resideo VR8405 User manual

INSTALLATION INSTRUCTIONS
69-0815-02
VR8405 High Capacity Direct Ignition
Combination Gas Control
APPLICATION
This high capacity direct ignition combination gas
control is used in gas-fired appliances with capacities
up to 500 feet3/hour at 1 inch wc pressure drop [14.2
meters3/hour at 0.25 kPa] on natural gas. This entire
gas control consists of two valves assembled in parallel
on a die-cast manifold to provide high capacity. Each
valve includes a manual valve and two automatic
operators. A nonremovable electrical harness connects
both valves. Do not alter or remove this harness. Two
pigtail leads (with 1/4-inch quick connects) provide for
field connection. Gas controls are available for natural
gas and LP; they are not convertible from one gas to
another. Bushings are available to reduce the inlet and
outlet of the entire gas control.
Models are available with slow-opening (VR8405H),
standard (VR8405M) and step-opening (VR8405P)
regulators.
Valves have fixed pressure regulation and are not
adjustable. It is recommended that an appliance shutoff
valve be installed upstream of the VR8405.
BODY PATTERN: Straight-through body pattern.
INLET/OUTLET SIZES: 3/4 x 3/4 inch, 3/4 x 1 inch,
1 x 1 inch.
aCapacity based on 1000 Btu/feet3, 0.64 specific gravity natural gas at 1 inch wc pressure drop [37.3 MJ/meter3,
0.64 specific gravity natural gas at 0.25 kPa pressure drop].
Use conversion factors in Table 2 to convert capacities
for other gases.
Electrical Ratings:
Voltage and Frequency: 24 Vac, 60 Hz. (50/60 Hz models
available on request.)
Current Draw: 1.4A.
Thermostat Heat Anticipator Setting: 1.4A.
Temperature Rating:
VR8405H: -0° F to 175° F [-18° C to +79° C].
VR8405M,P: -40° F to +175° F [-40° C to +79° C].
Accessory:
Part no. 390427H 3/4 in. x 1 in. Bushing.
Approvals:
American Gas Association design certificate: L2025009.
Canadian Gas Association design certificate: L2025009.
Underwriters Laboratories Inc.: MH8191
INSTALLATION
When Installing This Product…
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a haz-
ardous condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable
for your application.
3. The installer must be a trained, experienced ser-
vice technician.
4. After installation is complete, use these instruc-
tions to check out product operation.
Table 1. Capacity.
Size (Inlet x Outlet) (in.)
Capacity (at 1 inch wc
pressure dropa)
Minimum
Regulated Capacity
Maximum
Regulated Capacity
3/4 x 3/4 400 feet3/hour
[11.3 meter3/hour]
200 feet3/hour
[5.7 meter3/hour]
575 feet3/hour
[16.3 meter3/hour]
3/4 x 1 450 feet3/hour
[12.7 meter3/hour]
200 feet3/hour
[5.7 meter3/hour]
625 feet3/hour
[17.7 meter3/hour]
1 x 1 500 feet3/hour
[14.1 meter3/hour]
200 feet3/hour
[5.7 meter3/hour]
720 feet3/hour
[20.3 meter3/hour]
Table 2. Gas Capacity Conversion Factors.
Gas Specific Gravity
Multiply Listed
Capacity By
Manufactured 0.60 0.516
Mixed 0.70 0.765
Propane 1.53 1.62

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
69-0815—02 2
WARNING
Fire or explosion hazard. Can cause property
damage, severe injury, or death.
Follow these warnings exactly:
1. Disconnect power supply before wiring to
prevent electrical shock or equipment damage.
2. To avoid dangerous accumulation of fuel gas,
turn off gas supply at appliance service valve
before starting installation, and perform the
Gas Leak Test after completion of installation.
3. Always install sediment trap in gas supply line
to prevent contamination of gas control.
4. Do not force the gas control knobs. Use only
your hand to turn the gas control knobs. Never
use any tools. If the gas control knobs will not
operate by hand, call a qualified service
technician to replace the entire gas control.
Force or attempted repair can result in fire or
explosion.
5. Replace entire VR8405 when doing a product
replacement. Do not replace individual valve
components.
6. For complete device shutoff, both gas control
knobs must be in the OFF position. For
complete appliance shutoff, turn off the
upstream appliance valve and disconnect the
power supply.
7. Use the wiring harness for connecting the
entire gas control to the ignition control
module. Do not remove the harness or modify
the wires in the harness.
CAUTION
Never apply a jumper across or short the valve
leadwires. This can burn out the heat anticipator
in the thermostat or damage the electronic direct
ignition (DI) module.
IMPORTANT
This entire gas control is shipped with protec-
tive seals over inlet and outlet tappings. Do not
remove seals until ready to connect piping.
Follow the appliance manufacturer instructions if
available; otherwise, use the instructions provided below.
Install Bushings on Entire Gas Control
1. Remove seals over gas control inlet or outlet.
2. Apply moderate amount of good quality pipe com-
pound to bushing, leaving two end threads bare. On
an LP gas installation, use compound resistant to
LP gas. See Fig. 2. Do not use Teflon tape.
3. Insert bushing in entire gas control and thread pipe
carefully into bushing until tight.
Choose Gas Control Location
Locate the gas control in the appliance vestibule on the
gas manifold. In replacement applications, locate the
entire gas control in the same location as the old gas
control.
Do not locate the entire gas control where it can be
affected by steam cleaning, high humidity, dripping water,
corrosive chemicals, dust or grease accumulation, or
excessive heat. To safeguard proper operation, follow
these guidelines:
• Locate entire gas control in a well-ventilated area.
• Mount entire gas control high enough above the
cabinet bottom to avoid exposure to flooding or
splashing water.
• Make sure the ambient temperature does not exceed
the ambient temperature ratings for the entire gas
control.
• Cover entire gas control when appliance is cleaned
with water, steam, or chemicals or to avoid dust and
grease accumulation.
• Avoid locating gas control where exposure to
corrosive chemical fumes or dripping water is
possible.
Install Appliance Shutoff Valve
It is recommended that an appliance shutoff valve be
installed upstream of the VR8405. Refer to the
instructions provided by the valve manufacturer.
Install Piping to Gas Control
All piping must comply with local codes and ordinances
or with the National Fuel Gas Code (ANSI Z223.1 NFPA
No. 54), whichever applies. Tubing installation must
comply with approved standards and practices.
1. Use new, properly reamed pipe free from chips. If
tubing is used, make sure the ends are square,
deburred and clean. Make sure all tubing bends are
smooth and without deformation.
2. Run pipe or tubing to the gas control. If tubing is
used, obtain a tube-to-pipe coupling to connect
the tubing to the gas control.
3. Install sediment trap in the supply line to the entire
gas control. See Fig. 1.
Fig. 1. Install sediment trap.
GAS
CONTROL
GAS
CONTROL
HORIZONTAL
DROP
PIPED
GAS
SUPPLY
PIPED
GAS
SUPPLY
3 IN.
(76 MM)
MINIMUM
3 IN.
(76 MM)
MINIMUM
RISER
GAS
CONTROL
TUBING
GAS
SUPPLY
HORIZONTAL
DROP
3 IN.
(76 MM)
MINIMUM
RISER
M3077A
2
1
2
2
1
2
ALL BENDS IN METALLIC TUBING SHOULD BE SMOOTH.
CAUTION: SHUT OFF THE MAIN GAS SUPPLY BEFORE REMOVING
END CAP TO PREVENT GAS FROM FILLING THE WORK AREA. TEST
FOR GAS LEAKAGE WHEN INSTALLATION IS COMPLETE.

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
369-0815—02
Install Gas Control
1. This gas control can be mounted from 0 to 90
degrees in any direction from the vertical position
of the gas control knobs.
2. Mount the gas control so gas flow is in the direc-
tion of the arrows on the bottom of the controls.
3. Thread pipe for insertion into the gas control mani-
fold. Do not thread pipe too far. Manifold distortion
or malfunction can result if the pipe is inserted too
deeply into the gas control. Refer to Table 3.
4. Apply a moderate amount of good quality pipe
compound (do not use Teflon tape) to pipe only,
leaving two end threads bare. On LP installations,
use compound resistant to LP gas. Refer to Fig. 2.
5. Remove seals over gas control inlet and outlet if
necessary.
6. Connect pipe to gas control inlet and outlet. Use a
wrench on the manifold rather than on the gas
control. Refer to Fig. 5 and 6.
Fig. 2. Use moderate amount of pipe compound.
WIRING
Follow the wiring instructions furnished by the appliance
manufacturer, if available, or use the general instructions
provided.
All wiring including insulated quick connect terminals
must comply with applicable electrical codes and
ordinances.
Disconnect power supply before making wiring
connections to prevent electrical shock or equipment
damage.
1. Check the power supply rating on the gas control
and make sure it matches the available supply.
Install transformer, thermostat, and other controls
as required.
2. Connect control circuit to gas control terminals.
See Fig. 3 and 4.
3. Adjust thermostat heat anticipator to 1.4A rating
stamped on gas control.
Fig. 3. VR8405 wiring connections in S87 Direct Ignition
System.
Fig. 4. VR8405 wiring connections in S89C Direct Ignition System.
Table 3. NPT Pipe Thread Length in in.
Pipe
Size
Thread Pipe
This Amount
Maximum Depth Pipe Can
Be Inserted Into Control
3/4 13/16 3/4
11-1/16 1
TWO IMPERFECT
THREADS GAS CONTROL
THREAD PIPE THE AMOUNT
SHOWN IN TABLE FOR
INSERTION INTO GAS CONTROL
APPLY A MODERATE AMOUNT OF
PIPE COMPOUND TO PIPE ONLY
(LEAVE TWO END THREADS BARE).
M8052
PIPE
24V
24V (GND)
S87 CONTROL MODULE
ALARM
VALVE
VALVE
GND
TEMPERATURE
CONTROLLER
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
PROTECTION AS REQUIRED.
ALTERNATE LIMIT CONTROLLER LOCATION.
MAXIMUM IGNITER-SENSOR CABLE LENGTH: 3 ft. [.9 m] OR LESS.
3 A REPLACEABLE FUSE.
ALARM TERMINAL PROVIDED ON SOME MODELS.
M8051
MV
MV
L1
(HOT)
L2
1
2
1
2
3
VR8405
COMBINATION
GAS CONTROL
Q347 IGNITER-SENSOR
BURNER
4
4
5
IGNITER-SENSOR AND
BURNER GROUND
3
5
ALARM, IF USED
QUICK
CONNECTS
24V
24V (GND)
VALVE
VALVE (GND)
L2
HSI
L1
HSI
MV
MV
L1
(HOT)
L2
1
3
2
1
2
3
3
VR8405
COMBINATION
GAS CONTROL
S89/S890 HOT SURFACE
IGNITER CONTROL
HOT SURFACE
IGNITER/SENSOR
Q354 FLAME
SENSOR
LIMIT
CONTROLLER
THERMOSTAT OR
CONTROLLER
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
MAKE SURE L1 AND L2 ARE NOT REVERSED. THIS WOULD PREVENT FLAME DETECTION.
ALTERNATE LIMIT CONTROLLER LOCATION
SEN TERMINAL AND Q354 FLAME SENSOR ON D MODELS ONLY.
SEN
BURNER
GROUND
M8054
QUICK
CONNECTS

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
69-0815—02 4
STARTUP AND CHECKOUT
WARNING
Fire or explosion hazard. Can cause property
damage, severe injury, or death.
1. Do not force the gas control knobs. Use only
your hand to turn the gas control knobs. Never
use any tools.
2. If the gas control knobs will not operate by
hand, call a qualified service technician to
replace the entire gas control.
3. Both knobs must be in the same position for
operation or shutoff.
Gas Control Knobs Settings
The gas control knobs have two settings:
OFF: Prevents main burner gas flow.
ON: Permits gas to flow into the control body. Under
control of the thermostat and direct ignition mod-
ule, gas can flow to the main burner.
NOTE: Gas controls are shipped with the gas control
knobs in the ON position.
Perform Gas Leak Test
WARNING
Fire or explosion hazard. Can cause property
damage, severe injury, or death.
Check for gas leaks with a rich soap and water
solution any time work is done on a gas control.
Gas Leak Test
1. Paint all pipe connections upstream of the gas
control with a rich soap and water solution. Bub-
bles indicate a gas leak.
2. If a gas leak is detected, tighten the pipe connec-
tion.
3. Stand clear while lighting main burner to prevent
injury caused from hidden gas leaks that could
cause flashback in the appliance vestibule. Turn on
the entire gas control and light the main burner as
described below.
4. With the main burner in operation, paint all pipe
joints and gas control inlet and outlet with a rich
soap and water solution.
5. If another gas leak is detected, tighten pipe con-
nections.
6. Replace the part if gas leak cannot be stopped.
Turn On Gas Control
Rotate the gas control knobs counterclockwise to
ON.
Turn On Main Burner
Follow instructions provided by appliance manufacturer
or turn up thermostat to call for heat.
Check Gas Input to Main Burner
CAUTION
1. Do not exceed the input rating stamped on the
appliance nameplate, or manufacturer
recommended burner orifice pressure for the
size orifice(s) used. Make certain the primary
air supply to the main burner is properly
adjusted for complete combustion (refer to the
appliance manufacturer instructions).
2. WHEN CHECKING GAS INPUT BY CLOCKING
THE GAS METER:
• Make sure that the only gas flow through
the meter is that of the appliance being
checked.
• Make certain that other appliances are
turned off with pilot burners extinguished
(or deduct that gas consumption from the
meter reading).
• Convert the flow rate to Btuh as described
in the Gas Controls Handbook, form 70-
2602, and compare to the Btuh input rating
on the appliance nameplate.
Standard-Opening and Slow-Opening
Pressure Regulator
1. The gas control outlet pressure should match the
manifold pressure listed on the appliance name-
plate.
2. With the main burner operating, check the gas con-
trol flow rate using the meter clocking method.
3. If the desired gas flow rate is not as stamped on
the control, check the gas control inlet pressure
using a manometer at the inlet pressure tap. Regu-
lators are fixed. They are not adjustable. If the inlet
pressure is in the normal range (refer to Table 4),
replace the entire gas control. Otherwise, take the
necessary steps to provide proper gas pressure to
the gas control.
NOTE: Factory set outlet pressure is not field adjust-
able.
Step-Opening Pressure Regulator
1. The gas control outlet pressure should match the
manifold pressure listed on the appliance name-
plate.
2. With the main burner operating, check the gas con-
trol flow rate using the meter clocking method.
3. If desired flow rate is not as stamped on the con-
trol, check the inlet pressure using a manometer at
inlet pressure tap or upstream of the gas control.
Regulators are fixed. They are not adjustable. If the
inlet pressure is in the normal range (refer to
Table 4), replace the entire gas control. Otherwise,
take the necessary steps to provide proper gas
pressure to the gas control.
4. Carefully check main burner lightoff at the step
pressure. Make sure the main burner lights
smoothly and without flashback to the orifice and
that all ports remain lit. Cycle the main burner sev-
eral times, allowing at least 30 seconds between
cycles for the regulator to resume the step func-
tion. Repeat after allowing main burner to cool.

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
569-0815—02
Check Safety Shutdown
Performance
WARNING
Fire or explosion hazard. Can cause property
damage, severe injury, or death.
Perform the safety shutdown test any time work
is done on a gas system.
NOTE: Read steps 1 through 7 below before starting,
and compare to the safety shutdown or safety
lockout tests recommended for the direct igni-
tion (DI) module. Where they differ, use the pro-
cedure recommended for the module.
1. Turn off knobs on entire gas control.
2. Set thermostat or controller above room tempera-
ture to call for heat.
3. Watch for ignition spark or glow at hot surface
igniter either immediately or following prepurge.
See DI Module specifications.
4. Time the length of the igniter operation. See DI
Module specifications.
5. After the module locks out, open gas control knobs
and make sure there is no gas flow to the main
burner.
6. Set thermostat below room temperature and wait
one minute.
7. Operate system through one complete cycle to
make sure all controls operate properly.
NOTE: Factory set outlet pressure is not field adjustable.
Fig. 5. Proper use of wrench on gas control manifold.
Table 4. Pressure Regulator Specification Pressures in in. WC [kPa].
Model Type of Gas Nominal Inlet Pressure
Factory Set Outlet Pressure
Step Full Rate
H (Slow-opening) Natural 7.0 [1.7] — 3.0 - 5.0
[0.7 - 1.2]
LP 14.0 [3.9] — 8.0 - 12.0
[2.0 - 3.0]
M (Standard) Natural 7.0 [1.7] — 3.0 - 5.0
[0.7 - 1.2]
LP 14.0 [3.9] — 8.0 - 12.0
[2.0 - 3.0]
P (Step-opening) Natural 7.0 [1.7] 0.7, 0.9, 1.2, 1.7,
[0.17, 0.22, 0.30, 0.42]
3.0 - 5.0
[0.7 - 1.2]
LP 14.0 [3.9] 1.4, 2.5, 4.0, 5.5
[0.35, 0.62, 1.0, 1.4]
8.0 - 12.0
[2.0 - 3.0]
APPLY WRENCH
TO MANIFOLD ONLY
M9368

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
69-0815—02 6
Fig. 6. Top view of gas control.
MAINTENANCE
WARNING
Fire or explosion hazard. Can cause property
damage, severe injury, or death.
Do not disassemble the gas control or either
valve. They contain no replaceable components.
Attempted disassembly or repair can damage the
gas control.
Regular preventive maintenance is important in
applications such as commercial cooking, agricultural
and industrial operations that place a heavy load on
system controls because:
• In many such applications, particularly commercial
cooking, the equipment operates 100,000 to 200,000
cycles per year. Such heavy cycling can wear out the
gas control in one to two years.
• Exposure to water, dirt, chemicals and heat can
damage the gas control and shut down the control
system.
The maintenance program should include regular
checkout of the entire gas control; see Startup and
Checkout section. To check out the control system, see
the appliance manufacturer literature. Maintenance
frequency must be determined individually for each
application. Some considerations are:
•Cycling frequency. Appliances that may cycle 100,000
times annually should be checked monthly.
•Intermittent use. Appliances that are used seasonally
should be checked before shutdown and again before
the next use.
•Consequence of unexpected shutdown. Where the
cost of an unexpected shutdown would be high, the
system should be checked more often.
•Dusty, wet, or corrosive environment. Since these
environments can cause the gas control to deteriorate
more rapidly, the system should be checked more
often.
If the gas controls will be exposed to high ammonia
conditions; e.g., those used in greenhouses or animal
barns, contact your sales representative to request a gas
control with corrosion resistant construction.
The entire gas control should be replaced if:
• It does not perform properly during checkout or
troubleshooting.
• The gas control knobs are hard to turn.
• The gas control is likely to have operated for more
than 200,000 cycles.
SERVICE
WARNING
Fire or explosion hazard. Can cause property
damage, severe injury, or death.
Do not disassemble the gas control or either
valve. They contain no replaceable components.
Attempted disassembly or repair will damage the
gas control.
CAUTION
Do not apply a jumper across or short the valve
leadwires. Doing so can burn out the heat
anticipator in the thermostat or damage the DI
module.
IMPORTANT
Allow 60 seconds after shutdown before re-
energizing step-opening model to assure ligh-
toff at step pressure.
If Main Burner Will not Come on with Call
for Heat
1. Make sure gas control knobs are in the ON posi-
tion.
2. Adjust thermostat several degrees above room
temperature.
3. Using an AC voltmeter, measure voltage across MV
leadwires at the gas valve.
4. If no voltage is present, check control circuit for
proper operation.
5. If 24V is present, replace the entire gas control.
Instructions to the User
For Your Safety, Read Before Lighting
WARNING
If you do not follow the warnings below and the
lighting instructions exactly, a fire or explosion
can result with property damage, personal injury
or loss of life.
Follow these warnings exactly.
1. Before lighting, smell around the appliance for gas.
Be sure to smell next to the floor because LP gas is
heavier than air.
2. IF YOU SMELL GAS:
• Turn off the gas supply at the appliance service
valve. On LP gas systems, turn off gas supply at
the gas tank.
• Do not light any appliances.
• Do not touch electrical switches or use the
phone.
• Leave the building and use a neighbor’s phone
to call your gas supplier.
• If you can not reach your gas supplier, call the
fire department.
3. Do not force the gas control knob. Use only your
hand to push down or turn the gas control knob.
Never use any tools. If the gas control knob will not
operate by hand, call a qualified service technician
to replace the entire gas control. Force or
attempted repair can result in a fire or explosion.
4. Call a qualified service technician to replace the
entire gas control if it has been flooded with water.
INLET
PRESSURE TAPS
M9079
OUTLET
PRESSURE TAPS
OUTLET
INLET
ON
OFF
ON
OFF
GAS
CONTROL KNOBS
WIRING HARNESS

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
769-0815—02
5. Replace the entire gas control in the event of any
physical damage, tampering, bent terminals, miss-
ing or broken parts, stripped threads, or evidence of
exposure to heat.
IMPORTANT
Follow the operating instructions provided by
the manufacturer of your heating appliance. The
information below will be of assistance in a typ-
ical control application, but the specific controls
used and the procedures outlined by the manu-
facturer of your appliance may differ, and
require special instructions.
To Turn on the Appliance
Stop: Read the Warning Above
The lighting sequence of this appliance is automatic. Do
not attempt to manually light the main burner. If the
appliance does not turn on when the thermostat is set
several degrees above room temperature, follow these
instructions:
1. Set the thermostat to its lowest setting to reset the
safety control.
2. Disconnect all electric power to the appliance.
3. Remove the gas control access panel.
4. Turn both of the gas control knobs clockwise
to OFF.
5. Wait five minutes to clear any unburned gas. If you
then smell gas, STOP! Follow step 3 in the Warning
in the Instructions To The User section. If you do
not smell gas, continue with the next step.
6. Turn both of the gas control knobs counterclock-
wise to ON.
7. Replace the gas control access panel.
8. Reconnect all electric power to the appliance.
9. Set the thermostat to the desired setting.
10. If the appliance does not turn on, set the gas con-
trol knobs to OFF, turn off the upstream appliance
valve, and contact a qualified service technician for
assistance.
Turning off the Appliance
VACATION SHUTDOWN: Set the thermostat to the
desired room temperature while you are away.
COMPLETE APPLIANCE SHUTDOWN: Turn both gas
control knobs clockwise to OFF. Do not force. Turn
off the upstream appliance valve and disconnect power
supply. Appliance will be completely shut off.
To resume normal operation, turn on the upstream
appliance valve and connect the power supply; then
follow the procedure above.

VR8405 HIGH CAPACITY DIRECT IGNITION COMBINATION GAS CONTROL
© 2020 Resideo Technologies, Inc. All rights reserved.
This product is manufactured by Resideo Technologies, Inc. and its affiliates.
www.resideo.com
Resideo Technologies, Inc.
1985 Douglas Drive North, Golden Valley, MN 55422
1-800-468-1502
69-0815—02 M.S. Rev. 04-20 | Printed in United States