For: Admins and Managers
Use this guide if your Monitor Pro sensors or Hub have stopped sending readings to your dashboard. Work through each section in order to identify and resolve the issue.
My sensor shows an outage, but the LCD is still displaying a temperature — is this a system bug?
No. The LCD on the sensor shows the last recorded temperature regardless of whether the reading reached the Hub. An outage on the dashboard means the Hub did not receive the transmission — not that the sensor stopped working. This is usually caused by an intermittent signal: the sensor transmits every 15 minutes, and if the Hub misses that window due to obstruction, distance, or interference, the dashboard logs it as an outage even if the sensor itself is functioning. Run through the quick checks below to identify the cause.
In this article
Quick checks before you start
Check the dashboard. Log in to your Safe Food Pro dashboard and select the Sensors tab.
Are all sensors offline, or just one?
Check the Last Reading Time for the affected sensor(s).
Check the Battery Voltage — should be above 3.5V.
Check the Signal Strength (RSSI) — ideally better than -100dBm. Values near -120dBm indicate a very weak signal.
Power cycle the Hub. If all sensors stopped reporting at the same time, the Hub is the likely cause.
Unplug the Hub from the power outlet.
Wait 30 seconds, then plug it back in.
Wait a few minutes for it to reconnect. Readings should reappear on the dashboard within the hour.
Power cycle the sensor. If only one sensor is offline, try restarting it.
Carefully unscrew the sensor casing.
Remove the battery and wait 30 seconds.
Reinsert the battery and screw the casing back on securely.
Place the sensor near the Hub and check the dashboard over the next hour.
Run a sensor communication test. Stand next to the Hub and press the Power button on the sensor once.
If the Hub's RF light flashes blue — the sensor is communicating successfully.
If there is no blue flash — the sensor is not reaching the Hub. Continue troubleshooting below.
Troubleshooting Hub issues
If all sensors stopped reporting at the same time, or if you have never received readings, the Hub is the most likely cause.
Check the Hub lights
Check your Hub's indicator lights and compare them to the expected healthy state. For a full breakdown of every light pattern, see Hub Indicator Lights Reference.
A healthy Hub shows:
Power light (Red) — solid red continuously
Network light (Green) — flashing when sending data, solid for 2 seconds after a successful send, slow flash when idle
RF light (Blue) — brief flash each time a sensor reading is received
If any light is behaving differently, move to the relevant section below.
Troubleshooting network issues
Network problems are typically indicated by the green Network light on the Hub.
LAN Hub (WH-2)
Check that the Ethernet cable is securely plugged into the LAN port on the Hub and into your router or network switch. Try a different port on the router. Check the cable for damage.
Confirm your router is powered on and has internet access. Try restarting your router.
If your site has a managed network or firewall, Safe Food Pro Hubs require outbound access to
admin.lora.safefoodpro.co.nzvia TCP port 3000. Contact your IT administrator to confirm this port is open and the address is not blocked.
4G Hub (WH-3)
Confirm the SIM card is active and has data credit with the provider.
Check that the SIM card is installed correctly in the Hub. Power cycle the Hub after re-seating the SIM.
Confirm the Hub is in a location with adequate mobile reception. Metal enclosures and basement locations can block signal.
Check that the 4G antenna is screwed on firmly.
If network troubleshooting does not resolve the issue, contact [email protected].
Troubleshooting power issues
Power issues are usually indicated by the red Power light or the Hub not turning on at all.
Symptoms
The Hub does not turn on (no lights at all).
The red Power light is flashing rather than solid.
Steps
Check that the power adaptor cable is securely connected to the Hub and the adaptor block is firmly plugged into the wall socket.
Try plugging the adaptor into a different wall outlet.
Check the small blue indicator light on the adaptor block:
Flashing blue — the power adaptor itself is faulty.
Solid blue — the adaptor is providing power; the issue is likely within the Hub unit.
If you suspect a faulty power adaptor or Hub, contact [email protected].
Troubleshooting a single offline sensor
If only one sensor has stopped sending readings, start by selecting the Sensors tab on the dashboard and checking that sensor's Last Reading Time, Battery Voltage (needs to be above 3.5V), and Signal Strength (RSSI) (ideally better than -100dBm).
1. Check or replace the battery
Low battery is the most common cause of a single sensor failing.
Battery type: Sensors use a 3.6V Lithium battery (EVE ER18505 or similar). Standard AA alkaline batteries will not work.
Battery life: Typically around 3 years, but extreme cold significantly shortens this.
To replace the battery:
Carefully unscrew the sensor casing.
Note the orientation (+/-) of the existing battery.
Remove the old battery.
Insert the new 3.6V Lithium battery in the correct orientation.
Screw the casing back together securely, ensuring any seals are seated correctly.
After replacement, the sensor should appear on the dashboard within 15 minutes. Replacement batteries are available from the Safe Food Pro NZ Shop or Safe Food Pro AU Shop.
2. Check signal strength and placement
If the battery is good but the sensor is still offline, it may be too far from the Hub or the signal is being blocked.
RSSI signal strength guide:
Good: better than -100dBm (e.g. -60, -75, -90dBm)
Weak: -100dBm to -120dBm — prone to dropouts
Very poor: worse than -120dBm or no reading
Common signal obstructions:
Metal — fridge/freezer walls, stainless steel shelving, large containers
Concrete — thick walls or floors
Water or ice — dense liquid storage, significant ice build-up
Fully packed cool rooms or freezers
Microwaves, large electric motors, or other high-power radio equipment nearby
To resolve a range or obstruction issue:
Temporarily move the sensor next to the Hub. Wait up to an hour and check if it appears on the dashboard with a strong signal.
If yes — the original location has a range or obstruction problem. Continue with the steps below.
If no (and battery is good) — the sensor may be faulty. Contact support.
If the sensor can be repositioned, move it inside the fridge or freezer closer to the door, higher up, or away from metal walls and corners. Ensure the antenna is attached and oriented vertically.
If the sensor cannot be repositioned, move the Hub closer to the sensor instead. Keep the Hub in the open and away from metal cabinets. For LAN Hubs, a longer Ethernet cable may be required.
3. Check for physical damage or environmental issues
Inspect the sensor casing for cracks, signs of moisture ingress, or antenna damage.
Confirm the sensor is within its operating range (-40°C to +125°C). Battery performance degrades significantly below freezing or above 50°C.
If the sensor was recently moved between very different temperatures, allow time for any condensation to clear before assuming a fault.
4. Check sensor assignment
Log in to the Admin Console.
Navigate to Equipment and confirm the sensor ID is still correctly assigned to the intended piece of equipment.
Still having trouble? Contact support
If you have worked through these steps and the issue is not resolved, contact [email protected].
To help diagnose the issue faster, include the following in your message:
Your business name
Which hardware is affected — Hub model (WH-2 or WH-3) or specific Sensor ID/Name
If a Hub issue: the current status of the Power, Network, and RF lights
If a sensor issue: the Sensor ID, Last Reading time, Battery Voltage, and Signal Strength (RSSI) from the dashboard
The sensor's location (for example: walk-in freezer, back wall, near stainless steel shelving)
Approximate time the issue started
The troubleshooting steps you have already tried