Relay Controllers

Troubleshooting

Diagnosing and resolving common issues with HPzenAi relay controllers.

Relay Controller Not Appearing in the App

Cause: The controller is not connected to the gateway via RS485, the RS485 A/B polarity is reversed, or the controller has a duplicate address on the bus.

How to Fix

• Verify the relay controller has 12V DC power — the power LED should be illuminated.
• Check that RS485 A and B wires are not swapped — reversed polarity prevents detection and is the most common wiring error.
• Confirm the controller's RS485 address is unique on the bus — if two devices share the same address, neither will be reliably detected.
• In the app, go to Gateway → your gateway → RS485 Scan to manually trigger a new device search.
• Use a short test cable (under 1 m) directly between the gateway and controller to isolate whether the issue is the cable run or the device.
• For Wi-Fi stand-alone mode, confirm the controller is in setup mode (blue flashing LED) and follow the Wi-Fi Setup guide.

Channel Not Switching — Load Does Not Respond

Cause: The relay channel is not receiving the switch command, the output terminal wiring is incorrect, or the relay itself has failed.

How to Fix

• Confirm the controller has 12V DC power at its input terminals — no power means no channels can switch.
• In the app, tap the channel and use Manual Control to attempt a direct switch — observe whether the channel LED on the controller illuminates.
• If the channel LED illuminates but the load does not respond, the fault is in the wiring or the load itself — not the controller.
• Verify the load cable is connected to COM and NO, not COM and NC — loads wired to NC will behave in reverse.
• Measure voltage at the COM and NO terminals with a multimeter when the channel is energised — you should read 12V DC.
• If the channel LED does not illuminate when switching from the app, the relay may have failed — contact HPzenAi support for channel-level diagnosis.

Schedule Not Running at the Correct Time

Cause: The controller's internal clock is incorrect due to a wrong time zone setting, or the schedule was not saved correctly to the controller.

How to Fix

• Open the relay controller in the app, tap Schedules, and confirm the schedule is listed with the correct start time, duration, and days.
• Verify the controller time zone is set correctly: Device Settings → Time → Time Zone.
• Check the schedule is enabled — a greyed-out or toggled-off schedule will not execute.
• Confirm the correct channel is assigned to the schedule.
• Delete and recreate the schedule if the stored data appears inconsistent — tap Save after recreating.
• If sunrise/sunset-based schedules are drifting, confirm the gateway's location is correctly set: Gateway → Settings → Location.

RS485 Bus Not Detecting Controller After Adding to Existing Bus

Cause: Address conflict with an existing device, missing termination resistor, or daisy-chain topology broken by a branch connection.

How to Fix

• Power off all devices on the RS485 bus and connect only the new controller to the gateway for the initial address assignment.
• Scan from the app with only the new controller connected — confirm it is detected at its default address (usually 1).
• Assign the new controller a unique address that is not used by any other device on the bus.
• Reconnect all devices and re-scan — all devices should now appear with their unique addresses.
• Verify the bus uses a daisy-chain topology — no star or branch connections — and fit the 120 Ω termination resistor at the last device.
• Check the total bus cable length does not exceed 1,200 m at 9600 baud.

App Showing Wrong Channel State (Shows Open When Closed or Vice Versa)

Cause: The controller status has not synced to the cloud, typically because a manual operation occurred during an internet outage at the gateway.

How to Fix

• Pull down to refresh the relay controller tile in the app — this triggers an immediate status poll from the gateway.
• Check the gateway is online: Main Menu → Gateway — the gateway status should show 'Connected'.
• If the gateway was offline during a channel operation, the app state will be stale until the gateway reconnects and syncs.
• Restart the gateway from the app: Gateway → Settings → Restart, then re-check the channel state.
• If the channel state mismatch is persistent, power-cycle the relay controller and allow 60 seconds for the gateway to re-poll the channel states.

Relay Clicking But Connected Device Not Responding

Cause: The relay is switching correctly but insufficient 12V DC supply voltage or load wiring is preventing the device from operating.

How to Fix

• Measure the 12V DC supply voltage at the relay controller input terminals — it should be 11.5–12.5V under load.
• If voltage sags below 10V when the relay switches, the power adapter is undersized for the connected loads — check the total current draw and use a higher-rated adapter.
• Verify the load's cable connections at the relay output terminals — confirm COM and NO are used, terminals are tight, and the cable is not broken.
• Check the connected device (valve coil, motor starter control circuit) for a fault — test the device independently with a 12V bench supply.
• Inspect the relay output terminals for oxidation or pitting — corroded relay contacts increase resistance and reduce output voltage to the load.

Controller Offline After Power Interruption

Cause: The relay controller or gateway did not automatically reconnect after power was restored.

How to Fix

• Wait 2–3 minutes after power restoration — the controller and gateway reconnect and sync automatically.
• If the controller remains offline after 5 minutes, check the 12V DC supply at the controller input.
• Check the gateway is online — if the gateway itself is offline, the controller will not appear connected even if it is operating normally.
• Any schedules stored on the controller continue to execute locally even during internet or gateway outages — physical valve and device switching is not affected.
• Restart the gateway from the app (Gateway → Settings → Restart) if it remains offline after power is restored.

Wi-Fi Connection Dropping Repeatedly

Cause: Weak Wi-Fi signal at the controller's installation location, or the controller is connected to a 5 GHz network that is not supported.

How to Fix

• Check the Wi-Fi signal strength at the controller location: Device Settings → Network → Signal Strength — it should be better than −75 dBm.
• Confirm the controller is connected to a 2.4 GHz network — 5 GHz networks are not supported.
• Move a Wi-Fi access point or repeater closer to the control panel to improve signal.
• For persistent connectivity issues at the installation site, switch to RS485 via gateway — a wired RS485 connection is more reliable than Wi-Fi for industrial panel installations.
• For XR1, XR2, X1, or X2 models, insert a SIM card and configure cellular APN as a fallback: Device Settings → Network → Mobile Data.

Guided Help Center

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Firmware Update Failing or Stalling

Cause: The internet connection at the gateway dropped during the firmware download, or the controller lost power during the update process.

How to Fix

• Ensure the relay controller is online and the gateway has a stable internet connection before starting the update.
• Do not power off the controller or gateway during a firmware update — the update process takes 3–5 minutes.
• If the update stalls at a percentage, wait 10 minutes before taking action — slow connections can cause apparent stalls.
• If the update fails and the controller is unresponsive, power-cycle the controller — most models automatically roll back to the previous firmware on a failed update.
• Retry the update from Device Settings → Firmware → Update once the controller is back online.
• If the controller remains unresponsive after a failed update, contact HPzenAi support for a manual firmware recovery procedure.