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