What the 87802 is
The LiftMaster 87802 is a chain drive opener with a 12V DC motor. LiftMaster does not publish a horsepower number for it. The DC motor starts and stops softly. That helps on heavy sectional doors and tall openings where a basic AC motor would shudder.
Being a chain drive, it handles weight well and lasts a long time when the chain is kept oiled. It is also louder than a belt drive. If there is a bedroom over the garage, you will hear it run.
Light comes from an LED ring around the motor head. It spreads light across the floor better than a single bulb, and you are not up a ladder changing bulbs. Battery backup is built in, so the door still runs when the power goes out in a windstorm. There is no camera in the unit. If you want video you add a separate camera.
It suits an existing chain rail setup where the owner wants the smooth DC motor, the backup battery and the LED light without moving to a belt rail. It also suits heavy wood or insulated steel doors where the extra torque keeps the door from bogging down halfway.
LiftMaster still lists the 87802. We install new ones and repair the ones already out there.
LiftMaster 87802 install and repair, the install part
Mounting the motor head and rail
We start with the header and the ceiling framing. The 87802 head is heavier than a basic opener. If the joists run parallel to the door we add blocking. If they run across it we lag the bracket into two joists. Drywall anchors do not hold. A chain drive shakes them loose.
We put the rail together on the floor and set the chain tension before we lift it. Too loose and the chain slaps the rail every cycle. Too tight and the sprocket bearings wear early. We aim for about half an inch of sag at the middle with the door closed.
The head gets hung, levelled both ways and tied to the header bracket over the door. That bracket needs solid wood behind it. On older houses we sometimes find a rotted header board behind the trim. We fix that before anything gets hung on it.
Travel limits and force
The limits are set with the adjustment button on the opener itself, not the wall control or the app. The up limit stops the door just short of the internal stop. The down limit lets the door touch the floor and then backs off a little so the top panel is not pushed on.
Then the opener runs the door up and down once and learns the force on its own. After that we test it. We lay a 2x4 flat under the door and the door has to reverse when it touches it. We also walk through the photo eye beam while the door is closing and it has to reverse. If the door crushes the 2x4, or reverses by itself on a cold morning when the track is stiff, we fix the door and run the travel setup again.
Safety sensors
Photo eyes go no higher than six inches off the floor. We line them up and staple the wire every foot or so, so a broom or a box does not pull it loose. The sending eye shows a steady amber light and the receiving eye a steady green one. Sensors out of line are the most common reason anyone calls back about any opener.
myQ and Wi Fi
The 87802 works with myQ. We pair it to your Wi Fi on the spot using the app, then test it from the driveway. We turn on alerts so you get a message if the door is left open. If the signal is weak in the garage, a mesh node near the door usually fixes it. Metal doors and foil backed insulation block the signal.
Final checks
We run the door at least ten times. We listen for chain slap and watch the trolley. We pull the power to make sure the backup battery takes over. Then we walk you through the wall control and the manual release.
LiftMaster 87802 repair, what usually goes
Chain stretch and slap
The chain stretches with use. It starts to bow and slaps the rail on every open with a sharp crack. Most of the time we take it up at the trolley adjuster. When it has stretched past the adjustment, we put on a new chain.
Sprocket wear
The sprockets are hard steel but grit and salt air wear the teeth, more so near the water in Ladner and Tsawwassen. A worn sprocket skips under load. The door jerks and the chain jumps. The fix is pulling the motor head and pressing on a new sprocket.
Trolley wear
The trolley rides the rail on nylon wheels and takes a jolt every time the motor starts and stops. Over the years the wheels go flat and the trolley chatters. We replace the trolley and check the rail for gouges. A gouged rail chews up a new trolley quickly.
LED ring goes dark
The ring runs off a small driver board in the head. If the ring flickers or goes out while the opener still works, it is usually the driver board. If the lens is cracked from a ladder knock, we replace the lens.
Backup battery
The backup is a sealed 12V battery and it lasts a few years. When it is done the opener beeps every thirty seconds and the status light flashes orange. We fit a new battery and test it with the power cut.
Logic board
The motor control and the myQ radio sit on the main logic board, and power surges kill it. The opener goes completely dead. No lights, no remotes, no wall control. We check the power coming in with a meter before we replace a board. If the house has no surge protection we will suggest it.
Quick symptom guide
- Opens a foot then reverses. Check the photo eyes, clean the lenses and look for a damaged wire.
- Will not close and the wall control blinks. The sensor circuit is open. Same checks.
- Loud slap from the rail. Take up the chain at the trolley. Replace the chain if it is out of adjustment.
- Motor runs but the trolley does not move. Broken trolley or stripped sprocket.
- Remote works now and then. Try a fresh remote battery and a second remote.
- Light ring flickers or is dark. Driver board or cracked lens.
- Beeps every thirty seconds with an orange light. The backup battery is done.
- Closes then opens again right away. The down limit is set too far. Raise it a little.
- App says offline. Restart the opener and make sure the 2.4 GHz band is on.
Chain rail on older headers
On older garages the header is often lower than today, so the rail can hit the torsion tube or the top roller bracket. We shim the head or trim the rail end to keep the chain clear without touching the spring tension. If the door has a high lift track, the standard rail is too short and the trolley hits the stop early. We fit the extension kit and reset the limits on the same visit.
87802 compared with the belt version
The belt drive model in the same line shares the motor and the battery backup. The difference is the belt, which makes it much quieter with almost no shake into the ceiling. If the garage is under a bedroom, the belt model is worth it. The rails are different, so you cannot switch a chain rail to belt without changing the whole rail.
LiftMaster 87802 FAQ
Does the 87802 work with 5 GHz Wi Fi?
No. It only joins 2.4 GHz networks. If your router uses one name for both bands, we pair it with 5 GHz turned off for a minute or set up a 2.4 GHz guest network. Your phone can stay on 5 GHz.
Should I repair or replace my 87802?
If it is the chain, trolley, sensors, battery or logic board, a repair usually makes sense. If the motor housing is cracked, the rail is bent or several things have failed at once, a new opener is the smarter spend. We show you both and you choose.
Who covers the warranty?
LiftMaster covers the opener parts under its own terms. Our labour is separate and we will explain it when we quote.
What does a visit cost?
The on site assessment is free. A surcharge may apply depending on the area, and we quote it before we come out.
Call us
For LiftMaster 87802 install and repair work call (778) 873-7282. We do LiftMaster 87802 install and repair across Richmond, Delta and Vancouver. We answer 24/7 and we work out of Richmond.