30 June 2026
How to Install a Merlin Gate Keypad
A step-by-step guide to mounting, wiring, and programming a Merlin E850M keypad for your sliding or swing gate motor.
A gate keypad gives you code-based access without needing a remote control. It's ideal for pedestrian gates, shared driveways, rental properties, or anywhere you need to give access to multiple people without handing out remotes. The Merlin E850M is a wired, weather-resistant keypad that connects directly to your gate motor's control board.
This guide walks through the full installation process — from choosing a mounting spot to programming your access codes. If you're handy with basic tools and comfortable with low-voltage wiring, you can do this yourself. If not, we install these regularly and can have it done in under an hour.
What you'll need
Choose the right mounting location
Mount the keypad on the entry side of the gate, at a comfortable height (roughly 1.2–1.4m from ground level). Pick a spot that's sheltered from direct rain and sprinkler spray. The keypad needs to be within cable run distance of the motor — the E850M uses a low-voltage wired connection back to the motor's control board. Avoid mounting on a gate leaf that moves — always mount on a fixed post or pillar.
Tip: If you're mounting on a brick or rendered pillar, use a masonry bit and wall plugs. On timber or steel posts, self-tapping screws work fine.
Run the cable from keypad to motor
The E850M keypad connects to the gate motor control board via a 2-core low-voltage cable (typically 14/0.20 or similar). Run the cable from the keypad location back to the motor housing. Use conduit or UV-rated cable if the run is exposed to sunlight. Keep the cable away from 240V mains wiring to avoid interference. Leave enough slack at both ends for termination.
Tip: Underground cable runs should be in conduit at a minimum depth of 300mm. Mark the route so nobody digs through it later.
Wire the keypad to the control board
Open the motor housing and locate the control board. The keypad connects to the 'push button' or 'PB' input terminals — the same input a wired wall button would use. Connect one core to the PB terminal and the other to the COM (common/ground) terminal. The keypad acts as a dry contact switch — when a valid code is entered, it briefly shorts these two terminals to trigger the gate.
Tip: Take a photo of the control board terminal layout before you start. If anything goes wrong, you can refer back to the original wiring.
Program your access code
Power up the motor and the keypad should illuminate. To set your PIN on the E850M: press and hold the 'P' (program) button until the LED flashes, then enter your desired 4-digit code and press '#' to confirm. The LED will flash to confirm the code is stored. You can program multiple codes — useful for giving a different code to a cleaner, gardener, or tenant so you can delete individual codes later without changing everyone's access.
Tip: Avoid obvious codes like 1234, 0000, or your street number. If you need to give temporary access, program a separate code and delete it when it's no longer needed.
Test the keypad operation
Enter your new code and press '#'. The gate should activate — open or close depending on its current state. Test the code several times from both directions. If the gate doesn't respond, double-check the wiring at both ends (keypad terminals and motor control board). Also confirm the motor is in 'auto' mode, not 'manual release' — a motor in manual mode won't respond to any input.
Tip: Test in both daylight and at night. The E850M has a backlit keypad, but confirm the buttons are easy to read and press in low light.
Seal and tidy the installation
Once everything works, seal any cable entry points with silicone to prevent water ingress. Tidy cable runs with cable clips or conduit. If the keypad is surface-mounted, ensure the mounting plate sits flush against the pillar with no gaps where water can pool behind the unit. Replace the motor housing cover and ensure all terminal screws are tight.
Tip: A neat installation lasts longer. Loose cables get snagged, chewed by animals, or damaged by garden tools.
When to call a professional
Keypad installation is straightforward for anyone comfortable with basic wiring. But there are situations where it's worth getting a professional to do it right:
Keypad supply & install
We supply and install the Merlin E850M keypad. Price includes the unit, cable run, mounting, programming, and a full test.
$125
Call-out fee — includes the first 30 minutes onsite. Keypad unit and additional labour quoted on inspection. Prepayment required.
Related pages
Want us to install it for you?
We supply and install Merlin keypads across Brisbane Southside, Logan, and the Northern Gold Coast. Usually done in under an hour.