Every FM250 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 FM250 is indicated by the following LED combination:

• Play button LED: Solid Green
• Bluetooth button LED: Solid Red

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 do you know there’s a problem?

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

• WaterCompass.net: The Interactive Analytics page shows zero flow since the installation date.
• UltraSonix Dashboard: The Flow History graph shows zero flow since the installation date.
• WaterCompass Installer App: View Pulses shows no pulse count increasing while water is running.

FM250 — Sensor-Based

Step 1: Verify Sensor Attachment and Position

• Confirm the sensor is securely attached to the meter register with the hose clamp. Check the position: the sensor should be at the 3 o’clock or 9 o’clock position on the register. If an AMI/AMR device is present, use the opposite side. Confirm the bottom of the sensor rests just above the bottom of the meter register.
• For flush-mount registers where the register is flush with the meter body, the sensor must be glued at the 6 o’clock position.
• After verifying, run water for at least 1 minute. In the WaterCompass Installer App, connect via Bluetooth and open View Pulses. The pulse count should increase steadily with flow.

Step 2: Reposition the Sensor

• If no pulses are detected at the current position, move the sensor to the alternate clock position (e.g., from 3 o’clock to 9 o’clock). Re-tighten the hose clamp securely.
• After repositioning, run water again for 1 or more minutes and check View Pulses. If pulses now appear, proceed with calibration.

FM250 — Pulse-Based

Step 1: Verify Wiring

• Check the wire configuration from the meter register to the device. Refer to the Knowledge Base article for the correct pulse output wire configuration for the specific meter type.
• After verifying the wiring, run water for 1 or more minutes and check View Pulses in the WaterCompass Installer App. The pulse count should increase with flow.

How do you know there’s a problem?

You may have a flow interruption issue if the following are true:

• UltraSonix Dashboard: The Flow History graph shows data for a period, then drops to zero.
• Device Communication: The device is still communicating (Last Upload is current), but flow readings are flat.

Step 1: Check Sensor or Wire Attachment

• Sensor-based FM250: The sensor may have been physically displaced from the meter register over time. Verify the sensor is still secure and in the correct position (3 o’clock or 9 o’clock). Re-tighten the hose clamp if loose.
• Pulse-based FM250: The wire connection may have loosened at the meter or at the device. Inspect both ends and re-secure if needed.

After securing the sensor or wire, run water for 1 or more minutes and check View Pulses in the WaterCompass Installer App. The pulse count should increase with flow.

When pressed but not held down, both buttons will wake the device. The device will either enter the shipping state or the state the device was in prior to powering it down. 

LED Color	LED Behavior	Example
Solid Yellow (both LEDs)	Displays when the device is in Shipping mode.
Blink Yellow (both LEDs)	Displays when the device is advertising itself for Bluetooth connectivity in debug mode.
Blink Yellow (bluetooth LED Only)	Displays when the device is connecting to LTE cellular.
Blink Green	Displays when the device has successfully connected to LTE and is waiting for the cloud servers to respond.
Solid Green	Displays when the device has successfully connected to the cloud via LTE.  The LED will remain on for ~10 minutes after successfully connecting.
Blink Red	Displays when the device failed to connect to LTE The LED will remain on for ~5 minutes after trying.
Solid Red	Displays when the unit failed to connect to the cloud via LTE. The LED will remain on for ~ 1 minute.
Off	Displays when the device is In shipping mode or Bluetooth is connected in Debug mode or 10 minutes have passed since a manually triggered cloud connecting in Meter/Setup mode.

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”.