Bradford White URG1PV40S*N User manual

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Manual 238‐51548‐00A 4/15
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
URG1PV40S*N
URG1PV50S*N
URG2PV40T*N
URG2PV50T*N
URG2PV50H*N
ULG2PV50H56*N
(*) Denotes Warranty Years
Through-The-Wall Gas Water Heaters
UPV Series

2
The Bradford White
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2

UPV Series
Through-The-Wall Gas Water Heaters
Table of Contents
Page PV Service Procedure
Introduction ................................................................................................................................4 ---
How to Use This Manual..........................................................................................................5 ---
Tools Required for Service .......................................................................................................5 ---
Specifications .............................................................................................................................6 ---
Control Timings.........................................................................................................................9 ---
Sequence of Operation ..............................................................................................................10 ---
Troubleshooting.........................................................................................................................14 ---
Burner Inspection, Cleaning & Replacement .........................................................................16 I
Pilot Testing, Cleaning & Replacement ..................................................................................18 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
Flammable Vapor 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
Resettable Thermal Switch, Inspection & Replacement........................................................37 XIV
ScreenLok® Flame Arrestor Cleaning.....................................................................................39 ---
Glossary of Terms .....................................................................................................................40 ---
Parts List .....................................................................................................................................41 ---

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

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Introduction
The new Bradford White URG1PV & URG2PV 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 free wiring.
Increased Vent Lengths - increased venting performance is achieved while maintaining Energy Factor &
FHR (not applicable on all models) performance.
The URG1PV & URG2PV water heaters use 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.
How the Safety System Works
During normal operation, most air for combustion is drawn into the water heater through the openings in the
jacket door. This air travels into the burner venturi, mixing with the gas jet. This air is then mixed with gas
inside the burner and drawn to the burner screen and is efficiently combusted producing Ultra Low NOx
emissions. Additional air is drawn through the openings in the jacket. This air travels down and around the
combustion chamber and enters through holes in the bottom of the corrosion-resistant combustion chamber.
The air then travels up through the oriented flame arrestor plate louvers, where they velocity of the air is
increased and its direction altered. The air then mixes in a normal manner with the combustion products
from the burner.
In the case where trace amounts of flammable vapors are present in the air flowing into the combustion
chamber and burner venturi, the vapors are harmlessly ignited by the burner/pilot flame. If flammable vapors
are in sufficient quantity to prevent normal combustion, the burner and pilot flames are designed to shut
down.
Should the flammable vapors continue to the burner, the flame arrestor plate and burner screen prevent the
flames from traveling backwards and igniting vapors outside of the combustion chamber. The gas control
utilizes a flammable vapor sensor to detect the presence of flammable vapors and shut down if the vapors
achieve a certain level.

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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 14 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.

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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
URG1PV(40,50)S Models: Normally open, closes on vacuum increase @ -.75” W.C.;
Opens on vacuum decrease @ -.72” W.C.
RG2PV(40,50)T: Normally open, closes on vacuum increase @ -.80” W.C.;
Opens on vacuum decrease @ -.77” W.C.
URG2PV50H Models: Normally open, closes on vacuum increase @ -1.40” W.C.;
Opens on vacuum decrease @ -1.37” W.C.
Blower 115 VAC, 60 Hz, 3.1 amps, 3000 RPM.

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Vent Tables
Venting Specifications for:
URG1PV40S, URG2PV40T
URG1PV50S, URG2PV50T
2" Diameter (5.1 cm) Vent Connector Lengths
Terminating # of
Elbows
Maximum Straight
Length ft. (m)
Minimum Straight
Length ft. (m)
Through the Wall 1 45 (13.7) 2 (.6)
Through the Wall 2 40 (12.2) 2 (.6)
Through the Wall 3 35 (10.7) 2 (.6)
Through the Wall 4 30 (9.1) 2 (.6)
Through the Roof 0 50 (15.2) 7 (2.1)
Through the Roof 1 45 (13.7) 7 (2.1)
Through the Roof 2 40 (12.2) 7 (2.1)
Through the Roof 3 35 (10.7) 7 (2.1)
Through the Roof 4 30 (9.2) 7 (2.1)
3" Diameter (7.6 cm) Vent Connector Lengths
Terminating # of
Elbows
Maximum Straight
Length ft. (m)
Minimum Straight
Length ft. (m)
Through the Wall 1 115 (35) 10 (3.1)
Through the Wall 2 110 (33.5) 10 (3.1)
Through the Wall 3 105 (32.0) 10 (3.1)
Through the Wall 4 100 (30.5) 10 (3.1)
Through the Wall 5 95 (29.0) 10 (3.1)
Through the Roof 0 120 (36.6) 15 (4.6)
Through the Roof 1 115 (35) 15 (4.6)
Through the Roof 2 110 (33.5) 15 (4.6)
Through the Roof 3 105 (32.0) 15 (4.6)
Through the Roof 4 100 (30.5) 15 (4.6)

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Vent Tables
Venting Specifications for:
URG2PV50H
ULG2PV50H
3" Diameter (7.6 cm) Vent Connector Lengths
Terminating # of
Elbows
Maximum Straight
Length ft. (m)
Minimum Straight
Length ft. (m)
Through the Wall 1 55 (16.8) 2 (.6)
Through the Wall 2 50 (15.2) 2 (.6)
Through the Wall 3 45 (13.7) 2 (.6)
Through the Wall 4 40 (12.2) 2 (.6)
Through the Roof 0 60 (18.3) 7 (2.1)
Through the Roof 1 55 (16.8) 7 (2.1)
Through the Roof 2 50 (15.2) 7 (2.1)
Through the Roof 3 45 (13.7) 7 (2.1)
4" Diameter (10.2 cm) Vent Connector Lengths
Terminating # of
Elbows
Maximum Straight
Length ft. (m)
Minimum Straight
Length ft. (m)
Through the Wall 1 175 (53.3) 10 (3.1)
Through the Wall 2 170 (51.8) 10 (3.1)
Through the Wall 3 165 (50.3) 10 (3.1)
Through the Wall 4 160 (48.8) 10 (3.1)
Through the Wall 5 155 (47.2) 10 (3.1)
Through the Roof 0 180 (54.9) 15 (4.6)
Through the Roof 1 175 (53.3) 15 (4.6)
Through the Roof 2 170 (51.8) 15 (4.6)
Through the Roof 3 165 (50.3) 15 (4.6)
Through the Roof 4 160 (48.8) 15 (4.6)

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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)

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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. Flammable Vapor.
To assure no outputs are energized if the “Flammable Vapor Sensor” is out of
range, the control will test the “Flammable Vapor Sensor” or “Simulated Resistive
Device” for proper operating range. If the “Flammable Vapor Sensor” or “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.