Bradford White ECO-DEFENDER EURG2DV40S N Series User manual

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Manual 238-51635-00B REV 10/18
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
URG2DV40S*N
URG2DV50S*N
URG2DV50H*N
ULG2DV50H50*N
(*) Denotes Warranty Years
Ultra Low NOx Direct Vent Water Heaters
Flammable Vapor Ignition Resistant
Water Heaters

2
2
UDV Series
Ultra Low NOxDirect Vent Water Heaters
Table of Contents
Page UDV SVC Procedure
Introduction ................................................................................................................................4 ---
How to Use This Manual..........................................................................................................4 ---
Tools Required for Service .......................................................................................................5 ---
Troubleshooting.........................................................................................................................6 ---
Burner Inspection, Cleaning & Replacement .........................................................................9 I
Pilot Testing, Cleaning & Replacement ..................................................................................11 II
Gas Control Testing & Replacement.......................................................................................13 III
Thermopile Testing ...................................................................................................................16 IV
Igniter, Electrode Testing and Replacement ...........................................................................17 V
Inner Door Removal and Replacement ...................................................................................18 VI
Diptube Inspection & Replacement.........................................................................................21 VII
Anode Inspection & Replacement ...........................................................................................22 VIII
Glossary of Terms .....................................................................................................................23 ---
Parts List .....................................................................................................................................24 ---

3
UDV 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.
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
UDV Series
4
Introduction
The new Bradford White UDV water heaters are designed to provide reliable performance with enhanced
standard features. Design features include reliable standing pilot ignition system, enhanced diagnostics,
simplified servicing, certified FVIR technology, and Ultra Low NOxemissions.
The UDV water heaters use a combustion system where combustion air is drawn from the outside of the
building. The gas control maintains water temperature and maintains gas flow. If a situation outside of
the normal operating parameters exists, the gas control diagnostic LED will flash a code to 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 direct vent
water heaters.
How the Safety System Works
During normal operation, most air for combustion is drawn into the water heater though the openings in
the jacket door. This air travels into the burner venturi, mixing the gas jet. This air is then mixed with gas
inside the burner and drawn into 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 the 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. This causes
the thermopile to overheat and shuts down the main pilot and burner. The thermopile powers the
intelligent diagnostic control which is capable of recognizing restricted airflow conditions caused by
severe lint, dust and oil accumulation on the burner screen and arrestor plate. The intelligent diagnostic
control will deactivate the burner and pilot in the unlikely event of restricted airflow.

5
UDV 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 UDV Series water heaters.
The Honeywell WV8840 Gas Control will display status codes in the event of abnormal operation. Status
codes are listed in the troubleshooting chart beginning on page 6 of this service manual. The
troubleshooting chart on page 6 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 vacuum, step ladder, flashlight and 5-gallon pail.

6
DV Series
6
Troubleshooting V1
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 (LED not
on or flashing) Pilot assembly is not lit Gas control is not powered. Light Pilot.
If the pilot will not stay lit
replace pilot assembly. If
problem persists, replace
gas control.
One flash and
three second
pause
1. If setpoint knob is in “PILOT”
position, then pilot flame is
detected. Turn setpoint knob
to desired setting.
2. If the setpoint knob is
already at the desired
setting, the water heater is
satisfied.
1. Gas control is
powered and waiting
for setpoint knob to
be turned to a water
temperature setting.
2. Water heater is
satisfied and
operatin
g
normall
y
.
Normal operation.
Short flash
once per
second
Gas control is calling for heat (no
fault).
Tank temperature
below setpoint of
thermostat.
Normal operation.
LED on
continuously
(solid)
Setpoint knob has been recently
turned to the “OFF”position.
Wait until LED goes out before
attemptin
g
to reli
g
ht.
Setpoint knob was
turned to “OFF”
position.
LED will go out and the
control will function normally
the pilot is lit.
Two flashes
and three
second pause
Weak pilot signal detected.
System will reset when pilot
flame is sufficient.
1. Thermopile failure.
2. Unstable pilot.
3. Pilot tube block or
restricted.
1. See service procedure IV.
2. See service procedure II.
3. See service procedure II.
Three flashes
and three
second pause
Insufficient water heating.
System will reset.
1. Thermal sensor out
of calibration.
2. Faulty gas control.
Replace gas control.

7
UDV Series
7
Troubleshooting V1
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
Four flashes
three second
pause
Excessive tank temperature.
System must be reset.
1. Temperature sensor
out of calibration.
2. Faulty gas control.
Replace gas control
Five flashes
and three
second pause
Temperature sensor fault.
1. Damage to the
temperature sensor.
2. Temperature sensor
resistance out of
range.
Replace gas control
Six flashes
and three
second pause
Water leak detected by
accessory module
Excessive amount of
water in drain pan/water
dam.
1. Check T&P valve.
2. Check all water fittings.
3. Pressurize and leak test
tank.
Seven flashes
and three
second pause
Gas control electronic fault
detected.
1. Control needs to be
reset.
2. Control is wet or
ph
y
sicall
y
dama
g
ed.
1. Reset gas control
2. Replace gas control.
Eight flashes
and three
second pause
Standing pilot remains on while
setpoint knob is in “OFF”
position.
Pilot valve stuck in
open position. Replace gas control

UDV Series
8
Troubleshooting V2
Observe colored 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 (LED no
on or flashing)
Millivolt power is not
present. Light pilot.
Gas valve is functioning
normally. Gas valve is not
powered. Light pilot.
If the pilot will not stay lit
replace pilot assembly. If
problem persists, replace
g
as control.
One flash every
four seconds
(LED green)
Not an error. Indicates pilot
is lit and main burner is off.
You can now turn the know to a
desired setpoint temperature Normal operation.
One flash every
second
(LED green)
Not an error. Indicates main
valve is open and main
burner is lit.
None. Control will automatically
shut main burner off when
water temperature reaches the
setpoint temperature.
Normal operation.
Two flashes
(LED yellow)
Low thermopile voltage;
main valve not turned ON. Check thermopile and its
connections. Check pilot flame.
1. See service procedure
IV.
2. See service procedure II.
3. See service procedure II.
Four flashes
(LED red) Temperature cut-out limit
reached.
Check the valves and the water
temperature sensor. Reduce
the water temperature setpoint.
Thoroughly check
out main valve operation and
water temperature control
before walking away.
Replace gas control
Five flashes
(LED red) Water temperature sensor
failure.
Check water temperature
sensor and its connection for
open circuits, shorts, or
differences in resistance
between the two sensor
elements.
Replace gas control
Six flashes
(LED red)
Tank leakage detected by
accessory module.
Control recovers after receiving
message from accessory
module.
4. Check T&P valve.
5. Check all water fittings.
6. Pressurize and leak test
tank.
Solid ON
(LED red)
Not an error-indicates that
the control is in OFF mode.
None; wait until LED turns off if
you want to restart system.
LED will go out and the
control will function
normally the pilot is lit.
8

9
UDV SERVICE PROCEDURE I
Burner Operation Inspection,
Cleaning and Replacement
UDV Series
9
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
(see burner cleaning procedure below).
Burner Cleaning
Step 1. Position the gas control knob in
the “OFF” position.
Step 2. Turn off the gas supply to the
water heater.
Step 3. Disconnect the igniter wire from
the gas control.
Step 4. Disconnect the red and white
pilot wires from the gas control.
Step 5. Remove the outer jacket door.
Remove the inner doors per
service procedure VI on page 16.
Step 6. Disconnect the pilot tube (7/16”
wrench) from the gas control.
Step 7. Disconnect the main feedline
(3/4” wrench) from the gas
control.
Step 8. Remove the burner assembly
from the combustion chamber.

10
UDV SERVICE PROCEDURE I
Burner Operation Inspection,
Cleaning and Replacement
UDV Series
10
Burner Cleaning (cont.)
Step 9. Thoroughly inspect the burner
surface area and the burner
port area and remove any
loose debris.
Step 10. Unscrew the burner feedline
from the main burner inner
door.
Step 11. Remove the main burner
orifice from the feedline
(1/2” wrench).
Step 12. Inspect the orifice, clean or
replace if necessary.
Step 13. Reassemble the burner and reinstall
into the water heater.
Step 14. Restore the gas supply and check
for any gas leaks.
Step 15. To resume operation, follow the instructions located on the lighting
instruction label or the lighting instructions located in the installation
and operation manual.