Overview
In some cases, a Shelly Wave relay device may show ON in the gateway, but the connected load does not switch.
The most common symptoms are:
The gateway - controller shows the output as ON
There is no relay click
There is no voltage on the output terminal
The connected load does not turn on
Power, current, or voltage values do not change as expected
If the device receives Z-Wave commands but the relay does not click and the output has no voltage, the issue may be related to the output stage, relay, wiring, protection state, or configuration.
This guide explains how to check the device step by step.
Safety first
Before opening the wall box or touching the wiring, turn off the breaker.
Live voltage checks must only be done by a qualified person. If you are not fully comfortable measuring mains voltage, contact an electrician.
Shelly Wave relay devices may switch mains voltage. Incorrect handling can cause electric shock, device damage, or fire risk.
Output terminal naming
Different Shelly Wave devices may have one, two, or three outputs.
Depending on the device model, the output terminals may be marked as:
| Device type | Output terminals |
|---|---|
| Single-output device | O or O1 |
| Two-output device | O1 and O2 |
| Three-output device | O1, O2, and O3 |
The same troubleshooting logic applies to each output.
For example:
For output 1, check O1
For output 2, check O2
For output 3, check O3
When checking voltage, always measure the selected output against N, if this is valid for the wiring type.
1. Confirm that it is not only a gateway state issue
First, check if the gateway is only showing a wrong state. In your Z-Wave gateway, switch the output ON and OFF several times.
Watch the following:
The gateway entity state
Logs or events
Power, voltage, and current readings reported by device if available
The physical relay click
The connected load
If the gateway state changes to ON, but there is no relay click and no output voltage, the device logic may receive the command but the relay or output stage may not activate.
If the device can be controlled by more than one source, test all sources.
Examples:
Gateway (Hub)
Z-Wave direct association
Automation
Local wall switch
If all control methods fail, the issue is less likely to be caused by an automation or gateway configuration.
2. Test local control
Do not test only through Z-Wave. Also test local control from the physical switch input, if accessible or available. For single-output devices, test the switch connected to SW or SW1.
For multi-output devices, test the related switch input:
| Input | Related output |
|---|---|
| SW1 | O1 |
| SW2 | O2 |
| SW3 | O3 |
Recommended test:
Turn off the breaker.
Open the wall box safely.
Check that the switch input is connected correctly.
Restore power only when it is safe.
Press the wall switch.
Listen for the relay click.
Measure if the related output becomes live.
How to understand the result
| Test result | Possible meaning |
|---|---|
| No click from Z-Wave and no click from local control | Possible hardware fault, protection state, or device issue |
| Click from local control but not from Z-Wave | Possible gateway, association, or configuration issue |
| Click occurs but no output voltage | Possible relay contact, terminal, wiring, or supply issue |
| Only one output fails on a multi-output device | Possible issue with that specific output channel or wiring |
| All outputs fail | Possible supply, protection, configuration, or device-level issue |
3. Check LED and alarm state
Check the LED on the device and check the gateway for alarms.
Shelly Wave devices may report protection events such as:
Overcurrent
Overheat
Overvoltage
Overload
Protection triggered
If a protection state is active, the device may switch off the output and prevent normal operation. Check for red LED alarm blinking and check the notifications in the gateway or Z-Wave JS UI.
If a protection alarm is active:
Turn off the breaker.
Disconnect the load from the affected output.
Secure the wires safely.
Power the device again.
Test the output without load or with a known small resistive load.
Do not continue using the device with a load that triggers protection.
4. Power-cycle the device
A power cycle can clear a temporary state.
Steps:
Turn off the breaker.
Wait at least 30 seconds.
Turn the breaker back on.
Or use the Parameter 117 to reboot the device.
Test the output again.
After the power cycle, test control from:
Your gateway
Direct association, if used
Local switch input
If the relay starts working again after a power cycle, the issue may have been a temporary firmware or protection state. If it fails again when the load is connected, check the load and wiring.
5. Verify configuration parameters
Incorrect parameters can make the output behave in an unexpected way.
Check the parameters in your gateway - controller.
Important parameters for single-output devices
| Parameter | Function | What to check |
|---|---|---|
| Parameter 23 | O/O1 contact type, NO/NC | Check if output logic is inverted |
| Parameter 19 | O1 Auto OFF timer | Check if output turns off immediately |
| Parameter 20 | O1 Auto ON timer | Check if output turns on unexpectedly |
| Parameter 1 | SW/SW1 switch type | Check if local switch behavior is correct |
Important parameters for two-output devices
| Parameter | Function | What to check |
|---|---|---|
| Parameter 23 | O1 contact type, NO/NC | Check O1 relay logic |
| Parameter 24 | O2 contact type, NO/NC | Check O2 relay logic |
| Parameter 19 | O1 Auto OFF timer | Check O1 timer |
| Parameter 20 | O1 Auto ON timer | Check O1 timer |
| Parameter 21 | O2 Auto OFF timer | Check O2 timer |
| Parameter 22 | O2 Auto ON timer | Check O2 timer |
| Parameter 1 | SW1 switch type | Check SW1 behavior |
| Parameter 2 | SW2 switch type | Check SW2 behavior |
Important parameters for three-output devices
| Parameter | Function | What to check |
|---|---|---|
| Parameter 23 | O1 contact type, NO/NC | Check O1 relay logic |
| Parameter 24 | O2 contact type, NO/NC | Check O2 relay logic |
| Parameter 106 | O3 contact type, NO/NC | Check O3 relay logic |
| Parameter 19 | O1 Auto OFF timer | Check O1 timer |
| Parameter 20 | O1 Auto ON timer | Check O1 timer |
| Parameter 21 | O2 Auto OFF timer | Check O2 timer |
| Parameter 22 | O2 Auto ON timer | Check O2 timer |
| Parameter 29 | O3 Auto OFF timer | Check O3 timer |
| Parameter 30 | O3 Auto ON timer | Check O3 timer |
| Parameter 1 | SW1 switch type | Check SW1 behavior |
| Parameter 2 | SW2 switch type | Check SW2 behavior |
| Parameter 3 | SW3 switch type | Check SW3 behavior |
Contact type explanation
The output contact type defines if the relay works as normally open or normally closed.
For a standard normally open setup:
Output OFF = no voltage on output
Output ON = voltage on output
If the contact type was changed to normally closed, the logic may look inverted.
For the symptom where the gateway shows ON but the relay does not click, the contact type is important to check, but it is not the only possible cause.
6. Measure supply and output voltage
This step must only be done by a qualified person.
With proper mains safety:
Confirm supply voltage between L and N at the device.
Command the output OFF.
Measure voltage between the selected output and N.
Command the output ON.
Measure voltage between the selected output and N again.
For a standard EU AC installation with normally open contact type, the expected result is:
| State | Expected voltage |
|---|---|
| Output OFF | Approximately 0 V between O/O1/O2/O3 and N |
| Output ON | Approximately 230 V between O/O1/O2/O3 and N |
For multi-output devices, repeat the test for each affected output:
O1 to N
O2 to N
O3 to N, if available
If L-N supply is present, the gateway shows ON, but the output stays at 0 V and there is no relay click, the relay or output driver may be faulty.
Also check the terminals with power off.
A loose wire on L, N, or the output terminal can cause a dead output.
7. Disconnect the load and retest
A faulty or unsuitable load can trigger protection or damage relay contacts.
With power off:
Disconnect the load from the affected output.
Cap and secure all wires safely.
Power the device again.
Command the output ON and OFF.
Listen for the relay click.
Result explanation
| Result | Possible meaning |
|---|---|
| Relay clicks without load but not with load | Load may be faulty, shorted, or causing overcurrent/inrush |
| Relay still does not click without load | Possible device hardware failure or internal protection |
| Relay clicks but output voltage is still missing | Possible relay contact or terminal issue |
Loads that can create high inrush or electrical stress include:
Pumps
Valve actuators
Transformers
LED drivers
Fans
Refrigerators
Air conditioners
Other inductive or capacitive loads
For some inductive or capacitive loads, an RC snubber may be required.
8. Compare with a known working device
If you have another working Shelly Wave device of the same model, compare:
Firmware version
Z-Wave parameters
Device class
Entity behavior
LED behavior
Relay click
Output voltage
Power and current readings
For multi-output devices, compare each channel.
Example:
O1 on the affected device compared with O1 on the working device
O2 on the affected device compared with O2 on the working device
O3 on the affected device compared with O3 on the working device, if available
Do not swap modules or loads unless this can be done safely by a qualified person. If a known working module works on the same circuit and load, and the affected one does not, this points to a device fault.
9. Re-interview or re-include only after hardware checks
A Z-Wave re-interview or re-inclusion can help if the gateway missed device information. However, if the device receives commands and reports the ON state, but the relay does not click, re-inclusion should not be the first step.
Before factory reset, try:
Re-interview node (reconfigure)
Refresh values
Rebuild routes, if communication is unstable
Firmware update, if available
Remote reboot, if supported by the device or gateway
Z-Wave JS UI re-interview
Open Z-Wave JS UI.
Select the affected device.
Open Advanced.
Run Re-interview Node.
Wait until the process is complete.
Test the output again.
Fibaro HC
- On the Home - main dashboard on the affected device click on the gear icon
- Select the Device configuration tab
- Press the Reconfigure Device button
Wait until the process is complete.
Test the output again.
Factory reset
Use factory reset only as a later step.
Factory reset can remove:
Associations
Routing information
Gateway connection
Node ID
Energy counter values, if supported
After factory reset, the device must be included again.
10. Likely conclusion
The device is likely physically faulty if all of the following are true:
Z-Wave commands are received
Gateway or Hub state changes to ON
Local control also does not make the relay click
Supply voltage between L and N is present
Output stays without voltage
No active protection alarm explains the issue
Power cycle does not restore operation
The same load works with another known working device
In this case, the possible fault may be in:
Relay coil
Relay driver
Internal relay contact
Output switching path
Output measurement circuit
Stop using the device on that load and contact Shelly support or your seller for warranty handling.
The most important symptom is the missing relay click when the output is commanded ON.
Information to send to support
When contacting support, include:
Device model
Firmware version
Gateway model
Z-Wave controller type
Z-Wave JS UI version, if used
Wiring diagram or photo, if safe to provide
Load type and power
Which output is affected: O/O1, O2, or O3
Whether the relay clicks
Measured voltage between L and N
Measured voltage between output and N when ON
Alarm or notification messages
Parameter values for contact type and Auto OFF/Auto ON timers
Result of power cycle
Result of test without load
Result of re-interview, if performed
Summary
If a Shelly Wave relay device shows ON in the gateway but there is no relay click and no voltage on the output, first check safety, wiring, local control, alarms, parameters, and the load.
For devices with multiple outputs, test each output separately.
If the device receives commands but the affected output never clicks or provides voltage, and no wiring, load, or parameter issue is found, the device may have a hardware fault.