Bradford White UPV75 Series User manual

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Manual 238-53991-00A 05/22
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
URG2PV75H76*N19
ULG2PV75H76*N19
(*) Denotes Warranty Years
UPV75 Series Ultra Low NOx
Through-The-Wall Gas Water Heaters
SERVICE
MANUAL

2
The Bradford White
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......................................................................................................12 ---
Burner Operation Inspection, Cleaning & Replacement.......................................14 I
Pilot Inspection, Testing & Replacement...............................................................16 II
Pressure Switch Testing & Replacement..............................................................18 III
Blower Testing & Replacement .............................................................................20 IV
Replacement Wire Harness Installation ................................................................22 V
Blower Temperature Switch Testing & Replacement...........................................24 VI
Gas Control Testing & Replacement.....................................................................26 VII
Simulative Resistance Device Testing ..................................................................29 VIII
Safety Circuit Voltage Trace ..................................................................................30 IX
115 VAC Circuit Trace ...........................................................................................31 X
Diptube Inspection & Replacement .......................................................................32 XI
Anode Inspection & Replacement.........................................................................33 XII
Flue Baffle Inspection & Replacement ..................................................................34 XIII
Inner Door/Gasket Removal, Inspection & Replacement.....................................35 XIV
Glossary of Terms..................................................................................................38 ---
Parts List and Diagram...........................................................................................39 ---
Notes.......................................................................................................................40 ---
2

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UPV75 Series
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
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.
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.
WARNING
DO NOT ATTEMPT TO LIGHT ANY GAS
APPLIANCE IF YOU ARE NOT CERTAIN OF
THE FOLLOWING:
• Liquefied petroleum gases/propane gas and
natural gas have an odorant added by the gas
supplier that aids in the detection of the gas.
• Most people recognize this odor as a “sulfur” or
“rotten egg” smell.
• Other conditions, such as “odorant fade” can
cause the odorant to diminish in intensity, or
“fade”, and not be as readily detectable.
• If 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.
WARNING
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.
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.
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!
•DO NOT try to light any appliance.
•DO NOT touch any electrical switch; DO NOT use
any phone in your building.
•Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's
instructions.
•If you cannot reach your gas supplier, call the fire
department.
Installation and service must be performed by a qualified
installer, service agency or the gas supplier.
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.
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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 - 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.
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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 12 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: 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.
Multi-Meter: 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.
Electronic Probes: 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.
Thermometer: Used to measure water temperature. An accurate thermometer is recommended.
Water Pressure Gauge: Used to measure water supply pressure. Also used to determine tank
pressure by adapting to the drain valve of the heater.
Various Hand Tools: Pipe wrench, channel locks, open end wrenches (3/8”, 7/16”, 1/2”), 12”
crescent wrench, Allen wrench set, screwdrivers (common & Phillips & T20 Torx), 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.
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UPV75 Series
Specifications
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 U(L,R)G2PV75H Models: Normally open, closes on vacuum increase
@ -0.96" W.C.; Opens on vacuum decrease @ -.91" W.C.
Blower 115 VAC, 60 Hz, 3.3 amps, 3300 RPM.
HIGH ALTITUDE INSTALLATIONS
This appliance has been certified for installations up to 10,100 ft above sea level without modification. Installations greater
than 10,100 ft above sea level are not intended. Unauthorized modifications may result in unsafe operation.
WARNING: In order to assure the safe and efficient performance of the water heater, it is necessary to follow the vent
connector length rules shown below. Failure to adhere to these rules can result in the unsafe operation of the appliance.
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UPV75 Series
Vent Tables
Venting Specifications for:
URG2PV75H*N19, ULG2PV75H*N19
VENT CONNECTOR LENGTHS
FOR 3 in (7.6 cm) DIAMETER VENT PIPE
Terminating
# of
Elbows
(excl. vent
terminals)
Minimum
Straight
Length
ft (m)
Maximum
Straight
Length
ft (m)
Installation elevation above
sea level ft (m)
0-10100
(0-3079)
0-2000
(0-610)
2001-
5400
(610-1646)
5401-7800
(1646-2378)
7801-10100
(2378-3079)
Through the Wall
1
2 (0.6)
70 (21.3)
60 (18.3)
30 (9.1)
20 (6.1)
Through the Wall
2
2 (0.6)
65 (19.8)
55 (16.8)
25 (7.6)
15 (4.6)
Through the Wall
3
2 (0.6)
60 (18.2)
50 (15.2)
20 (6.1)
10 (3.0)
Through the Wall
4
2 (0.6)
55 (16.7)
45 (13.7)
15 (4.6)
5(1.5)
Through the Roof
0
7 (2.1)
75 (22.8)
65 (19.8)
35 (10.7)
25 (7.6)
Through the Roof
1
7 (2.1)
70 (21.3)
60 (18.3)
30 (9.1)
20 (6.1)
Through the Roof
2
7 (2.1)
65 (19.8)
55 (16.8)
25 (7.6)
15 (4.6)
Through the Roof
3
7 (2.1)
60 (18.2)
50 (15.2)
20 (6.1)
10 (3.0)
VENT CONNECTOR LENGTHS
FOR 4 in (10.2 cm) DIAMETER VENT PIPE
Terminating
# of
Elbows
(excl. vent
terminals)
Minimum
Straight
Length
ft (m)
Maximum
Straight
Length
ft (m)
Elevation of installation
above sea level ft (m)
0-10100
(0-3079)
0-5400
(0-1646)
5400-7800
(1646-2378)
7801-10100
(2378-3079)
Through the Wall
1
10 (3.1)
175 (53.3)
160 (48.8)
105 (32.0)
Through the Wall
2
10 (3.1)
170 (51.8)
155 (47.2)
100 (30.5)
Through the Wall
3
10 (3.1)
165 (50.3)
150 (47.7)
95 (29.0)
Through the Wall
4
10 (3.1)
160 (48.8)
145 (44.2)
90 (27.4)
Through the Wall
5
10 (3.1)
155 (47.2)
140 (42.7)
85 (25.9)
Through the Roof
0
15 (4.6)
180 (54.9)
165 (50.3)
110 (33.5)
Through the Roof
1
15 (4.6)
175 (53.3)
160 (48.8)
105 (32.0)
Through the Roof
2
15 (4.6)
170 (51.8)
155 (47.2)
100 (30.5)
Through the Roof
3
15 (4.6)
165 (50.3)
150 (45.7)
95 (29.0)
Through the Roof
4
15 (4.6)
160 (48.8)
145 (44.2)
90 (27.4)
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UPV75 Series
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 27)
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)
Wiring Diagram
8

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UPV75 Series - Sequence of Operations
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.
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).
9

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UPV75 Series - Sequence of Operations
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 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.
10