Zooz Switch & Dimmer Troubleshooting

INSTALLATION: Requirements & Best Practices

Below, we'll cover some common inquiries, troubleshooting steps, and switch/dimmer installation best practices that apply to all of our smart switch models.

Maximum Load Ratings

Ensure you verify the maximum acceptable load for your switch model. The majority of our switches cannot be connected to fans, receptacles (outlets), tube lights, or low-voltage transformers.

When calculating your load, remember that LED bulbs have something called inrush current—a brief spike in power draw that occurs when they first turn on. This spike can be 5 to 20 times higher than the rated wattage of the bulb, depending on the driver and capacitor design in each LED. If you have more than 6 bulbs turning on simultaneously, the combined inrush current can exceed the internal relay capacity, even if the continuous load is within limits. LED drivers quickly charge capacitors at startup. When many LED drivers are activated at the same time, their initial draw can be extremely high—even if only for milliseconds. This momentary overload can be enough to damage residential-grade relays, especially when repeated over time.

It’s good practice to derate the max load to protect the switch and extend its life. A good rule of thumb is to use about 70–80% of the rated wattage to account for inrush current and prevent nuisance tripping or premature failure. For a 150W-rated LED switch, a safe continuous load would generally be 105W to 120W of LED load. Please note, this is also dependent on the number of bulbs in your installation. To find the maximum number of bulbs, divide the safe continuous load by the wattage of each bulb. For example, if bulbs are 10W each (typical LED):

105W ÷ 10W = 10 bulbs max (for lower inrush bulbs)
120W ÷ 10W = 12 bulbs max (if drivers are more tolerant)

If your bulbs have a higher inrush characteristics (some bulbs or brands do), consider reducing the count further. We recommend checking your bulb specs for inrush current if available, and always use LED bulbs from reputable manufacturers with known consistent inrush ratings. For multiple bulbs, the inrush current adds up instantaneously—so fewer bulbs are safer.

When Installing the Switch/Dimmer

🔌 Power OFF

Ensure you turn the power off at the breaker and keep it off until the switch is fully installed and all wires are back in the box. Never arrange wires in the box with the power on.

🪛 Isolate Wires and Screws

Strip the wires and insert them into the terminals—never wrap wires around the screws. No bare wire should be exposed on any of the terminals except for ground once the switch is installed.
Isolate the screws with electrical tape to avoid electrical shorts and equipment damage.

🚫 No Power Tools

Always use a standard screwdriver to install the wires in the terminals and the wall plate. Any power tools used to turn the screws can damage the equipment.

📐 Follow the Diagram

Electronic switches need to be connected correctly as per the provided diagram on the first try. Incorrect wiring may damage the switch permanently. Always ensure you have differentiated between the load (connection to the light) and line (power) before installing any Zooz switches—load and line cannot be reversed.

⚪ Neutral

Zooz switches require the proper neutral wire to be connected at all times. Never borrow a neutral from another switch or circuit; you must always use use the dedicated neutral from the same circuit as the power and load wires.

🟢 Ground

A ground connection is necessary in all scenarios and installations for safety and to avoid equipment damage.

🧱 Installation

Keep the switch straight: make sure that the switches in the box are aligned and that no extra pressure is applied to the paddles or metal frame once the wall plate is installed. Don’t overtighten the wall plate on the switches, as this may damage the paddles over time and cause breakage.

Common Reported Issues and The Potential Causes

We've provided a quick chart below for a summary of issues with potential resolutions and shortened explanations. Scroll below for full troubleshooting steps and a detailed explanation.

Issue	Resolution	Explanation
Switch / Dimmer is Unresponsive After Install	Turn breaker off for 10 seconds to reset Check if LED indicator turns on when you press the bottom paddle If LED is on, try a factory reset	A power reset can resolve frozen state. If LED doesn't turn on, there's likely a power issue/wiring issue. A full reset may restore functionality.
ZEN76 Behavior is Reversed (Up = Off)	Verify the connected load is a resistive lighting load only. NO fans, receptacles, or transformers.	Fans are impulse loads and can damage the switch or cause erratic behavior. Use ZEN71, ZEN30, ZEN75, ZEN51, or ZEN52 instead.
Lights Glow When Switch is Off (ZEN76, ZEN77, ZEN73, ZEN74)	Replace one bulb in the fixture with a different/dimmer-friendly LED Use ZEN71 or ZEN72 instead	A small current is always present to support 3-way setups. Some LEDs are sensitive and glow/flicker from this.
LED Indicator is Solid Red After Factory Reset	Turn off power at the breaker to reboot the switch	Factory reset may freeze due to power fluctuation or incomplete reset. A power cycle reboots the internal processor.
Switch Only Works When Dumb Switch is On	Remove Zooz switch immediately Restore mechanical switch Review wiring image guide and send images to support	This behavior means the wiring is incorrect for a multi-way setup. The switch could be damaged if left wired incorrectly.
Light Rapidly Clicks On and Off	Remove Zooz switch immediately Restore mechanical switch Review wiring image guide and send images to support	This is a clear sign of miswiring. Continued use may permanently damage the switch.
Light Turns On Then Immediately Turns Off	Check the load is supported No motion or photocell sensor Only use standard mechanical switches in multi-way setups Recheck all wiring	Unsupported loads (e.g., motion sensors, photocells) or incorrect wiring can cause this loop. Only standard on/off switches are compatible as secondary switches.
Can't Dim Lights with ZEN72 / ZEN74 / ZEN77	Verify bulbs are dimmable Check wiring: load and line wires may be reversed	Reversed wiring often disables dimming functions. Switch may work for on/off but not dimming. Always verify connections per installation guide.

Issue: The Switch/Dimmer is Unresponsive After Installation

Affected Model: ZEN30, ZEN32, ZEN35, ZEN71, ZEN72, ZEN73, ZEN74, ZEN75, ZEN76, ZEN77

Resolution: Try the troubleshooting steps below.

Turn the breaker off for 10 seconds in case the dimmer is in a frozen state. This will reset it.
Check if the LED indicator is ON after you click the bottom paddle. If not, the switch is dead or getting no power – check your power source and ensure you have verified power is connected to the correct terminal.
If the LED is on, try factory reset: press and hold the lower paddle for 10 seconds or more until the LED indicator starts blinking. Release the paddle and immediately after, tap the lower paddle 5 times to complete the reset. The LED indicator will flash blue 3 times and turn red for 3 seconds to confirm a successful reset.

Issue: My ZEN76 has Reversed Behavior (Up is Off, Down is On)

Affected Model: ZEN76 S2 On/Off Switch

Resolution: Check the load.

Explanation: The ZEN76 is rated for lighting loads only (NO FANS, no receptacles, no tube lights/ballasts, no transformers or motors). You can only use the ZEN76 with up to 150 W LED/CFL or up to 600 W incandescent bulbs.

Reversed behavior generally occurs when the ZEN76 is connected to a fan. The ZEN76 is not rated for fan control. A fan is an inductive or impulse load, while lighting loads are resistive. The problem with inductive / impulse loads is that they tend to experience power surges when they are turned on and off, which damages the internal electronic components of the switch itself, either immediately or over time. This kind of surge is not seen with resistive loads, such as light bulbs. While the wattage may be within the device specifications, the load type is not recommended for the majority of our switches.
For on/off control of ceiling or exhaust fans, you could use the ZEN71 Switch as long as the fan is rated under 3A and installed in the last five years. If it's over 3A or an older type which typically draws more than it's rated for we recommend using the relay part of the ZEN30 Double Switch or the ZEN75 Heavy Duty Switch.
If you're looking to keep a toggle-style switch for your fan, then you could install either the ZEN51 Dry Contact Relay for your fan motor, or the ZEN52 Double Relay for your light and fan motor. These devices can be installed behind the switch, or at the light fixture.

Issue: My Lights Glow When the Switch is Off

Affected Model: ZEN73, ZEN74, ZEN76, ZEN77

Resolution: Change one bulb in the fixture, or change switch model.

Explanation: We have found that some lower-quality LED bulbs, as well as certain types of LED rope lights, may behave unexpectedly when used with this switch. This is typically due to the way the switch manages power in order to support 3-way and 4-way wiring configurations, even when it is installed in a simple single-pole setup.

To enable multi-way installations without requiring an add-on switch or traveler wires, the switch is designed to leave a very small amount of current flowing through the circuit even when it is in the off position. This low-level current allows the switch to detect changes in the circuit and maintain accurate status updates. While this design works well with most modern lighting, some LEDs are more sensitive to small amounts of residual current and may flicker, glow faintly, or fail to turn off completely.
If you're seeing this issue, it’s often related to the characteristics of the LED bulbs or fixtures being used. In many cases, replacing just one of the affected bulbs with a higher-quality or different type of LED is enough to resolve the problem. This works by changing the overall load characteristics and reducing sensitivity to the residual current.
If changing bulbs isn’t a viable solution or the issue persists, we recommend using the ZEN71 (for on/off control) or ZEN72 (for dimming), as these switches do not rely on current sensing in the same way and are less likely to cause this type of behavior with sensitive LED fixtures.

Issue: I Factory Reset My Switch/Dimmer and the LED Indicator is Solid Red

Affected Model: ZEN30, ZEN32, ZEN35, ZEN71, ZEN72, ZEN73, ZEN74, ZEN75, ZEN76, ZEN77

Resolution: Power cycle the switch/dimmer at the breaker: this should restore physical function.

Explanation: In rare cases, a Z-Wave switch may appear to freeze or become unresponsive during a factory reset. This can happen when the device’s internal processor gets stuck mid-reset and is unable to complete the reboot process on its own. When this occurs, the switch may stop responding to button presses, Z-Wave commands, or LED indicator changes.

This behavior is typically caused by one of the following:

A brief power fluctuation or surge during the reset process.
A delayed or partial press-and-hold of the reset sequence, causing the firmware to hang.
Internal memory or communication errors while the device is wiping and reinitializing its configuration.

When the switch freezes like this, it does not mean the device is permanently damaged. Instead, the internal microcontroller simply needs to be restarted to resume normal operation.

Turning off the power to the switch at the circuit breaker forces a full shutdown of the device, which clears the frozen state in its memory and reboots the internal processor. This is often enough to restore proper function and allow the switch to complete the reset or return to normal operation.

Issue: I Installed My New Switch and it Only Works When the Dumb Switch is On

Affected Model: ZEN32, ZEN35, ZEN71, ZEN72, ZEN73, ZEN74, ZEN75, ZEN76, ZEN77

Resolution: Check the Wiring.

Explanation: If the Zooz switch only operates correctly when the dumb switch is in a specific position, this indicates the wiring is incorrect.

Remove the Zooz switch from the installation immediately to prevent damage to the switch.
Restore the fully working installation with the standard mechanical switches installed.
Send us detailed images from all of the switch boxes involved in the installation. Here is a complete checklist of the kind of images our techs need in order to assist with wiring: https://www.support.getzooz.com/kb/article/263-how-can-i-identify-the-wiring-for-my-zooz-switches/
Please make sure to review the entire above article and your images before sending them to minimize back and forth emails. Please do not attempt to wire the switch without being able to match your set-up to the provided diagrams.

Issue: I Installed My New Switch and the Connected Light Rapidly Clicks On and Off

Affected Model: ZEN30, ZEN32, ZEN35, ZEN71, ZEN72, ZEN73, ZEN74, ZEN75, ZEN76, ZEN77

Resolution: Check the Wiring.

Explanation: This is immediate confirmation that the Zooz switch is incorrectly wired.

Remove the Zooz switch from the installation immediately to prevent damage to the switch.
Restore the fully working installation with the standard mechanical switches installed.
Send us detailed images from all of the switch boxes involved in the installation. Here is a complete checklist of the kind of images our techs need in order to assist with wiring: https://www.support.getzooz.com/kb/article/263-how-can-i-identify-the-wiring-for-my-zooz-switches/
Please make sure to review the entire above article and your images before sending them to minimize back and forth emails. Please do not attempt to wire the switch without being able to match your set-up to the provided diagrams.

Issue: I Installed My New Switch and the Connected Light Turns On and Immediately Back Off

Affected Model: ZEN30, ZEN32, ZEN35, ZEN71, ZEN72, ZEN73, ZEN74, ZEN75, ZEN76, ZEN77

Resolutions: There are various potential causes. Run through the list below:

Check the load: Ensure the connected load is supported for your switch type (listed in each product manual and also in the specific Specs doc for each model in our Knowledge Base). Also verify the connected load does not contain any built in motion sensor or photocell (dawn-to-dusk) functionality.
Check the secondary switch/es (if installed in a multi-way location): When installing any Zooz switch in a standard (non-virtual) multi-way installation, the other switches must be standard, mechanical, on/off switches. They CANNOT have any LED indicators, illuminated paddles, or dimming functionality.
Check the wiring.

Explanations: Each potential resolution above has a separate explanation included below:

If your smart switch turns off immediately after being turned on, one possible cause is that the connected load exceeds the switch’s rated capacity. Each switch is designed to handle a maximum wattage, which varies depending on the type of bulbs or fixtures being used. To resolve this, check the total wattage of the connected lights and make sure it falls within the switch’s rated specifications.
- Motion Sensor/Photocell (Dawn-to-Dusk sensors): Smart switches are designed to control standard light fixtures that do not have any built-in sensors or control logic. If a smart switch is connected to a fixture that includes a motion sensor, dusk-to-dawn (photocell) feature, or any other type of automatic control it can lead to unpredictable behavior and potential issues with both the switch and the fixture. Here’s why: Fixtures with motion or photocell sensors have internal electronics that automatically control power to the light based on environmental conditions, such as movement or ambient light levels. When a smart switch is used to control one of these fixtures, both devices are trying to manage power and lighting behavior independently. This often leads to a conflict where:
  - The light may turn on or off unexpectedly.
  - The smart switch may not respond properly to manual or automated commands.
  - The fixture may flicker or fail to stay synchronized with the switch.
  - The smart switch’s status may not accurately reflect the actual state of the light.
- In some cases, this setup can also cause excessive wear on the internal components of either the smart switch or the sensor-equipped fixture, especially if the two devices repeatedly override each other’s control logic. To ensure reliable operation, smart switches should always be connected to standard fixtures that do not include built-in motion detection, timers, photocells, or any form of automated behavior. If motion or daylight-based control is needed, it’s best to use a smart switch or sensor specifically designed for that purpose and pair it with a basic fixture.
When setting up a multi-way installation using a Zooz smart switch, such as in a 3-way or 4-way setup, it is important to use standard mechanical on/off switches—often referred to as "dumb" switches—as the secondary switches in the circuit. These are basic switches that physically open and close the electrical connection without any electronic components.
Zooz smart switches are designed to work with mechanical switches that do not require their own power source to operate. In a Zooz multi-way configuration, the secondary switch does not receive full line voltage. Instead, it communicates with the Zooz switch by sending a low-voltage signal through the neutral wire. This signal is only meant to trigger the state change in the Zooz switch and is not intended to power any additional devices.

Switches with LED indicators or built-in electronics require a constant supply of power, even if it’s just a small amount to light up the indicator. Because the secondary switch location in this setup does not provide power, these types of switches will not function properly; in some cases, they may interfere with the operation of the Zooz switch, cause unexpected behavior, or prevent the setup from working at all.

Using an electronic or illuminated switch in this type of configuration can also create a risk of damaging the smart switch or the secondary switch over time due to improper power handling.

To ensure reliable and safe operation, always use a simple, non-illuminated, mechanical on/off switch as the secondary switch in any multi-way installation that involves a Zooz smart switch.
Checking the wiring:
- Remove the Zooz switch from the installation immediately to prevent damage to the switch.
- Restore the fully working installation with the standard mechanical switches installed.
- Send us detailed images from all of the switch boxes involved in the installation. Here is a complete checklist of the kind of images our techs need in order to assist with wiring: https://www.support.getzooz.com/kb/article/263-how-can-i-identify-the-wiring-for-my-zooz-switches/
  Please make sure to review the entire above article and your images before sending them to minimize back and forth emails. Please do not attempt to wire the switch without being able to match your set-up to the provided diagrams.

Issue: I Installed My Zooz Dimmer and I'm Unable to Dim the Connected Lights

Affected Model: ZEN35, ZEN72, ZEN74, ZEN77

Resolutions: Verify the connected bulbs are dimmable bulbs. If you have confirmed, you may have mixed up the load and line connections on the dimmer.

Explanation: Smart dimmer switches rely on correct wiring to function properly. One of the most common wiring mistakes is reversing the line (incoming power) and load (wire going to the light) connections. While this may not always prevent the switch from turning the light on or off, it can lead to problems with dimming and other functions.

Here’s why:

When the line and load wires are reversed, the internal electronics in the dimmer switch may not receive the proper reference voltage needed to power the dimming circuitry or detect the load correctly. As a result, the switch might fail to dim the light, behave erratically, stay stuck at one brightness level, fail to power up, or fail to respond properly.

This happens because smart dimmers are designed to control the flow of power from the line side to the load side. When the wiring is reversed, the switch no longer has proper control over the electrical path, and certain features—especially dimming—may not function as expected.

Remove the Zooz switch from the installation immediately to prevent damage to the switch.
Restore the fully working installation with the standard mechanical switches installed.
Send us detailed images from all of the switch boxes involved in the installation. Here is a complete checklist of the kind of images our techs need in order to assist with wiring: https://www.support.getzooz.com/kb/article/263-how-can-i-identify-the-wiring-for-my-zooz-switches/
Please make sure to review the entire above article and your images before sending them to minimize back and forth emails. Please do not attempt to wire the switch without being able to match your set-up to the provided diagrams.

Questions? Please reach out to our support team!