Chamberlain HD750WF User manual

CONTENTS
Preparation . . . . . . . . . . . . . . . .1-4
Assembly . . . . . . . . . . . . . . . . .5-9
Installation . . . . . . . . . . . . . . 10-27
Adjustments . . . . . . . . . . . . . 28-30
MyQ®Smartphone Control
Get Connected . . . . . . . . . . . . . . 31
Operation . . . . . . . . . . . . . . . 32-36
Maintenance . . . . . . . . . . . . . . . 37
Troubleshooting. . . . . . . . . . . 38-39
Accessories. . . . . . . . . . . . . . . . 40
Warranty. . . . . . . . . . . . . . . . . . 41
Repair Parts . . . . . . . . . . . . . 42-43
The Chamberlain Group, Inc.
845 Larch Avenue
Elmhurst, Illinois 60126-1196
Model HD750WF
FOR RESIDENTIAL USE ONLY
3/4 hps*Belt Drive
Garage Door Opener with
MyQ®Smartphone Control
■ Please read this manual and the enclosed safety materials carefully!
■ Fasten the manual near the garage door after installation.
■The door WILL NOT CLOSE unless the Protector System®is connected and
properly aligned.
■ Periodic checks of the garage door opener are required to ensure safe operation.
■The model number label is located on the left side panel of your garage door
opener.
■This garage door opener is compatible with MyQ®and Security+ 2.0®
accessories.
■DO NOT install on a one-piece door if using devices or features providing
unattended close. Unattended devices and features are to be used ONLY with
sectional doors.
www.chamberlain.com
www.mychamberlain.com
*Horsepower similar (hps) designates that this garage
door opener system meets Chamberlain’s pulling force
specification for a 3/4 horsepower garage door opener.
Write down the MyQ®serial number
located on the garage door opener:

1
Safety Symbol and Signal Word Review
This garage door opener has been designed and tested to offer safe service provided it isinstalled,
operated,maintained and tested in strictaccordance with the instructions and warningscontained in this
manual.
When you see these Safety Symbolsand Signal Wordson the following pages,they will alert you to the
possibility of serious injury or death if you do not comply with the warnings that accompany them. The
hazard may come from something mechanical or from electricshock. Read the warnings carefully.
Mechanical
Electrical
When you see this Signal Word on the following pages,itwill alert you to the possibilityof damage to
your garage door and/or the garage door opener ifyou do not complywith the cautionary statements that
accompany it. Read them carefully.
Unattended Operation
The Timer-to-Close (TTC) feature,the MyQ®Smartphone Control app, and MyQ®Garage Door and
Gate Monitor are examplesof unattended close and are to be used ONLY with sectional doors. Any
device or feature that allows the door to close without being in the line of sightof the door is considered
unattended close.The Timer-to-Close (TTC) feature, the MyQ®Smartphone Control,and anyother
MyQ®devices are to be used ONLY with sectional doors.
Check the Door
To prevent possible SERIOUS INJURY or DEATH:
lALWAYS call a trained door systems technician if garage door binds, sticks, or is out of balance.
An unbalanced garage door may NOT reverse when required.
lNEVER try to loosen, move or adjust garage door, door springs, cables, pulleys, brackets or their
hardware,ALL ofwhich are under EXTREME tension.
lDisable ALL locks and remove ALL ropes connected to garage door BEFORE installation and
operating garage door opener to avoid entanglement.
lDO NOTinstall on a one-piece door ifusing devicesor featuresproviding unattended close.
Unattended devicesand features are to be used ONLY with sectional doors.
To preventdamage to garage door and opener:
lALWAYS disable locks BEFORE installing and operating the opener.
lONLY operate garage door opener at120 V,60 Hzto avoid malfunction and damage.
Before you begin:
1. Disable locks and remove any ropes connected to the garage door.
2. Lift the door halfway up. Release the door. If balanced, it should stay
in place, supported entirely by its springs.
3. Raise and lower the door to checkfor binding or sticking. If your door
binds, sticks, or is out of balance, call a trained door systems
technician.
4. Check the seal on the bottom ofthe door. Any gap between the floor
and the bottomof the door must not exceed 1/4 inch (6 mm).
Otherwise, the safety reversal system may not work properly.
5. The opener should be installed above the center of the door. Ifthere
is a torsion spring or center bearing plate in the way ofthe header
bracket, it may be installed within 4feet (1.2 m) to the leftor right of
the door center. See page11.
Torsion
Spring
Extension
Spring
OR
Preparation

2
Test the Wi-Fi®Signal Strength in your garage
You will need a router with Wi-Fi and a smartphone or other mobile device.Make sure your mobile
device is connected to your Wi-Fi network. Hold your mobile device in the place where your garage door
opener will be installed and checkthe Wi-Fi signal strength.
Wi-Fi signal is weak.
The garage door opener will likely connect to your Wi-Fi
network. If not, try one of the options below.
No Wi-Fi signal. Try one of the following:
• Move your router closer to the garage door opener to
minimize interference from walls and other objects
• Buy a Chamberlain MyQ®Internet Gateway (CIGBU) see page 40
• Buy a Wi-Fi range extender
Check Signal Strength. If you see:
Wi-Fi signal is strong. You’re all set!
Install your new garage door opener.
Visit wifihelp.chamberlain.com for more details
See MyQ®Smartphone Control page 31 to connectyour garage door opener to your Wi-Fi network.
Additional Items You May Need:
Surveyyour garage area to see if you will need any ofthe following items:
l(2) 2X4 Pieces of wood : Maybe used to fasten the header bracketto the structural supports.
Also used to position the garage door opener during installation and for testing the safety
reversing sensors.
lSupport bracket and fastening hardware: Mustbe used if you have a finished ceiling in your
garage.
lExtension brackets (MODEL 041A5281-1) or wood blocks: Depending upon garage
construction, extension brackets or wood blocks may be needed to install the safety reversing
sensor.
lFastening hardware: Alternate floor mounting of the safety reversing sensor will require
hardware not provided.
lDoor reinforcement: Required if you have a lightweight steel, aluminum, fiberglass or glass
panel door.
lRail extension kit: Required if your garage door is more than 7 feet (2.13 m) high.
Tools Needed
3/16
7/16
1/2
5/32
5/16
5/8
9/16
1/4
7/16
Preparation

3
Carton Inventory
Your garage door opener is packaged in one carton which contains the motor unit and all parts
illustrated below.Accessories varydepending on the garage door opener model purchased.Depending
on your model, other accessoriesmay be included with your garage door opener.Instructionsfor these
accessorieswill be attached to the accessoryand are not included in this manual. Save the carton and
packing material until the installation and adjustment is complete. The images throughout this manual
are for reference only and your product may look different.
A. Header bracket
B. Pulley
C. Door bracket
D. Curved door arm
E. Straight door arm
(Packaged inside front rail section)
F. Trolley
NOTE: Be sure to assemble the trolley before sliding onto rail.
G. Emergency release rope and handle
H. Rail (1 front and 4 center sections)
I. Hanging brackets (2)
(Packaged inside the front rail section)
J. Garage door opener (motor unit)
K. Sprocket cover and screws
L. “U” bracket
M. Belt
N. Door control
O. Remote control (2)
P. The Protector System®
Safety reversing sensors with 2 conductor white and white/blackwire attached: Sending Sensor
(1), Receiving Sensor (1), and Safety Sensor Brackets (2)
NOT SHOWN
White and red/white wire
Owner's manual
Hardware
N
A
B
C
H
K
J
O
I
D
E
F
G
L
M
P
Preparation

4
Hardware
Clevis Pin 5/16"x1-1/2"
Ring Fastener (3)
Hex Bolt 5/16"-18x7/8" (4)
Lock Washer
5/16"-18 (5)
Nut
5/16"-18 (6)
Self-Threading Screw
1/4"-14x5/8" (2)
Clevis Pin 5/16"x1"
Clevis Pin 5/16"x1-1/4"
Carriage Bolt
1/4"-20x1/2" (2)
Wing Nut 1/4"-20 (2)
ASSEMBLY INSTALLATION
Screw 6ABx1" (2)
Drywall Anchors (2)
Screw 6-32x1" (2)
DOOR CONTROL
Insulated
Staples
(Not Shown)
Lag Screw 5/16"-9x1-5/8" (4)
Hex Screw
#8x3/8" (3)
(packed with the
sprocket cover)
Bolt
1/4"-20x1-3/4"
Lock Nut
1/4"-20
Bolt
Nut 3/8"
Lock Washer 3/8"
Master Link
Spring
Trolley Nut
Threaded
Shaft
with
Preparation

5
Assembly
STEP 1 Assemble the rail and install the trolley
To prevent INJURY from pinching, keep hands and fingers awayfrom the jointswhile assembling the
rail.
To avoid installation difficulties, do not run the garage door opener until instructed to do so.
The front rail has a cut out “window” at the door end. The rail tab MUST be on top of the rail when
assembled.
1. Remove the straight door arm and hanging bracketpackaged inside the front rail and setaside
for Installation Step 5 and 9. NOTE: To prevent INJURY while unpacking the rail carefully remove
the straight door arm stored within the rail section.
2. Align the rail sections on a flatsurface as shown and slide the tapered ends into the larger ones.
Tabsalong the side will lockinto place.
3. Place the motor unit on packing material to protect the cover, and rest the backend ofthe rail on
top. For convenience,put a support under the front end of the rail.
4. As a temporarystop,insert a screwdriver into the hole in the second rail section from the motor
unit, as shown.
5. Check to be sure there are 4 plastic wear padsinside the inner trolley.If they became loose
during shipping, check all packing material. Snap them back into position as shown.
6. Slide the trolley assemblytoward the screwdriver as shown.
7. Slide the rail onto the “U” bracket,until itreaches all the stops on the top and sides ofthe “U”
bracket.
To garage
door opener
(TO MOTOR UNIT)
Front Rail
Section
(TO DOOR)
“U” Bracket
Outer Trolley
Inner Trolley
Wear Pads
SLIDE TO STOPS
ON TOP AND
SIDES OF
“U” BRACKET
Trolley
Rail Tab

6
Assembly
STEP 2 Fasten the rail to the motor unit
To avoid SERIOUS damage to garage door opener,use ONLY those bolts/fasteners mounted in the
top of the opener.
1. Insert a 1/4"-20x1-3/4" boltinto the cover protection bolthole on the backend ofthe rail as
shown.Tighten securely with a 1/4"-20 locknut.DO NOTovertighten.
2. Remove the bolts from the top ofthe motor unit.
3. Use the carton to supportthe front end of the rail.
4. Place the “U” bracket, flat side down onto the motor unit and align the bracketholes with the bolt
holes.
5. Fasten the “U” bracketwith the previouslyremoved bolts; DO NOT use any power tools. The use
ofpower toolsmay permanently damage the garage door opener.
HARDWARE
Bolt 1/4"-20x1-3/4" Lock Nut 1/4"-20
“U” Bracket
Cover Protection
Bolt Hole
Bolt 1/4"-20x1-3/4"
Lock Nut 1/4"-20
Bolts (Mounted in the
garage door opener)

7
Assembly
STEP 3 Install the idler pulley
1. Lay the belt beside the rail, asshown.Grasp the end with the hooked trolley connector and pass
approximately12" (30 cm) ofbelt through the window. Keep the ribbed side toward the rail, and
allow it to hang until Assembly Step 4.
2. Remove the tape from the idler pulley.The inside center should be pre-greased. Ifdry,regrease
to ensure proper operation.
3. Place the idler pulley into the window as shown.
4. Insert the idler boltfrom the top through the rail and pulley. Tighten with a 3/8" lockwasher and
nut underneath the rail until the lock washer is compressed.
5. Rotate the pulleyto be sure it spins freely.
6. Locate the rail tab.The rail tab is between the idler bolt and the trolley in the front rail section. Use
a flathead screwdriver and lift the rail tab until the tab is vertical (90º).
HARDWARE
Bolt Nut 3/8"
Lock Washer 3/8"
Rail
Trolley Connector
Bolt
Lock Washer 3/8"
Nut 3/8"
Rail Tab
CORRECT
INCORRECT
Rail Tab
Idler Pulley
Grease Inside Pulley

8
Assembly
STEP 4 Install the belt
1. Pull the belt around the idler pulleyand toward the trolley.The ribbed side must contact the
pulley.
2. Hook the trolley connector into the retaining slot on the trolley as shown (Figure 1).
3. With the trolley againstthe screwdriver, dispense the remainder of the belt along the rail
lengthtoward the motor unit and around the sprocket(Figure 2).The sprocketteeth must engage
the belt.
4. Check to make sure the belt isnot twisted. Connect the trolley threaded shaft with the master link
(Figure 3).
lPush pins of master link bar through holes in end of belt and trolley threaded shaft.
lPush master link cap over pins and past pin notches.
lSlide the closed end of the clip-on spring over one of the pins. Push the open end ofthe
clip-on spring onto the other pin.
5. Remove the spring trolley nut from the threaded shaft.
6. Insert the trolley threaded shaft through the hole in the trolley.
HARDWARE
Master
Link
Threaded Shaft with Spring Trolley Nut
Sprocket
Figure 3
Threaded Shaft
Master Link
Figure 2
Trolley Connector
Figure 1
Retaining
Slot

9
Assembly
STEP 5 Tighten the belt
1. By hand, thread the spring trolley nut on the threaded shaft until it is finger tight against the
trolley. Do not use any tools.Remove the screwdriver.
2. Insert a flathead screwdriver tip into one ofthe nutring slots and brace itfirmly against the trolley.
3. Tighten the spring trolley nut with an adjustable wrench or a 7/16" open end wrench about a
quarter turn until the spring releases and snaps the nut ring againstthe trolley. This sets the
spring to optimum belt tension.
Nut Ring
BEFORE
1"
(2.5 cm)
Nut Ring
AFTER
1-1/4"
(3.18 cm)
Spring
Trolley Nut
Nut Ring Slot
STEP 6 Install the sprocket cover
To avoid possible SERIOUS INJURY to finger from moving garage door opener:
lALWAYS keep hand clear of sprocket while operating opener.
lSecurely attach sprocket cover BEFORE operating.
1. Position the sprocket cover over the sprocket asshown and fasten to the mounting plate with
8x3/8" hex screws provided.
You have now finished assembling your garage door opener. Please read the following warnings
before proceeding to the installation section.
Hex Screw #8x3/8"
(Packed with the
sprocket cover)
HARDWARE
Hex Screw #8x3/8"
Sprocket Cover