (see Figure 3).
Turn gas control switch to the “OFF” position and turn

2.
“OFF” the gas supply to the unit (see Figure 3).
Disconnect the electrical power to the water heater

3.
from the wall outlet.
Disconnect the vent piping from the top of the blower.

4.
Loosen the lower gear clamp that holds the rubber
coupling to the blower.
Remove and retain the (4) 11/32” nuts located on

5.
the back of the blower with the nutdriver (see Figure

32).
Holding the blower motor and the blower housing,

6.
pull the assembly forward to disengage it from the
mounting plate. The blower will still be connected to
the junction box so exercise care not to stress the
wiring.
Accessing the blower wheel through the outlet, use

7.
the paint brush to brush off the outer edge of the
blower wheel to dislodge the dirt stuck on the blades
and the inside of the housing. Rotate the wheel until
all blades are clear. Note: The wheel is a balanced
component. Do not bend, dent or distort the blades as
this can upset the wheel balance and affect the blower
operation. Vacuum out the loosened dirt.
Accessing the inside of the blower wheel through the

8.
rear of the housing, gently brush off the inside of the
blades using the toothbrush. Again, take care not to
distort the blades. Rotate the wheel until all blades
are cleaned and vacuum the debris.
Inspect the fl ue collector hood (still attached to the

9.
heater) and vacuum out the dust and debris that may
have accumulated.
With all parts cleaned and the blower wheel turning

10.
freely, reinstall the blower to the mounting plate
aligning the (4) studs and pushing tight against the
mounting plate.
Reinstall the (4) 11/32” nuts and tighten securely. All

11.
(4) nuts must be in place and secure to safely operate
the blower.
Reattach the vent piping and coupling to the top of the

12.
blower, tighten the bottom gear clamp and ensure the
piping is secure.

13.

With all components clean and secure, reconnect the
electrical power to the heater.
Reset the thermostat to the desired temperature

14.
setting and turn the gas control switch back to the
“ON” position. Note: If the water in the heater is hot,
the unit will wait to operate until there is a need for
more hot water.

VENT

PIPE

MOTOR

BLOWER

MOUNTING

PLATE

COUPLING

GEAR

CLAMP

FLUE

COLLECTOR

HOOD

REAR

BLOWER AIR

INTAKES

Figure 32

11/32”
NUTS

29

TECHNICAL BULLETINS

WATER HAMMER

GENERAL Water hammer is the destructive force, pounding noise and vibration in a piping system when water

fl owing through a pipeline is stopped abruptly. When water hammer occurs, a high intensity pressure
wave travels back through the piping system until it reaches a point of some relief. The shock wave
will then surge back and forth between the point of relief and the point of stoppage until the destructive
energy is dissipated in the piping system. The violent action accounts for “banging”, “thumping”, and/or
intense vibration in the pipe line. Although noise is generally associated with the occurrence of water
hammer, it can occur without audible sound or noise. Quick closure of valves always causes some
degree of shock with or without noise. The common cause of water hammer is single lever faucets
(sinks/lavatories) or automatic solenoid valves dishwashers, washing machines, etc.). The speed of
the valve closure time is directly related to the intensity of the surge pressure.

EFFECTS The damage from water hammer can manifest itself in a number of ways. The most common are:

• Expanded Tank Shell - This can be demonstrated by measuring the circumference at various
locations along the shell. Pressures in excess of the maximum design working pressure can cause
permanent deformation of the shell. Note: The continuous expansion of the tank shell may cause
the tank to rupture at a welded seam.

• Collapsed Flue Tube - This will choke off the ability to vent the products of combustion causing
the fl ame and/or combustion to spill out from the combustion chamber. Often this will occur where
thinning of the fl ue tube walls has occurred due to contamination of the combustion air or because
of excessive condensation.

• Inverted or Deformed Tank Heads - Often this accompanies collapsed fl ues, but one or both heads
can be deformed.

THE FIX The only effective means of control is to install water hammer arrestors. These devices have

diaphragms which separate an air chamber from the water in the piping system. As the shock wave
reaches this device, the air chamber absorbs the shock. Arrestors should be located as close as
possible to the source of the shock wave.

NOTES Since water hammer exposes the equipment to pressures in excess of its design limits, failures

caused by water hammer are not eligible for warranty consideration.

MINERAL BUILD-UP

SYMPTOMS • Rumbling

• Crackling

• Popping

CAUSE With the increase in fuel costs and hot water consumption, deliming has become a necessity of modern

maintenance. Lime (CaCO3), is the most notable factor when discussing water hardness. Lime is
present in every water system to some degree. Since lime is inversely soluble (the more you heat,
the more lime comes out), higher usage, excessive hardness, and increased heating surface can
lead to a high incidence of “limed-up” heaters. Symptoms often include a popping of water trapped
under lime deposits or the sizzling of water trapped next to elements, boiling it to steam.

THE FIX Treatment of a “limed-up“ heater is relatively simple. Since CaCO3 is a base, the easiest way to

dissolve it so it can be fl ushed from the heater is with an acid. The most commonly used is phosphoric
acid at a food-grade level. Two available treatments are Mag-Erad® and Un-Lime®. Any well stocked
plumbing supply house should have a deliming solution available. The directions on the product
should be followed explicitly.

30

CONDENSATION

SYMPTOMS The water heater appears to be releasing water while the main burner is on or water is found

surrounding the heater shortly after the water heater has been used. This section explains why fl ue
gases condense and how you can differentiate between condensation and leaking.

CAUSES Condensate is the result of air borne water vapor being chilled below the dew point. The dew point

is the temperature at which water vapor turns into liquid. Low incoming water temperatures cool the
piping and the heat transfer surfaces of the water heater. When the main burner comes on, the hot
fl ue gases turn into condensate upon contact with these surfaces. The typical home water heater
will produce about one-half gallon of water vapor during every hour of operation. Condensate is
often mistaken for leaking. Newer heaters will condensate more than older heaters because modern
water heaters are much more effi cient than their predecessors. The newer heaters utilize as much
of the energy out of the main burner fl ame as possible. This lowers the fl ue gas and tank storage
temperature and closer to the dew point temperature.

THE FIX To distinguish between a condensating water heater and a leaking water heater:

1. Wipe up any water under the heater,

2. Turn gas control switch to the “OFF” position,

3. Wait 8 hours, check for water accumulation under the heater.

4. Condensation should stop when the entire tank water is heated above approximately 115°F.
a. If no water is under the heater, the water heater was condensating.
b. If water is under the heater, check further for a loose fi tting. If all fi ttings are tight and the tank

is leaking, replace the water heater. Leaking heaters cannot be “repaired”.

DISCOLORED WATER

SYMPTOMS Rusty, brown, black, or yellow water appearing in the hot water.

CAUSES Complaints of discolored water are commonly blamed on water heaters and storage tanks, but in

fact, it is a rare occurrence for today’s high quality glass lined tanks to have a lining failure signifi cant
enough to allow water to contact enough bare metal to discolor the contents of even a small tank.
The most common cause of “rusty” water is a non-toxic iron reducing bacteria, scientifi cally termed
Crenothrix, Leptothrix, and Gallionella. Iron bacteria is commonly found in soil, water wells, water
treatment plants and water distribution piping systems where soluble iron exceeds 0.2 ppm, higher
levels make conditions even more favorable. Soluble iron in the water provides food for the bacteria.
Rusty discolored water is the end result of the bacteria feeding process. Water heaters and storage
tanks usually require new anode rods as presence of iron bacteria contributes to premature anode
failure.

The requirements for the bacteria to thrive are:

• Elevated levels of iron and manganese in the water.

• Water with little or no dissolved oxygen.

• Temperatures below 138°F.

Items that can increase the potential for this bacteria are:

• Water softeners.

• Well water.

• Long periods of no water movement.

TREATMENT The simplest treatment available is shock-chlorination of the system. This is a surface treatment, and

often requires repeated trials in heavily infected systems. The chlorination of a system requires that
you follow each step explicitly to avoid an untreated portion of the piping system from re-infecting
another part. See the “Chlorination Procedure” section.

NOTES Since rusty water is caused by a bacteria presence and is not caused by the water heater, any

treatment would not be considered warranty related.

31

SMELLY WATER

SYMPTOMS Rusty, brown, black, or yellow water appearing in the hot water.

CAUSES The most common cause of “smelly water” is a non-toxic sulfate reducing bacteria, scientifi cally

termed Divibrio Sulfurcans. This bacteria often enters the water system through construction or a
break in ground piping. The bacteria create the energy it needs to survive by converting sulfate (SO

4

to hydrogen sulfi de (H2S) gas you smell in the water. Hydrogen sulfi de gas is distinctive because
of its rotten egg-like stench. Its presence can severely affect the taste as well as the odor of the
water. Occasionally this bacteria can be accompanied by black deposits, the result of pipe and fi tting
corrosion. In extremely high concentrations, hydrogen sulfi de gas can be toxic though the gas is
detectable long before harmful levels are reached.

The requirements for the bacteria to thrive are:

• Elevated levels of iron and manganese in the water.

• Water with little or no dissolved oxygen.

• Temperatures below 138°F.

Items that can increase the potential for this bacteria are:

• Water softeners.

• Well water.

• Long periods of no water movement.

Other factors that may contribute to smelly water:

• Chlorides of Magnesium and Calcium leave a bitter taste.

• Chloride of Sodium produces a salty taste.

• Sulfates (50 ppm) gives a medicinal taste.

• Carbon Dioxide in low pH water gives fi zzy water.

• Iron and tannic waters also give a bad taste and odor.

TREATMENT The simplest treatment available is the shock-chlorination of the system. This is a surface treatment,

and often requires repeated trials in heavily infected systems. The chlorination of a system requires
that you follow each step explicitly to avoid an untreated portion of the piping system from re-infecting
another part. See the “Chlorination Procedure” section. Longer lasting solutions include chlorination
or aeration of the water supply.

NOTES Since rusty water is caused by a bacteria presence and is not caused by the water heater, any

treatment would not be considered warranty related.

)

32

CHLORINATION PROCEDURE

CAUSES The chlorination procedure is used to eliminate various bacteria that accumulate and grow in water

heaters. These bacteria often cause odorous or discolored water conditions.

TREATMENT The simplest treatment available is the shock-chlorination of the system. This is a surface treatment,

and often requires repeated trials in heavily infected systems. The chlorination of a system requires
that you follow each step explicitly to avoid an untreated portion of the piping system from re-infecting
another part. Longer lasting solutions include chlorination or aeration of the water supply.

PROCEDURE Please read the steps of the chlorination procedure prior to beginning. If you feel uncomfortable

performing any of these steps, contact a service person to perform this procedure for you.

STEP 1 Turn off the gas and electric supply to the tank.

STEP 2 Turn off the cold water supply valve to the tank.

STEP 3 Open a nearby hot water faucet to relieve the vacuum.

STEP 4 Drain all the water from the tank (a water-hose may be needed).

STEP 5 Remove the anode rod(s), and close the drain valve.

STEP 6 Using a funnel in the anode opening add one gallon of household chlorine bleach for every 25 gallons

of tank capacity.

STEP 7 Reinstall anode rod(s) after inspecting and replacing as needed.

STEP 8 Open cold water supply valve and refi ll the system. Then draw the water to every hot water fi xture,

until the smell of chlorine is detected. Operate dish and clothes washers until a noticeable amount
of the chlorine is detected as well. All hot water lines must receive treatment.

STEP 9 Leave the chlorine solution undisturbed for one hour or more.

STEP 10 After the contact time has elapsed, drain the tank according to steps 2, 3, & 4.

STEP 11 Close the drain valve and refi ll the tank. Allow the tank to sit for 15 minutes. Repeat steps 2, 3, and

4. Continue to fl ush the tank if the water is discolored or contains a chlorine odor.

STEP 12 Close the drain valve and refi ll the tank. Flush all chlorine from the piping by opening every hot water

outlet/ appliance.

STEP 13 Return hot water heating system to service by following the recommended start-up procedure posted

on the unit or in the manual.

NOT ENOUGH HOT WATER

CAUSES • The heating capacity of the water heater has been exceeded: complaints regarding an insuffi cient

supply of hot water are typically the result of a water heater that cannot meet the demands of the
residence (both people and appliances). The demand for suffi cient hot water may also be exceeded
if additional people and/or appliances are added to the residence.

• Operating Set Point is too low.

• Mineral build-up.

• Hot water supply valve(s) to fi xtures not fully open.

• Inlet/outlet water piping connections to water heater reversed.

• Dip tube inside water inlet connection missing.

THE FIX Compare hot water requirements with the capacity of the water heater. If necessary, install a water

heater with greater capacity.

• Turn temperature knob to desired temperature as described in the Manual.

• Drain the tank (see “Draining and Flushing” section in the Manual). Determine if water treatment
is needed.

• Check to see if hot water supply valve is fully open, check inlet/outlet piping connections to water
heater are not reversed, check to see if the dip tube inside water inlet connection is not missing.

33

THERMAL EXPANSION

SYMPTOMS • Effects are only noticeable after hot water use followed by periods of no water use.

• Relief valve drips during any recovery cycle when no hot or cold water is used.

• Hot water pipes creak while water heater is recovering and all valves are closed.

• Tanks or other components of the water supply system fail prematurely.

• A metallic creaking noise might actually be heard in the location of the heater as the pressure is
relieved and the stretched tank returns to a natural shape.

• Faucet drips during any recovery cycle when no hot or cold water is used.

• Water surges when a faucet is fi rst opened and then pressure drops.

CAUSE The water in a water heating system expands when it is heated and increases in volume. Since water

will not compress (like air), system designers must include provisions for thermal expansion. (Water
in a closed tank at 50 psi, when heated just 10 degrees, will reach a pressure of 250 psi). Many
water supply systems have check valves or back fl ow preventers at the water meter to prevent any
possible contamination of the public water supply by the accidental back-fl ow of contaminated water
into the supply mains. These check valves are often required by code, and some cities are even
installing the check valves. They serve a useful purpose. Do not remove them! The use of pressure
reducing valves (PRV) is another cause. PRVs are designed to conserve water and prolong fi xture
life. Many PRVs also act as very effective check valves. Again, do not remove them! Water softeners
in the system may also act as back-fl ow preventers.

TEST Follow these easy steps to diagnose thermal expansion:

• Turn gas control switch to the “OFF” position, and install a water pressure gauge with dead hand
on the drain valve. Open the drain valve, so the gauge reads system pressure.

• Open a hot water tap and allow 15% to 20% of the tanks volume to run out. Shut off the drain valve
and make sure that no other fi xture in the system, hot or cold, is open. Make sure that outside
fi xtures, if they are on the same system, are turned off too. Any water leaks or use will make the
test meaningless.

• Check the water pressure gauge, and turn the pointer so it lines up with the pressure indicating
needle. Turn the gas control switch “ON”, so the heater cycles on. Watch the pressure gauge.

• If the system is closed, the pressure will start to climb steadily and rapidly. A small amount of
thermal expansion control may be built into the system because of trapped air pockets or a water
hammer arrestor. In that case the pressure will increase slightly, hold steady for a short time and
then rapidly increase. The temperature and pressure relief valve (T&P) or PRV should open and
release water once the pressure reaches the maximum setting on the valve. The valve will close
once the pressure falls below the pressure setting of the valve.

THE FIX The ideal fi x involves the use of a pressure reducing valve if supply pressures are above 60 to 70 psi,

and a properly sized expansion tank. The PRV reduces supply pressures to 40 to 60 psi allowing an
economically priced and sized expansion tank to be used. The PRV also offers the benefi t of saving
water and prolonging the life of water fl ow valves. The PRV is not required if the system already has
one or if high supply pressures are desired. A supply water pressure of 80 PSI is a maximum set
by many codes. The PRV is installed between the check valve and the water heating system. The
expansion tank is installed between the PRV and the water heating system. Follow the manufacturers
instructions for installing the expansion tank. Run the thermal expansion check again. The pressure
should increase only slightly then hold steady throughout the recovery cycle. The expanded water
is fl owing back from the heater and into the pressurized storage bladder of the expansion tank. Air
pressure will force this water out of the expansion tank into the supply once usage resumes. DO NOT
DEPEND ON THE TEMPERATURE & PRESSURE VALVE (T&P VALVE) TO HANDLE THERMAL
EXPANSION! The T&P valve manufacturers designed the valve to be an emergency relief device
only. The T&P Valve could be subject to reduced effectiveness or failure.

WARNING Thermal expansion of water, if not compensated for in system design, will lead to the early failure

of components. These failures are not covered by the manufacturer’s warranty, so it is extremely
important that everyone be aware of the causes, symptoms and solutions to thermal expansion in
a closed water heating system.

34

LEAKING TEMPERATURE AND PRESSURE RELIEF VALVE

SYMPTOMS • Water seeping around the relief valve tank connection.

• Leakage at the threaded portion of the relief valve connection.

• Intermittent weeping and/or dribbling from the relief valve.

• Large volume of hot water sporadically discharged from the relief valve.

CAUSE The temperature and pressure relief valve (T&P) is a safety device limiting temperature and pressure

levels in a water heater. Each T&P has both a temperature and pressure rating. Normally, the
temperature and pressure relief valve will have a temperature rating of 210°F. A probe (part of the
relief valve) extends into the tank measuring the stored water temperature. This probe must be within
the top six inches of the water heater. If the water heater’s thermostat malfunctions, higher than
normal water temperatures could be produced. Once the probe senses a temperature approaching
its temperature rating, the relief valve will open to full capacity releasing “very hot” water until the
temperature is below its reset temperature. The pressure rating on the relief valve should be the
same or less than the certifi ed working pressure of the tank (generally 150 psi) and be below the
lowest maximum working pressure rating of any system components. Once the pressure in the tank
reaches the valve’s pressure rating, it will slightly open relieving the pressure. Relieving of pressure
can be noted as “dribbling” or “weeping” water from the relief valve. If an incorrectly sized temperature
and pressure relief valve is installed, the warranty will be void.

THE FIX Follow these easy steps to diagnose thermal expansion:

• Intermittent weeping and/or dribbling at the relief valve - The relief valve relieves water slowly
when actuating on pressure. A closed system can cause pressure to increase in the system. This
condition is called thermal expansion. For additional information regarding thermal expansion
please see thermal expansion section on of the Installation and Operating Manual.

• Leaking at the spud of the water heater - Spuds are welded to the tank and are not repairable. The
heater should be replaced.

• Leakage at the threaded relief valve connection - Remove relief valve and reseal connection.

• Large volume of hot water sporadically discharged from the relief valve – The relief valve relieves
water quickly when actuating on temperature. The only cause of this problem is a malfunctioning
thermostat.

INSULATION BLANKETS

GENERAL The purpose of an insulation blanket is to reduce the standby heat loss encountered with storage tank

heaters. Most modern water heaters have adequate factory installed insulation, the use of an after
market insulation blanket is no longer recommended by most experts. While the use of an external
insulation blanket will not void the warranty, the water heater manufacturer explicitly disclaims any
liability for problems associated with the use of insulation blankets. Note: A few local energy codes
may still require the use of insulation blankets on waters heaters. Be sure to follow all installation
instructions, cautions, and warnings for the insulation blanket as well as the cautions and warning
of the water heaters owners manual.

NOTES Should you choose to apply an insulation blanket to this heater, you should follow these instructions.

Failure to follow these instructions can restrict the air fl ow required for proper combustion, resulting
in fi re, asphyxiation, serious personal injury or death.

• Do not cover the outer door, thermostat or temperature & pressure relief valve.

• When installed the insulation blanket will cover important safety and operation labels. Obtain new
warning and instruction labels from the Technical Information Center listed in the owners’ manual.
The replacement labels must be placed on the blanket in the location of the original labels on the
water heater jacket.

• Do not cover the instruction manual. Keep it on the side of the water heater or nearby for future
reference.

• Do not apply insulation to the top of the water heater, as this will interfere with safe operation of
the draft hood.

• Do not allow insulation to come within 2” of the rear air duct of the water heater to prevent blockage
of combustion air fl ow to the burner. The combustion air openings in the rear air duct of the water
heater must NOT be obstructed.

• Inspect the insulation blanket frequently to make certain it does not sag, thereby obstructing
combustion air fl ow.

35

PROBLEM POSSIBLE CAUSE(S) CORRECTIVE ACTION

BURNER FLAME TOO

HIGH

FLAME BURNS AT

ORIFICE

INSUFFICIENT HOT

WATER

WATER IS TOO HOT

SLOW HOT WATER

RECOVERY

DRIP FROM RELIEF

VALVE

GAS CONTROL/

THERMOSTAT FAILS TO

SHUT OFF

SMELLY WATER

CONDENSATION

COMBUSTION ODORS

TROUBLESHOTING CHART

Insuffi cient secondary air

1.
Orifi ce too large

2.

Low gas pressure

1.
Defective gas control

2.
(thermostat)

Low gas pressure

1.
Orifi ce too small

2.
Thermostat set too low

3.
Gas control error codes

4.
Sediment or lime in tank

5.
Water heater too small

6.
Wrong piping connections

7.
Leaking faucets

8.
Wasted hot water

9.
Long runs of exposed piping

10.
Hot water piping in outside

11.
wall

Thermostat is too high

1.
Defective gas control

2.
(thermostat)

Insuffi cient secondary air

1.
Low gas pressure

2.
Orifi ce too small

3.
Thermostat set too low

4.
Heater too small

5.
Wrong piping connection

6.
Wasted hot water

7.
Flue clogged

8.

Pressure build-up

1.
Heater stacking

2.
Closed water system

3.
Improperly seated valve

4.

Defective gas control

1. Replace gas control (thermostat)1.
(thermostat)

Sulfi des in water supply

1.
Bacteria in water supply

2.

Filling the new water heater for

1.
the fi rst time
Moisture from the products of

2.
combustion
Water dripping from blower

3.
assembly
Undersized water heater

4.

Insuffi cient secondary air

1.
Flue clogged

2.
Heater installed in a confi ned

3.
area
House too tight

4.

Provide ventilation to water heater

1.
Replace with correct orifi ce

2.

Check with gas utility company

1.
Replace gas control (thermostat)

2.

Check with gas utility company

1.
Replace with correct orifi ce

2.
Turn temperature knob to higher setting

3.
Refer to gas control error code in the Installation

4.
and Operating Manual
Drain/fl ush-provide water treatment if needed

5.
Install adequate heater

6.
Correct piping: dip tube must be in cold inlet

7.
Repair faucets

8.
Advise customer

9.
Insulate piping

10.
Insulate piping

11.

Turn temperature knob to lower setting

1.
Replace the gas control (thermostat)

2.

Provide ventilation to water heater. Check fl ue

1.
way, fl ue baffl e and burner
Check with gas utility company

2.
Replace with correct orifi ce

3.
Turn temperature knob to higher setting

4.
Install adequate heater

5.
Correct piping-dip tube must be in cold inlet

6.
Advise customer

7.
Clean fl ue, locate source and correct

8.

Use a pressure reducing valve and relief valve

1.
Lower the thermostat setting

2.
See “Thermal Expansion” Section in the

3.
Manual
Check Relief valve for proper operation (Do Not

4.
plug T&P valve)

See “Smelly water” section in the Manual

1.
See “Smelly water” section in the Manual

2.

Normal operation: the condensation should

1.
disappear after heater warms up
Normal operation: the condensation should

2.
disappear in time
Provide drip “TEE” to the horizontal section of

3.
exhaust vent close to blower assembly
Install adequate heater

4.

Provide fresh air ventilation to the water heater

1.
Clean, locate source and correct

2.
Provide fresh air ventilation to the water heater

3.
Provide fresh air ventilation to the water heater

4.

36

PROBLEM POSSIBLE CAUSE(S) CORRECTIVE ACTION

SMOKING AND CARBON

FORMATION

UNABLE TO LIGHT THE

BURNER

SIZZLING, RUMBLING

NOISE

WATER LEAKAGE

BLOWER WILL NOT

START

BLOWER RUNS

CONTINUOUSLY

HOT SURFACE IGNITER

NOT GLOWING

FOLLOWING WARM-UP

PERIOD

VENT PIPE TOO HOT

(ABOVE 170°F)

Insuffi cient secondary air

1.
Low gas pressure

2.
Orifi ce too large

3.
Flue clogged

4.
Defective gas control

5.
(thermostat)
Heater installed in a confi ned

6.
area

Air in gas line

1.
Pressure switch

2.
Blocked exhaust

3.
Wire connection

4.
Defective gas control

5.
(thermostat)

Scale and sediment

1.
Condensation dripping on

2.
burner

Condensation

1.
Dripping Temperature &

2.
Pressure Relief Valve
Thermostat does not shut-off

3.
Drain valve dripping/leaking

4.
Tank Leak

5.

No power to unit

1.
Thermostat set too low

2.
Defective air pressure switch

3.
Defective blower

4.
Disconnected or loose wire

5.
Control locked out

6.

Air pressure switch not closing

1.
due to insuffi cient draft – check for:
a. Vent piping blocked
b. Piping length too long
c. Clogged/dirty blower
Disconnected, torn or blocked

2.
pressure switch hose from
air pressure switch to blower
housing
Defective pressure switch

3.
High limit switch open due to

4.
excessive vent temperature or
defective switch

Defective hot surface igniter

1.
Defective gas control

2.
(thermostat)

Blower does not run when

1.
heater fi red
Not enough dilution air to mix

2.
with fl ue gases
Air in room too hot for mixing

3.
with fl ue gases
Wrong burner orifi ce

4.

Provide ventilation to water heater. Check fl ue

1.
way, fl ue baffl e and burner
Check with gas utility company

2.
Replace with correct orifi ce

3.
Clean, locate source and correct

4.
Replace gas control (thermostat)

5.
Provide fresh air ventilation

6.

Purge the air from gas line

1.
Check the pressure switch, make sure the

2.
pressure switch hose is not kinked
Check vent pipe for blockage

3.
Check wire connections

4.
Replace the gas control (thermostat)

5.

Drain/fl ush-provide water treatment if needed

1.
See “Strange sounds” section in the Manual

2.

See “Condensate” section in the Manual

1.
See “Temperature & Pressure Relief Valve”

2.
section in the Manual
Check the Thermostat

3.
Back fl ush to clean out sediment, replace if

4.
necessary.
See “Leakage Checkpoints” section

5.

Plug in power cord, check fuses and/or supply

1.
voltage
Turn temperature knob to higher setting

2.
Replace air pressure switch

3.
Replace blower

4.
Repair and reconnect wires

5.
Reset – determine cause of lockout

6.

1.

Determine cause of insuffi cient draft. Check
draft with manometer at pressure switch
(Refer to Table 1 in the Manual for minimum
acceptable draft setting)
a. Remove blockage
b. Reduce vent length/increase vent size
c. Clean blower wheel

2.

Reconnect or replace pressure switch hose

3.

Replace defective pressure switch

4.

Determine cause of overheating check for:
overfi ring, insuffi

cient air supply, high ambient
air temperature (once high limit switch activated,
must be replaced)

Replace igniter

1.
Replace gas control (thermostat)

2.

Refer to “BLOWER WILL NOT START”

1.
problem
Proper air circulation must be provided for

2.
combustion and dilution of fl ue temp
Room air to be used for dilution with combustion

3.
products in fl ue should be less than 90°F
Install correct orifi ce

4.

37

GAS CONTROL LED STATUS CODES

IGNITION STATE AND TIMING

LED Flash Sequence Control Status

Short fl ash
once every four
seconds

“Heartbeat”,
alternates bright/dim

One Flash,
three second pause

Two Flash,
three second pause

Three Flash,
three second pause

Four Flash,
three second pause

Five Flash,
three second pause

Six-One Flash,
three second pause

Six-Two Flash,
three second pause

Six-Three Flash,
three second pause

Six-Four Flash, three
second pause

Seven Flash,
three second pause

Eight-One Flash,
three second pause

Eight-Two Flash,
three second pause

Eight-Three Flash,
three second pause

Eight-Four Flash,
three second pause

IDLE (no call for heat,
no fault conditions)

Call For Heat
(no fault conditions)

Low Flame Signal
(control continues to operate)

Pressure Switch Failed
Closed

Pressure Switch Failed Open

TCO Limit Lockout

Flame Out Of Sequence

Soft Lockout
– Retry Limit

- Failed TFI

Soft Lockout

- Recycle Limit

- PS/Limit opened

Soft Lockout

- Recycle Limit

- Flame Lost

Soft Lockout

- Flame out of Sequence
Sensed

Flammable Vapor Sensor
Lockout

FVS Fault Detected

Temperature Sensor Fault
Detected

Electronics Fault Detected

Valve Fault Detected

IGNITION STATE TIMING

Pre-purge

5 seconds (NG models)

15 seconds (LP models)

HSI Warmup 10 seconds

Ignition Activation
Period (IAP)

Flame Recognition
Period (FRP)

3.5 seconds maximum

0.5 second

Trial For Ignition IAP + FRP

Flame Stabilization
Period

Not Applicable

Inter-purge 30 seconds

Flame Failure
Response Time

2 seconds max
(@ 1uA fl ame current)

Post-purge 30 seconds

PS Prove Period 2 minutes

PS Fault Delay
(failed open/closed)

2 minutes

Soft Lockout 20 minutes

TCO Limit Lockout

Flammable Vapor
Sensor Lockout

Hardware Fault
Lockout

Indefi nite (follow defi ned
procedure to restart)

Indefi nite (follow defi ned
procedure to restart)

Indefi nite (clear fault to restart
in 15 seconds or less)

38

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

39