Every FM350 device uses two independent communication paths. Understanding which path has a problem is the first step in any troubleshooting scenario.

Quick Decision: Is the issue happening during on-site installation (likely Bluetooth or initial LTE setup), or was the device previously working and has stopped uploading data (likely LTE/cellular)? This determines where to start troubleshooting. 

How You Know There’s a Problem

You may have an LTE cellular issue if any of the following are true:

• On the Device: After pressing and holding the Play button for 3 seconds, the Wireless icon turns solid red and remains for approximately 30 seconds.
• WaterCompass Installer App: Connect via Bluetooth, then tap View Device. Cellular Connection shows “Fail” and no recent upload (Last Upload date is stale) or Signal Strength shows “Weak.”

Step 1: Check the Antenna Connection

• Verify the antenna cable is securely connected to the SMA connector on the device (hand-tight). Inspect the antenna and cable for any visible damage or kinks.
• After checking, press and hold the Play button for 3 seconds. Wait 1–2 minutes and watch for the LED to progress from yellow → green → solid green. If the Wireless icon turns solid green, the connection was successful.

Step 2: Perform a Visual Inspection of the Antenna and Cable

Conduct a thorough inspection of the antenna, antenna cable, connectors, and any extensions at the installation site:

• Is the antenna physically damaged? If yes, replace the antenna.
• Is the antenna cable physically damaged? If yes, replace the antenna.
• Is the antenna extension physically damaged (if applicable)? If yes, replace the extension only.
• Is the SMA connector corroded? If yes, the device must be replaced.

After addressing any physical issues, press and hold the Play button for 3 seconds and watch for solid green.

Step 3: Optimize Antenna Placement

• Confirm the antenna is mounted as high as possible within the installation environment. Remove any obstructions between the antenna and open air. If the device is installed in a meter vault, position the antenna as close to the vault opening or lid as possible using the antenna placement template.
• After repositioning, press and hold the Play button for 3 seconds. If the Wireless icon still turns solid red, continue to Step 4.

Step 4: Relocate or Extend the Antenna

• Try mounting the antenna in a different location within the installation environment. If a Wilson Cellular Network Test Kit is available, perform spot tests around the meter location to identify the strongest signal area before committing to a new mount point.
• If relocation improves the signal but the device cannot be moved to match, install an antenna extension cable to bridge the distance. For meter vault installations, this may involve excavating near the vault, drilling through the vault wall, and extending the cable to an antenna installed in an adjacent valve box above ground.
• After relocating or extending, press and hold the Play button for 3 seconds. Confirm the Wireless icon turns solid green. Then verify on the UltraSonix Dashboard that the device shows Online with an updated Last Upload timestamp.

Step 5: Run App Diagnostics to Confirm End-to-End Connectivity

• Connect to the device via Bluetooth, then navigate to View Device → three-dot menu (⋮) → Device Diagnostics. The expected result is Cellular Event = Ready and State Machines = (9,6,7) or (9,6,5). Capture a screenshot of the diagnostics results for the support record.
• After diagnostics complete, check the UltraSonix Dashboard. Connection Status should show the current upload time and signal strength at Medium or greater.

How You Know There's a Problem

You may have a Bluetooth issue if any of the following are true:

• The WaterCompass Installer App does not find the device serial number in the Bluetooth device list.
• The app shows “Not Connected” or fails to pair after selecting the device.
• The Wireless icon on the FM350 is not blinking blue, which would indicate Bluetooth advertising mode. 

Step 1: Confirm the Device is in Bluetooth Advertising Mode

• Press the Bluetooth button on the device once. The Wireless icon should begin blinking blue. If the icon does not respond, the device may be in Shipping Mode, mid-firmware update, or unresponsive. Refer to the Firmware Update in Progress or Stuck.
• After pressing the bluetooth button, open the WaterCompass Installer App and tap Connect. The device serial number should now appear now the list. 

Step 2: Check Proximity and Interference

• Ensure the phone or table is within 15 feet of the device. Confirm Bluetooth is enabled on the phone or tablet. If the device list does not refresh, close and reopen the WaterCompass Installer App.
• After checking, tap Connect in the app and select the device serial number. The app should show “Connected” and allow you to proceed.

Step 3: Cycle the Device Out of Cellular Mode

• If the device was recently in an LTE call (Play button was pressed), it may still be in cellular mode. Wait for the cellular cycle to complete (approximately 2 minutes), then press the Bluetooth button again. 
• The app should now see the device and connect successfully.

How you Know There's a Problem

A firmware update on the FM350 is indicated by the following LED combination:

• Wireless (Communication) icon: Solid Red
• Water Droplet icon: Solid Green

A firmware update may appear stuck if the LEDs remain in the pattern for more than 15 minutes, or if the device does not respond to button presses after the expected update window. 

Step 1: Wait - Do not Press Any Buttons

• Firmware update can take up to 15 minutes to complete. Pressing buttons during an update will interrupt the process and can  cause device issues. Allow the full 15 minutes before taking further action. 
• After 15 minutes, press and hold the Play button for 3 seconds to check if the device responds normally. 

Step 2: Verify the Update Completed

• Press and hold the play button on the device to initiate LTE cellular communication.
• Connect to the device via Bluetooth and navigate to the View Device to check the communication status. 

How you Know There's a Problem 

You may have a no-flow issue if any of the following are true:

• WaterCompass.net: The various usage graphs show zero flow since the installation date.
• WaterCompass Installer App: View Pulses shows no pulse count increasing while water is running.
• FM350 LED Indicator: The Water Droplet LED is solid red (no water detected in pipe), or PSR/Gain shows "Fail" on the UltraSonix Dashboard.

Step 1: Check Pipe Setup Results in the Installer App

Connect to the device with the Installer app via Bluetooth. Review the following indicators in the app and on the device:

• PSR: Should display 0 (pass). A value of -1 means pipe setup needs to be re-run.
• Gain: Should display pass, typically 58 dB or lower. If red or fail, the device may not have adequate acoustic contact with the pipe.
• Water Droplet LED: Should be solid green after pressing Play. If solid red, the device is not detecting water in the pipe.
• If PSR and Gain both pass but flow is still not detected, skip to Step 3.

Step 2: Verify Physical Installation

Inspect the device and pipe for the following:

• Confirm the device is securely fastened to the pipe with a zip tie tensioner.
• Verify the flow direction arrow printed on the device matches the actual flow direction of the pipe.
  • Note: The Play button points in the same direction as the flow direction arrow located on the bottom of the device. 
• Horizontal pipes: The device must be mounted on the side of the pipe, not on top.
• Vertical pipes: Water flow must be traveling upward. Ultrasonic sensors cannot read downward flow.
• If the pipe surface was not properly prepared during installation, remove the device, clean the pipe surface thoroughly with emery cloth, apply dielectric grease to both the pipe and transducers, and reinstall the device.

Step 3: Re-Run Pipe Setup

• Connect to the device via Bluetooth, then navigate to the three-dot menu and select Run Pipe Setup, followed by Run Setup, then OK.
• After pipe setup completes, verify that PSR and Gain both show pass. 
• Then run water and open View Pulses in the WaterCompass Installer App to confirm real-time flow detection. On the UltraSonix Dashboard, the Water Droplet LED should turn green and the Flow History graph should begin populating.

You may not have a flow interruption issue if the following are true:

• Device Communication: The device has stopped communicating. 
• Irrigation meters: High usage for one day followed by several days of no usage is normal cycle behavior.
• Seasonal shutdowns: Irrigation systems may be shut off for winter months.
• Vacant buildings: Domestic meters may show zero flow if the building is unoccupied

If the zero-flow period aligns with any of the above, no action is needed. Continue monitoring and verify that flow resumes when expected.

How You Know There's a Problem

Step 1: Check Device Attachment to Pipe

The device may have loosened from the pipe over time due to vibration, temperature changes, or zip tie fatigue. Inspect the installation and check the following:

• Examine the zip ties and tighten or replace them if loose. Use a zip tie tensioner to ensure a secure fit.
• If the device has shifted position on the pipe, remove it, clean the pipe surface thoroughly with emery cloth, apply fresh dielectric grease to both the pipe and transducers, and re-secure the device.

Step 2: Verify Pipe Setup Is Still Valid

• Check PSR and Gain. If either indicator shows fail, re-run Pipe Setup from the WaterCompass Installer App by connecting via Bluetooth, navigating to the three-dot menu, and selecting Run Pipe Setup.
• After tightening and/or re-running pipe setup, run water and open View Pulses in the WaterCompass Installer App to confirm real-time flow detection. Verify that PSR and Gain both show pass. Monitor the Flow History graph over the next 24 hours to confirm that data resumes consistently.

Step 3: Run Diagnostics via the WaterCompass Installer App

• Connect to the device via Bluetooth, then navigate to View Device → three-dot menu (…)→ Device Diagnostics. Confirm cellular event = Ready and State Machine = (9,6,7) or (9,6,5). 
• Monitor the WaterCompass dashboard over the next 24 hours to confirm the device resumes its daily upload cadence. 

The FM350 has two icons on the face of the device: a Wireless icon that indicates communication status and a WaterDroplet icon that indicates pipe detection status. 

Wireless Icon (Communication Status)

Water Droplet Icon (Pipe Detection Status)

The following thresholds are used to evaluate device health. Values outside the healthy range may indicate a hardware issue, installation problem, configuration problem, or need for remounting.

This section covers state machine codes for UltraSonix flow monitors. Use this as a reference when interpreting device status or troubleshooting issues identified in the UltraSonix Dashboard or WaterCompass Installer App.

Via Button Presses

Use this procedure if you need to return the device to Shipping Mode and cannot use the WaterCompass Installer App. 

1. Have a timer ready.
2. Press and hold the Play (triangle) button and start the timer.
3. At 20 seconds, continue holding Play and also press and hold the Bluetooth button.
4. Both LEDs should go solid blue. Continue holding both buttons.
5. When the LEDs go out, release both buttons.
6. The LEDs may briefly go solid blue again and then turn off on their own.

To verify the device is in Shipping Mode, quick-tap the Play button. If the LEDS turn solid blue for 2 seconds and then go out, the device is in shipping mode. If the LEDs blink for 5 seconds and then go out, the device is in shipping mode. 

Via the WaterCompass Installer App

1. Connect to the device via Bluetooth, then tap View Device.
2. Tap the three-dot menu (…) in the top right corner.
3. Select Reset to Shipping Mode, then confirm the Reset.
4. Bluetooth will disconnect and display “Not Connected”.