Bradford White URG2PV75H N Series User manual

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Manual 238-51562-00B 1/19
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
URG2PV75H*N
ULG2PV75H76*N
(*) Denotes Warranty Years
Ultra Low NOx Residential & Light Duty
Commercial Gas
Power Vent 75 Gallon Models
SERVICE
MANUAL
Power Vent 75 Gallon Models

2
The Bradford White
2
UPV75 Series
Through-The-Wall Gas Water Heaters
Table of Contents
Page UPV75 Service Procedure
Introduction ................................................................................................................................4 ---
How to Use This Manual..........................................................................................................5 ---
Tools Required for Service.......................................................................................................5 ---
Specifications .............................................................................................................................6 ---
Control Timings.........................................................................................................................8 ---
Sequence of Operation ..............................................................................................................9 ---
Troubleshooting.........................................................................................................................13 ---
Burner Operation Inspection, Cleaning & Replacement .......................................................15 I
Pilot Inspection, Testing & Replacement................................................................................17 II
Pressure Switch Testing & Replacement ................................................................................19 III
Blower Testing & Replacement...............................................................................................21 IV
Blower Temperature Switch Testing & Replacement ...........................................................23 V
Gas Control Testing & Replacement.......................................................................................25 VI
Simulated Resistive Device Testing and Replacement..........................................................28 VII
Safety Circuit Voltage Trace ....................................................................................................29 VIII
115 VAC Circuit Trace .............................................................................................................30 IX
Diptube Inspection & Replacement.........................................................................................31 X
Anode Inspection & Replacement ...........................................................................................32 XI
Flue Baffle Inspection & Replacement....................................................................................33 XII
Inner Door Removal, Inspection & Replacement ..................................................................34 XIII
Glossary of Terms .....................................................................................................................37 ---
Parts List .....................................................................................................................................38 ---

3
UPV75 Series
3
WARNING: If the information in these
instructions is not followed exactly, a fire or
explosion may result causing property damage,
personal injury, or death.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable,
combustible, or corrosive vapors and liquids in the
vicinity of this or any other appliance.
IMPORTANT
Before proceeding, please inspect the
water heater and its components for
possible damage. DO NOT install any
water heater with damaged
components. If damage is evident
then please contact the supplier where
the water heater was purchased or the
manufacturer listed on the rating plate
for replacement parts.
WHAT TO DO IF YOU SMELL GAS!
xDo not try to light any appliance.
xDo not touch any electrical switch; do not use any
phone in your building.
xImmediately call your gas supplier from a neighbor's phone.
Follow the gas supplier's instructions.
xIf you cannot reach your gas supplier, call the fire
department.
Installation and service must be performed by a qualified
installer, service agency or the gas supplier.
DANGER
Do not store or use gasoline or other flammable,
combustible, or corrosive vapors and liquids in
the vicinity of this or any other appliance.
WARNING
DO NOT ATTEMPT TO LIGHT ANY GAS APPLIANCE IF YOU ARE
NOT CERTAIN OF THE FOLLOWING:
xLiquefied petroleum gases/propane gas and natural gas
have an odorant added by the gas supplier that aids in the
detection of the gas.
xMost people recognize this odor as a “sulfur” or “rotten egg”
smell.
xOther conditions, such as “odorant fade” can cause the
odorant to diminish in intensity, or “fade”, and not be as
readily detectable.
xIf you have a diminished sense of smell, or are in any way
unsure of the presence of gas, immediately contact your gas
supplier from a neighbor’s telephone.
Gas detectors are available. Contact your gas supplier, or plumbing
professional, for more information.
WARNING
FAILURE TO INSTALL AND MAINTAIN A NEW, LISTED ¾” X ¾”
TEMPERATURE AND PRESSURE RELIEF VALVE WILL RELEASE
THE MANUFACTURER FROM ANY CLAIM THAT MIGHT RESULT
FROM EXCESSIVE TEMPERATURE AND PRESSURES.
CAUTION
Turn off or disconnect the electrical power supply to the water heater
before servicing. Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dangerous operation.
Verify proper operation after servicing.
WARNING
Water heaters are heat producing appliances. To avoid damage
or injury, do not store materials against the water heater or vent-
air intake system. Use proper care to avoid unnecessary contact
(especially by children) with the water heater and vent-air intake
components. UNDER NO CIRCUMSTANCES MUST
FLAMMABLE MATERIALS, SUCH AS GASOLINE OR PAINT
THINNER BE USED OR STORED IN THE VICINITY OF THIS
WATER HEATER, VENT-AIR INTAKE SYSTEM OR IN ANY
LOCATION FROM WHICH FUMES COULD REACH THE
WATER HEATER OR VENT-AIR INTAKE SYSTEM
WARNING
Hydrogen gas can be produced in an operating water heater that
has not had water drawn from the tank for a long period of time
(generally two weeks or more). Hydrogen gas is extremely
flammable. To prevent the possibility of injury under these
conditions, we recommend the hot water faucet to be open for
several minutes at the kitchen sink before you use any electrical
appliance which is connected to the hot water system. If
hydrogen is present, there will be an unusual sound such as air
escaping through the pipes as hot water begins to flow. Do not
smoke or have open flame near the faucet at the time it is open.
CAUTION
If sweat fittings are to be used DO NOT apply heat to the nipples
on top of the water heater. Sweat the tubing to the adapter
before fitting the adapter to the water connections. It is
imperative that heat is not applied to the nipples containing a
plastic liner.

4
The Bradford White
4
Introduction
The new Bradford White URG2PV75H and ULG2PV75H water heaters are designed to provide reliable
performance with enhanced standard features. New design features include reliable spark to pilot ignition
system, enhanced diagnostics, simplified servicing, significantly quieter operation, additional vent lengths,
and Bradford White Defender Safety System®(not available on all models).
Spark to Pilot Ignition System - employing the spark to pilot ignition system promotes reliable and consistent
pilot and main burner ignitions to provide hot water on demand.
Integrated Immersion Thermostat/Gas Control Valve with LED - was developed for ease of troubleshooting
by providing simple diagnostic codes to pinpoint an installation or component performance issue.
Powerful Blower - will eliminate problems with difficult venting situations.
Quieter and Cooler Blower Operation - blower noise is significantly reduced for both interior and exterior
environments. Cooler operation increases blower life by reducing bearing wear and noise.
Rugged Wiring Connections - receptacle type connections promote error free wiring.
Increased Vent Lengths - increased venting performance is achieved while maintaining Energy Factor &
FHR (not applicable on all models) performance.
The URG2PV75H and ULG2PV75H water heater uses a combustion system where flue gases are combined
with dilution air to reduce the flue gas temperature in the blower. The diluted flue gases are evacuated to the
exterior through low temperature vent materials. The gas control maintains water temperature, ignition
sequence and regulates gas flow. A safety circuit consisting of a pressure switch and blower temperature
switch verifies proper conditions exist for safe and reliable operation. If a situation outside of normal
operating parameters exists, the gas control diagnostic LED will flash a code to positively identify an
operational issue.
This service manual is designed to facilitate problem diagnosis and enhance service efficiency.
Please read the service manual completely before attempting service on this new series of power vent
models.

5
How to Use This Manual
UPV75 Series
5
How to Use This Manual
It is intended for this manual to be used by qualified service personnel for the primary purpose of
troubleshooting and repair of the Bradford White UPV Series water heaters. Understanding the sequence of
operation section of this manual will contribute greatly to troubleshooting the water heater.
The Honeywell WV4462A Electronic Gas Control will display status codes in the event of abnormal
operation. Status codes are listed in the troubleshooting chart beginning on page 13 of this service manual.
The troubleshooting chart will also indicate the probable cause for the status code and direct the service
professional to a service procedure to properly diagnose the abnormal operation.
In some difficult to diagnose conditions, it may be necessary to isolate the heater from the vent system to
determine the problem.
Contact the Bradford White technical support group immediately if diagnosis cannot be made using the
methods described in this service manual.
Tools Required for Service
Manometer:
Multi-Meter:
Electronic Probes:
Thermometer:
Water Pressure Gage:
Various Hand Tools:
A liquid “U” tube type or a digital (magnahelic) type can be used. This
device is used to measure gas and/or air pressure and vacuum.
A digital type is strongly recommended. This device is used to measure
electrical values. The meter you select must have the capability to
measure volts AC, volts DC, Amps, micro-amps and ohms.
In some cases, standard multi-meter probes will damage or simply not be
effective to obtain certain voltage and ohm readings. It will be necessary to
have special electronic “pin” type multi-meter probes. These probes are
available at most electronic wholesale outlets.
Used to measure water temperature. An accurate thermometer is
recommended.
Used to measure water supply pressure. Also used to determine tank
pressure by adapting to the drain valve of the heater.
Pipe wrench, channel locks, open end wrenches (3/8”, 7/16”, 1/2”), 12”
crescent wrench, allen wrench set, screw drivers (common & Phillip’s), 1/4”
nut driver, pliers (common & needle nose), socket set, side cutters, wire
cutters, wire strippers, wire crimpers, torpedo level, small shop vac, step
ladder, flashlight and 5 gallon pail.

6
Specifications
UPV75 Series
6
Power supply Dedicated 115 VAC, 60 Hz, 15A.
Gas Supply Pipe Minimum 1/2” NPT (schedule 40 black iron pipe recommended).
Approved Gas
Type Natural Gas, unit must match gas type supplied.
Gas Pressure 6.0” W.C. min. for Natural Gas, 14.0” W.C. maximum.
Venting System Power vent through the wall or vertical through the roof.
Approved Vent
Materials PVC, CPVC or ABS.
Minimum
Clearance for
Servicing
18” from top, 24” from front, 4” sides and rear.
Water Supply
Pressure
150 PSI maximum allowable working pressure. Check local codes for supply
pressure.
Gas Control
ECO Limit Residential 188°F (87°C), Commercial 199°F (93°C).
Residential
Temperature Set
Point Range
60°F (16°C) to 160°F (71°C) (approximate temperatures).
Commercial
Temperature Set
Point Range
80°F (27°C) to 180°F (82°C) (approximate temperatures).
Blower
Temperature
Switch
Normally closed, opens @ 155°F (68°C), auto reset @ approximately 135°F (57°C).
Pressure Switch Normally open, closes on vacuum increase @ -1.25” W.C.;
Opens on vacuum decrease @ -1.22” W.C.
Blower 115 VAC, 60 Hz, 3.1 amps, 3000 RPM.

7
Specifications
UPV75 Series
7
Vent Tables
Venting Specifications for:
URG2PV75H
ULG2PV75H
3" Diameter (7.6 cm) PVC Vent Connector Lengths
Terminating # of
Elbows
Maximum Straight
Length ft. (m)
Minimum Straight
Length ft. (m)
Through the Wall 145 (13.7) 2 (.6)
Through the Wall 240 (12.2) 2 (.6)
Through the Wall 335 (10.7) 2 (.6)
Through the Wall 430 (9.2) 2 (.6)
Through the Roof 050 (15.2) 7 (2.1)
Through the Roof 145 (13.7) 7 (2.1)
Through the Roof 240 (12.2) 7 (2.1)
Through the Roof 335 (10.7) 7 (2.1)
4" Diameter (10.2 cm) PVC Vent Connector Lengths
Terminating # of
Elbows
Maximum Straight
Length ft. (m)
Minimum Straight
Length ft. (m)
Through the Wall 1175 (53.3) 10 (3.1)
Through the Wall 2170 (51.8) 10 (3.1)
Through the Wall 3165 (50.3) 10 (3.1)
Through the Wall 4160 (48.8) 10 (3.1)
Through the Wall 5155 (47.2) 12 (3.6)
Through the Roof 0180 (54.9) 15 (4.6)
Through the Roof 1175 (53.3) 15 (4.6)
Through the Roof 2170 (51.8) 15 (4.6)
Through the Roof 3165 (50.3) 15 (4.6)
Through the Roof 4160 (48.8) 15 (4.6)

8
Specifications
UPV75 Series
8
Control Timings
Ignition State Timing
Pre-purge 15 seconds
Trial for Ignition 90 seconds
Flame Stabilization Period 3 seconds
Inter-purge 15 seconds
Flame Failure Response Time 1.5 seconds (2 second. maximum; 1 second
minimum.)
Post-purge 15 Seconds
PS Fault Delay (failed open/close) Retry after 2 minutes
Soft Lockout Retry after 5 minutes
ECO Limit Lockout Indefinite (see page 26)
Verify Resistive Delay Retry after 2 minutes (repeats 5 times)
Flammable Vapor Sensor/Simulated Resistive Load
Lockout Indefinite (cycle power to restart)
Hardware Status Lockout Indefinite (self clears if fault clears for at least 15
seconds)

9
Sequence of Operation
UPV75 Series
9
Power Up Sequence
1. Start Up.
Upon power up, the control runs a safe-start check with a typical start-up delay of 5
seconds.
2. Simulative Resistive Device.
To assure no outputs are energized if the “Simulated Resistive Device” is out of
range, the control will test the “Simulated Resistive Device” for proper operating
range. If the “Simulative Resistive Device” is out of range, the control LED
immediately flashes 7 times with 3 second pause.
Normal Heating Sequence
1. Thermostat calls for heat.
Prior to energizing blower, gas control checks safety circuit to ensure the circuit is
open. Normal switch positions in the safety circuit are as follows:
a) Pressure switch normally open.
b) Blower temperature switch normally closed.
If the safety circuit is closed, the control waits 4 seconds, gas control LED
flashes 2 times with 3 second pause. Gas control waits 2 minutes then,
blower runs for 30 seconds. This cycle repeats until safety circuit opens.
2. Blower energizes.
3. Pressure switch proves blower/vent system operation.
If the pressure switch does not close within 30 seconds, the control LED flashes 3
times with 3 second pause. The blower runs for 30 seconds every 2 minutes trying
to get the pressure switch or blower temperature switch to close. This cycle repeats
as long as there is a call for heat.
4. Blower pre-purge period (2 seconds).
5. Trial for pilot ignition (90 seconds).
a. The gas control lights the pilot by activating spark igniter and gas flow to pilot
burner.
b. If flame is not sensed within 90 seconds, igniter and gas flow are
deactivated, blower will post purge and control LED flashes 6 times with 3
second pause.
6. Main burner ignition.
After pilot flame is sensed, gas control activates main valve for main burner ignition.
The gas control will ignore flame and pressure switch signals for 3 seconds allowing
for main burner to stabilize.

10
Sequence of Operation
UPV75 Series
10
Normal Heating Sequence (cont.)
7. Steady state operation.
During steady state operation, the control monitors:
Temperature sensor-when set point temperature is satisfied, gas valve is shut
down and blower will post purge for 15 seconds. Control LED flashes a short flash
once every 4 seconds (idle) status code.
Pressure switch / blower temperature switch-if either switch opens, pilot valve
and main valve shut down. The blower continues to run for 30 seconds attempting
to close the circuit. The control LED flashes 3 times with 3 second pause.
Flame sensor-if flame is lost, pilot & main valves are shut down, blower runs for 15
seconds. Control attempts to re-light pilot 4 times. If unsuccessful, blower is shut
down and control proceeds to 5 minute lockout. Control re-attempts to light pilot
starting at normal heating sequence #2.
8. Thermostat satisfies. (Control LED flashing once every 4 seconds).
9. Burner off.
10.Blower post purges (15 seconds).
Abnormal Operation
1. Simulated Resistive Device Fault:
a. If the resistance is greater than 70,000 Ohms-the gas control immediately
turns off all outputs. Control waits and monitors resistance for 30 seconds.
If the resistance is greater than 65,000 ohms after 30 seconds, the gas
control proceeds to verify resistive delay for 2 minutes and flashes 7 times
then once with a three second pause. This process is repeated 5 times until
the control either returns to normal operation or proceeds to flammable vapor
lockout.
b. If the resistance is below 3000 Ohms-The gas control immediately turns
off all outputs and proceeds to flash 8 times then once with three second
pause. The status self clears if the resistance returns to normal range for at
least 15 seconds.
2. Temperature sensor Fault:
a. Temperature sensor detected open circuit–The gas control immediately
turns off all outputs and proceeds to flash 8 times then, 3 times with 3
second pause. The status self clears if the fault clears for at least 15
seconds.
b. Temperature sensor not reading the same temperature within ±5.5°F –
The gas control immediately turns off all outputs and proceeds to flash 8

11
Sequence of Operation
UPV75 Series
11
Abnormal Operation (cont.)
times, then 3 times twice with 3 second pause. The status self clears if the
fault clears for at least 15 seconds.
c. Water temperature in excess of ECO (energy cut out) limit -The gas
control immediately turns off pilot & main valves and proceeds to flash 4
times with 3 second pause. Blower continues to run until gas control is reset.
To reset control, rotate knob of temperature control to the minimum setting
for at least 6 seconds before returning to desired temperature setting.
3. Pressure Switch/Blower Temperature Fault:
a. Pressure switch closed at start of call for heat-the gas control waits 4
seconds then, proceeds to flash 2 times with 3 second pause. The control
waits 2 minutes and then turns on blower for 30 seconds. The blower turns
off after 30 seconds and the control waits for pressure switch to open. Any
time the pressure switch opens, the blower turns on (or stays on) and the
control proceeds to wait for pressure switch to close.
b. Pressure switch or blower temperature switch failed to close-the gas
control runs the blower for 30 seconds waiting for the pressure switch and/or
blower temperature switch to close. If either switch does not close in 30
seconds, the blower turns off and the control flashes 3 times with 3 second
pause. The gas control waits 2 minutes before turning on the blower for
another 30 seconds to see the circuit close. This cycle repeats as long as
there is a call for heat or until the circuit closes.
c. Pressure switch or blower temperature switch opens during burner
operation-the gas control turns off the pilot and main valve, runs blower for
15 seconds (inter-purge) waiting for pressure switch and/or blower
temperature switch to close. If either switch fails to close, the control
proceeds as described in 3b above, if the circuit closes again by the end of
the inter-purge, the recycle counter is incremented, if the recycle count has
not reached its limit (4), another trial for ignition begins. If the recycle count
has been reached, the gas control turns off the blower and flashes 6 times
then, 2 times with 3 second pause. The gas control waits 5 minutes before
repeating ignition sequence.
4. Trial for Ignition Fault:
a. Pressure switch opens during trial-the gas control turns off igniter and
pilot valve. The gas control proceeds as described in 3b above. If the
pressure switch closes within 30 seconds the gas control will continue with
trial for ignition starting at blower pre-purge.
b. Flame not sensed-the gas control energizes the spark igniter attempting to
light the pilot and prove flame. If flame is not sensed within 90 seconds, the
igniter turns off, the pilot valve is closed and the gas control runs the blower
through post purge and flashes 6 times then, once with 3 second pause.
The control waits 5 minutes before repeating the ignition sequence.

12
Sequence of Operation
UPV75 Series
12
Abnormal Operation (cont.)
5. Flame sensing fault:
a. Flame lost during run-the gas control turns off pilot and main valves, runs
blower for 15 seconds (inter-purge). The gas control increments the recycle
count, if the recycle count has not reached its limit (4), another trial for
ignition begins. If the recycle count has been reached, the gas control turns
off the blower and flashes 6 times then, 3 times with 3 second pause. The
gas control waits 5 minutes before repeating the ignition sequence.
b. Flame sensed out of sequence-the gas control only looks for pilot flame
when the blower is running. If flame is present when the pilot valve is not
open, the gas control proceeds to wait for flame loss and flashes 5 times with
3 second pause. This continues until flame is lost. Once the flame signal is
lost, the control flashes 6 times then, 4 times with 3 second pause. The
control waits 5 minutes before repeating the ignition sequence.

13
Troubleshooting
UPV75 Series
13
Observe green LED indicator on
electronic gas control. Status flash
codes are displayed with a three second
pause before repeating. Check and
repair the system as noted in the
troubleshooting table below.
LED Status Control Status Probable Cause Service
Procedure
None, control
LED not on or
flashing
No electrical
power
Control power switch in “OFF” position.
Supply voltage interrupted. Turn power on
Short flash,
once every four
seconds
Stand-by mode,
waiting for call for
heat (no fault).
Temperature demand is satisfied
Normal operation.
Adjust thermostat to
temp level.
“Heartbeat”
alternates
bright/dim
Thermostat
calling
for heat (no
fault).
Tank temperature below set point of
thermostat.
Normal operation.
Adjust thermostat to
temp level.
Short flash once
per second
Weak pilot signal
on last call for
heat.
1. Unstable pilot.
2. Pilot tube block or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at gas valve.
Page 18
Two flash, three
second pause
Pressure switch
not working-
closed position.
1. Pressure switch tubing kinked or blocked.
2. Blocked pressure tap on switch or blower.
3. Faulty pressure switch.
Page 19
Three flash,
three second
pause
Pressure switch
or blower temp.
switch not
working -open
position.
1. Vent blockage or improper vent
configuration.
2. Pressure switch tubing kinked or blocked.
3. Faulty pressure switch.
4. Blower not spinning up to speed.
5. Blower temp or exhaust temp too high.
6. Faulty blower temperature switch.
1. Check vent or vent
tables.
2 & 3 Page 19
4. Page 21
5 & 6 Page 23
Four flash, three
second pause
Excessive tank
temperature.
System must be
reset.
1. Temperature sensor out of calibration.
2. Faulty gas control.
3. Plumbing leak.
1 & 2. Replace gas
control, page 27
Five flash, three
second pause
Undesired-false
pilot flame
present.
1. Pilot valve stuck in open position. Replace gas control,
page 27

14
Troubleshooting
UPV75 Series
14
LED Status Control Status Probable Cause Service
Procedure
Six-one flash,
three second
pause
Failed to light pilot.
System auto resets.
1. Unstable pilot.
2. Pilot tube blocked or restricted.
3. Oxidation build up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at the gas valve.
Page 18
Six-two flash,
three second
pause
Pressure switch or
blower temp switch
opened during
burner operation.
System auto resets.
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Faulty pressure switch.
4. Vent termination being affected by wind.
5. Blower not spinning up to speed.
6. Blower temp or exhaust temp too high.
7. Faulty blower temperature switch.
1. Check vent or vent
tables.
2 & 3 Page 19
4. Refer to venting
section of
installation manual
5. Page 21
6 & 7. Page 23
Six-three
flash, three
second pause
Pilot flame
extinguished.
System auto resets.
1. Unstable pilot.
2. Pilot tube blocked or restricted.
3. Oxidation builds up on pilot electrode.
4. Wire damage to pilot assembly or bad
connection at gas valve.
5. Insufficient combustion air.
6. Gas pressure is out of specification.
1-4. Page 18
5. Refer to installation
manual
6. Page 25
Six-four flash,
three second
pause
Undesired-false
pilot flame sensed.
System auto resets.
Pilot valve stuck in open position. Replace gas control,
page 27
Seven flash,
three second
pause
Simulated resistive
device fault
detected.
Simulative resistance device out of specification. Page 28
Eight-one
flash, three
second pause
Simulated resistive
device out of
specification.
Simulative resistive device out of specification. Page 28
Eight-two
flash, three
second pause
Temperature
Sensor fault.
1. Damage to temperature sensor wire.
2. Temperature sensor resistance out of range.
Replace gas control,
page 27
Eight-three
flash, three
second pause
Gas valve
electronics fault
detected.
1. Control needs to be reset.
2. Control is wet or physically damaged.
1. Interrupt power
supply
2. Replace gas control,
page 27
Eight-four
flash, three
second pause
Gas valve fault
detected.
1. Control needs to be reset.
2. Control is wet or physically damaged.
1. Interrupt power
supply
2. Replace gas control,
page 27

15
UPV75 SERVICE PROCEDURE I
Burner Operation Inspection,
Cleaning and Replacement
UPV75 Series
15
Burner Inspection
At periodic intervals (every 6 months) a visual inspection should be made of the pilot and main
burner for proper operation and to assure no debris is accumulating.
Pilot flame should be stable, some causes for an unstable pilot flame are:
a) Water heater vent is less than the allowable vent length.
b) Gas pressure is out of specification.
c) Pilot flame not fully engulfing spark/flame sensor.
Main burner should light smoothly from pilot and burn with a
blue flame with a minimum of yellow tips. Main burner must
be free from any debris accumulation that may affect burner
operation.
Burner Cleaning
Step 1. Position the gas control power
switch to the “OFF” position and
unplug the heater from the wall
outlet.
Step 2. Turn off gas supply to the water
heater.
Step 3. Remove outer jacket door.
Step 4. Disconnect pilot tube (7/16”
wrench) and feedline (¾”
wrench) from gas control.
Step 5. Disconnect igniter/flame sensor
wire from gas control.
Step 6. Remove the (4) ¼” hex drive
screws holding the right side
inner door in place.
Step 7. Remove the (4) ¼” hex drive
screws holding the left side
burner door in place.
Step 8. Remove burner assembly
from combustion chamber.

16
UPV75 SERVICE PROCEDURE I
Burner Operation Inspection,
Cleaning and Replacement
UPV75 Series
16
Burner Cleaning (cont.)
Step 9. Remove manifold mount from burner
inner door by removing (2) ¼” hex
drive screws.
Step 10. Use a stiff brush, compressed air
and/or a vacuum to remove any
debris build up from the manifold
mount.
Step 11. Remove (4) ¼” hex drive screws from
main burner feedline mounting
brackets. Remove brackets from
orifices by hand by turning
counterclockwise.
Step 12. Remove main burner orifices from
feedline (1/2” wrench) inspect orifice,
clean or replace if necessary.
Step 13. Thoroughly inspect burner screen and
burner venturis and remove any loose
debris accumulation. Inspect burner
screen for any openings larger than
the normal screen openings.
Step 14. Reassemble burner and reinstall into
water heater per service procedure XIII
on page 34. Restore gas supply and
check for gas leaks.
Step 15. To resume operation, follow the
instruction located on the lighting
instruction label or the lighting
instruction located in the installation
and operation manual.

17
UPV75 SERVICE PROCEDURE II
Pilot Inspection, Testing and Replacement
UPV75 Series
17
Pilot Inspection, Testing and Replacement
Step 1. Position the gas control power switch
to the “OFF” position and unplug the
heater from the wall outlet.
Step 2. Turn off gas supply to the water
heater.
Step 3. Remove outer jacket door.
Step 4. Disconnect pilot tube (7/16” wrench)
and feedline (¾” wrench) from gas
control.
Step 5. Disconnect igniter/flame sensor wire
from gas control.
Step 6. Remove the (4) ¼” hex drive screws
holding the right side inner door in
place.
Step 7. Remove the (4) ¼” hex drive screws
holding the left side burner door in
place.
Step 8. Remove burner assembly from
combustion chamber.
Step 9. Remove pilot assembly from the
burner assembly (¼” nut driver).
Step 10. Visually inspect igniter/flame sense
wire for damage. Replace pilot if
damage is found.
Step 11. With a multi-meter set to ohms setting,
check continuity through igniter/flame
sense wire. Replace pilot if no
continuity.
Step 12. Visually inspect igniter/flame sense
electrode for deterioration. Replace
pilot as necessary. Electrode should
not be in contact with pilot hood, if so,
carefully adjust electrode to a gap
distance of 3/32” (.09) from pilot hood.

UPV75 SERVICE PROCEDURE II
Pilot Inspection, Testing and Replacement
UPV75 Series
18
Pilot Inspection, Testing and Replacement (cont.)
Step 13.Visually inspect
igniter/flame sense
electrode for oxidation
build up. Carefully clean
any oxidation using very
fine emery cloth.
Step 14.Remove pilot assembly
from the burner
assembly (¼” nut driver).
Step 15.Visually inspect
igniter/flame sense wire
for damage. Replace
pilot if damage is found.
Step 16.With a multi-meter set to ohms setting, check continuity through igniter/flame
sense wire. Replace pilot if no continuity.
Step 17.Visually inspect igniter/flame sense electrode for deterioration. Replace pilot
as necessary. Electrode should not be in contact with pilot hood, if so,
carefully adjust electrode to a gap of distance of 3/32” (.09) from pilot hood.
Step 18.Visually inspect pilot tubing for kinks or cracks. If damage is found, replace
pilot.
Step 19.Inspect pilot tubing and pilot orifice for blockage:
a. Remove ferrule nut from bottom of pilot assembly (7/16” wrench).
b. Remove pilot tube and pilot orifice.
c. Inspect pilot tubing and pilot orifice for blockage. Clean or replace as
necessary.
Step 20.Reassemble pilot and install on burner. Reinstall burner assembly to water
heater. Restore gas supply and check for gas leaks.
Step 21.To resume operation, follow the instruction located on the lighting instruction
label or the lighting instruction located in the installation and operation manual
18

19
UPV75 SERVICE PROCEDURE III
Pressure Switch Testing and Replacement
UPV75 Series
19
Pressure Switch Testing
Step 1. Position power switch on gas
control to the “OFF” position.
Step 2. Remove the three screws (Phillip’s screw driver) from control access cover
on blower assembly and remove cover (see photo 1).
Step 3. Carefully remove pressure switch from blower housing (see photo 2).
WARNING
115 volt potential exposure.
Use caution to avoid personal injury.

20
UPV75 SERVICE PROCEDURE III
Pressure Switch Testing and Replacement
UPV75 Series
20
Pressure Switch Replacement
Step 1. Position gas control power
switch to “OFF” position.
Step 2. Remove the three screws (Phillip’s
screw driver) from control access cover
on blower assembly and remove cover
(see photo 3).
Step 3. Remove pressure switch from blower housing by removing the two T10 screws
(see photo 4a). If it does not have 2 screws, carefully remove it from the housing
(see photo 4b).
Step 4. Disconnect tubing from pressure switch (see photo 5).
Step 5. Disconnect yellow wires from pressure switch (see photo 6).
Step 6. Reconnect yellow wires from step 5 to new pressure switch.
Step 7. Reconnect tubing to new pressure switch.
Step 8. Carefully position pressure switch into blower housing (see photo 4b).
Step 9. Position gas control power switch to “ON” position and verify proper heater
operation.
Step 10. Replace control access cover from step 2.
‘WARNING
115 volt potential exposure. Use
caution to avoid personal injury.