Visonic Zone Tamper — Sensor Cover Opened or Removed

What Does This Error Mean?

A Zone Tamper warning means the cover of one of your alarm sensors (door contact, PIR motion detector, etc.) has been opened, removed, or forcefully detached. The sensor has a built-in tamper switch that triggers this alert when someone physically interferes with it.

Affected Models

Visonic PowerMax Pro
Visonic PowerMax Complete
Visonic PowerMax Express
Visonic PowerG Sensors

Common Causes

Sensor cover was opened for legitimate maintenance (battery change) and not fully re-closed
Glue or mounting has failed and the sensor has fallen off the wall, opening the cover
Attempted tampering by an intruder testing the system
Internal tamper spring has shifted out of position over time

How to Fix It

Identify the tampered zone

Your Visonic keypad will display the zone name or number that has triggered the tamper. Note it down.
Go to the sensor

Locate the physical sensor on the listed zone — it will be a door/window contact or a PIR motion detector mounted on the wall or ceiling.
Check if the cover is fully closed

Press the sensor cover firmly until you hear or feel it click into place. A partially open cover keeps the tamper switch activated.
Check if the sensor has fallen

If the sensor has dropped off the wall, reattach it properly. Use appropriate screws or fresh adhesive as recommended for the surface.
Clear the tamper on the keypad

Once the physical issue is resolved, enter your user PIN and press Disarm to acknowledge and clear the tamper condition.

When to Call a Professional

Only if you cannot identify which zone is tampered, or if re-seating the cover does not clear the warning.

Visonic Zone Tamper Warning Explained

Every Visonic sensor — door contacts, PIR detectors, glass break detectors — has a built-in tamper switch. This is a small spring-loaded button inside the sensor that presses against the cover when it is properly closed. If the cover is opened or removed, the button releases and a tamper signal is sent to the panel.

This is a security feature: it alerts you if an intruder tries to disable or interfere with your sensors before breaking in.

Most Common Cause

Changing a sensor battery and not fully re-closing the cover. After replacing a battery, press the cover firmly until it clicks — even a millimetre gap can keep the tamper switch open.

If You Cannot Find the Problem

If all your sensors appear properly mounted and closed but the tamper warning persists, the tamper switch spring inside one sensor may have shifted. A technician can inspect and replace the affected sensor.

Frequently Asked Questions

Can the alarm go into full alarm if a zone tamper is triggered?

Yes — a tamper event can trigger the alarm siren immediately (in 24-hour/instant zones) or after an entry delay, depending on how the zone is programmed. It will also alert a monitoring centre if you have one.

I changed a sensor battery and now I have a tamper warning. Why?

When you open the sensor cover to change the battery, the tamper switch activates. Simply close the cover firmly — the warning should clear automatically once the panel sees the tamper switch is no longer triggered. If it does not, try entering your code and pressing Off.