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.

11
UDV SERVICE PROCEDURE II
Pilot Testing, Cleaning & Replacement
UDV Series
11
Remove Burner to Gain Access to the Pilot
Step 1. Position the gas control knob in
the “OFF” position.
Step 2. Turn off the gas supply to the
water heater.
Step 3. Remove the outer jacket door
and inner doors per service
procedure VI on page 16.
Step 4. Disconnect the igniter wire from
the gas control. Disconnect the
red and white pilot wires from the
gas control.
Step 5. Disconnect the pilot tube (7/16”
wrench) from the gas control.
Step 6. Disconnect the main feedline
(3/4” wrench) from gas control.
Step 7. Remove the burner assembly
from the combustion chamber.

12
UDV SERVICE PROCEDURE II
Pilot Testing, Cleaning & Replacement
UDV Series
12
Pilot Inspection, Testing and Replacement
Step 1. Remove the pilot assembly from the burner
(1/4” nut driver).
Step 2. Visually inspect the igniter wire for
damage. Replace pilot if damaged.
Electrode should not be in contact with the
pilot hood.
Step 3. With a multi-meter set to ohms setting,
check continuity through igniter wire.
Replace pilot if no continuity.
Step 4. Visually inspect igniter electrode for
oxidation build up. Carefully clean any
oxidation using a very fine emery cloth.
Step 5. Visually inspect the pilot tubing for kinks or
cracks. If damage is found, replace the
pilot assembly.
Step 6. Inspect the pilot tubing and the pilot orifice
for blockage:
a. Remove the ferrule nut from the bottom of
the pilot assembly (7/16” wrench).
b. Remove the pilot tube and pilot orifice.
c. Inspect the pilot tubing and orifice for
blockage. Clean or replace as necessary.
Step 7. Reassemble pilot and install onto the
burner.
Step 8. Reinstall the burner assembly into the
water heater.
Step 9. Restore the gas supply and check for any
gas leaks.
Step 10. To resume operation, follow the
instructions located on the lighting
instruction label or the lighting instructions
located in the installation and operation
manual.

13
UDV SERVICE PROCEDURE III
Gas Control Testing and Replacement
UDV Series
13
Line Pressure
The gas control is designed for a maximum line pressure of 14.0” W.C. and a minimum
line pressure of 1.0” W.C. over the water heater’s rated manifold pressure (check rating
plate). Line pressure must be checked with the main burner on and off to assure proper
readings.
Manifold Pressure Testing
(this procedure presumes a maximum
line pressure of 14.0” w.c.)
Step 1. Position the gas control knob in the “OFF”
position.
Step 2. Remove the pressure tap plug and install
a 1/8” NPT pipe, coupling & pressure tap.
Step 3. Connect a manometer to the pressure
tap.
Step 4. Follow instructions located on the lighting
instruction label and proceed to light the
main burner and observe the manometer
readings.
Step 5. Proper operating range for Natural Gas is
5.0” ±0.5” w.c.
Step 6. If pressure is within the range specified in
the previous step, set the Gas Control
knob to the “OFF” position, remove
manometer and pressure tap, and replace
pressure tap plug.
Step 7. Check for gas leaks prior to placing water
instructions located on the lighting label,
or the lighting instructions located in the
installation and operation manual.
Step 8. If the gas pressure is outside of the
specification noted above, refer to the
“Gas Control Testing and Replacement”
to replace gas control on page 12.

14
UDV SERVICE PROCEDURE III
Gas Control Testing and Replacement
UDV Series
14
ECO (Energy Cut Out)
The Honeywell gas control is designed with an ECO device that will reset.
To reset the gas control after a status code (4), turn the gas control knob to the “OFF”
position and wait a minimum of (5) minutes before relighting following the instructions
located on the lighting instruction label or the lighting instructions located in the
installation and operation manual.
Determine Water Temperature Inside Tank
Step 1. Position the gas control knob to the “OFF” position.
Step 2. Draw approximately 4 gallons of water from the drain valve into a container
and discard.
Step 3. Compare the measured water temperature with the setting on the gas
control. In most instances, they should not differ by more than approx.
10°F.
WARNING
Stored water may be HOT WHEN PERFORMING THE FOLLOWING STEPS IN
THIS PROCEDURE. Take necessary precaution to prevent personal injury.

15
UDV SERVICE PROCEDURE III
Gas Control Testing and Replacement
UDV Series
15
Gas Control Removal from Water Heater
Step 1. Position the gas control knob in the “OFF” position.
Step 2. Drain the heater to a point below the gas control level.
Step 3. Turn off the gas supply to the water heater and disconnect
gas piping from the gas control.
Step 4. Disconnect the igniter wire and the red and white pilot wires
from the gas control.
Step 5. Remove the outer jacket burner access door.
Step 6. Disconnect the pilot tube (7/16” wrench) from the gas
control.
Step 7. Disconnect the main feedline (3/4” wrench) from gas control.
Step 8. Remove gas control from water heater by rotating counter
clockwise. DO NOT use a wrench on the gas control body,
damage to the Gas Control may occur. If necessary, use a
length of ½” NPT pipe threaded into the gas inlet of gas
control.
Step 9. Install new gas control into water heater by rotating
clockwise. DO NOT use a wrench on the gas control body,
damage to the Gas Control may occur. If necessary, use a
length of ½” NPT pipe threaded into the gas inlet of the gas
control.
Step 10.Reattach the main burner feedline, pilot tube and pilot
wires. Reattach igniter wire.
Step 11.Reconnect gas supply and check for leaks.
Step 12.To resume operation, follow the instructions located on the
lighting instruction label or the lighting instructions located
in the installation and operation manual.

16
UDV SERVICE PROCEDURE IV
Thermopile Testing and Replacement
UDV Series
16
Closed Circuit Thermopile Testing
Closed circuit thermopile testing is the preferred method for testing the thermopile.
Step 1. Following the lighting instruction
label on the heater, proceed to light
the pilot and allow to operate for
three minutes. If the pilot will not
stay lit, hold the pilot button (rotate
the gas control knob to the pilot
position, push and hold in) during
this test.
Step 2. Using a multimeter capable of
measuring millivolts, place one lead
of the multimeter on the left side of
the wire harness and place the
second lead of the multimeter on
the right side of the wire harness.
Step 3. If meter reads 300 millivolts or higher, the thermopile is OK. If reading is
below 300 millivolts, replace the pilot assembly per service procedure II on
pages 9 & 10.
Open Circuit Thermopile Testing
Step 1. Disconnect the red and white pilot wires from the gas control.
Step 2. Using a multimeter capable of measuring millivolts, connect one lead to the
red thermopile wire and one lead to the white thermopile wire.
Step 3. Following the lighting instruction label on the heater,
proceed to light the pilot and allow the heater to
operate for three minutes. It will be necessary to
hold the gas control knob
down in the “PILOT” position
continuously throughout this
test. A reading over 400
millivolts indicates a good
thermopile output.
Step 4. A reading under 400 millivolts
indicates a bad thermopile, replace
the pilot assembly per service procedure II on pages 9 & 10.

17
UDV SERVICE PROCEDURE V
Igniter, Electrode Testing and Replacement
UDV Series
17
Igniter, Electrode Testing and
Replacement
Step 1. Remove the outer jacket door.
Step 2. Repeatedly depress the igniter button while
viewing the pilot through the flame viewing
window. If a spark is present, the circuit is
OK. If there is no spark, proceed to step 3.
Step 3. Remove the white wire from the gas
control’s igniter wire. Hold the igniter lead
from the gas control to an unpainted
surface such as the feedline and depress
the igniter. If there is a spark, the igniter is
OK. Otherwise, the igniter is not
functioning and the pilot assembly must be
replaced. See service procedure II on
pages 9 & 10.

UDV SERVICE PROCEDURE VI
Inner Door Removal and Replacement
UDV Series
18
Inner Door Removal Procedure
Step 1. Position the gas control knob in the “OFF” position.
Step 2. Remove the outer jacket burner access door.
Step 3. Remove the wire clip from the feedline if present.
Step 4. Remove (2) ¼” hex drive screws from the right side inner door.
Step 5. Remove (2) ¼” drive screws from the flange section of the inner door.
Step 6. Remove (3) ¼” drive screws from the left side inner door.
Step 7. Remove the inner doors.
Step 8. Fully inspect inner door gaskets for the following:
-Tears -Other imperfections that will inhibit proper seal
-Missing Material -Gasket adhesion to inner door
-Cracks -Material left on combustion chamber (around opening)
-Dirt or debris
If the gasket is not effected by any of the above, gasket replacement is not required. If
replacement is required, proceed to Inner Door Gasket Replacement Procedure.
Inner Door Gasket Replacement Procedure
Step 9. After inspection of inner door as noted in step 8, completely remove gasket and
adhesive residue from right and left side inner doors as needed.
WARNING
If the information in these instructions is not followed exactly, a
fire or explosion may result causing property damage, personal
injury or death.
18

19
UDV SERVICE PROCEDURE VI
Inner Door Removal and Replacement
UDV Series
19
Inner Door Gasket Replacement Procedure (cont.)
Step 10. Use RTV sealant (recommended bead size 1/8”) to secure the inner door gasket to
the inner door sections (right & left). Refer to the illustrations on the next page for
proper application. Note the overlap configuration in the flange area of the inner
door. Set the flange section first, this will help to achieve the proper overlap position.
Installation of Inner Door with Gasket
Step 11. Clean any residual gasket residue or other debris
from combustion chamber surface before
installing the inner door/gasket assembly.
Step 12. Place the left side inner door and burner
assembly into position first. Using the (3) ¼” hex
drive screws from step 6, secure left side inner
door in place. DO NOT OVER TIGHTEN
SCREWS
Step 13. Position pilot tube and igniter/sensor
wire against left side inner door flange
gasket.
Step 14. Firmly place right side inner door flange
against the left side inner door flange
and secure with (2) ¼” hex drive screws
from step 5. DO NOT OVER TIGHTEN
SCREWS.
WARNING
Stripped fastener connections
may allow for seal breach of
inner door. A seal breach may
result in a fire or explosion
causing property damage,
personal injury or death. Do
not over tighten screws in
steps 12, 14 and 15.

20
UDV SERVICE PROCEDURE VI
Inner Door Removal and Replacement
UDV Series
20
Installation of Inner Door with Gasket (cont.)
Step 15. Align right side inner door to combustion chamber and verify the fastener
holes of the combustion chamber are aligned with right side inner door
slotted opening. Verify seal integrity around combustion opening.
Secure right side inner door using ¼” hex drive screws from step 4. DO
NOT OVER TIGHTEN SCREWS. Verify both left and right sides of inner
door are properly positioned and sealed against the combustion
chamber.
Step 16. Replace outer jacket burner access door.
Step 17. To resume operation, follow the instructions located on the lighting
instruction label or the lighting instructions located in the installation and
operation manual.