Door Alarm Sensor, PIR & Vibration
Home Alarm Sensor Types (2026)

Where sensors fit in a home alarm

Every alarm is built from the same three parts. Our home alarm system guide describes them as sensors that notice something happening, a panel or hub that receives their signal, and an output such as a siren or an app notification. That guide covers the choice of system, the monitoring options and the legal points; this page is only about the first part, the sensors, because that is where most of the planning decisions sit.

Each sensor is assigned to a zone on the panel. When it triggers, the panel knows which door, window or room it was. Sensors also come in two families: wired sensors cabled back to the panel, and wireless sensors with their own battery that talk to the hub by radio. Wireless sensors usually have to be the same brand and system as the hub, so the sensor choice is tied to the panel you already have or plan to buy.

Indoor sensors are the subject here. Sensors for the garden, the boundary wall and the gate are a different set of products, covered in our outdoor and perimeter alarm sensor guide.

The main indoor sensor types compared

Five sensor types cover almost every Malaysian house, condo and shoplot. They differ in what they detect and, just as important, in when they detect it: before the intruder is inside, or after.

A good layout layers them. Contacts and vibration sensors catch the attempt at the opening; motion sensors are the second net in case the first is bypassed, for example through a roof or a wall.

Door and window contacts

The door alarm sensor is the workhorse of every system. It has two parts: the sensor body on the frame and a magnet on the moving door or window. While the two sit together the zone reads closed; when the door opens and the magnet moves away, the zone reads open and the panel reacts if it is armed.

• Surface contacts stick or screw onto the frame. They are quick to fit on a finished house and are the usual choice for wireless kits.
• Recessed (concealed) contacts are drilled into the frame and door edge so they are hidden. They are neater and harder to tamper with, but are easiest to fit during a renovation, before doors are painted.
• Heavy-duty contacts are built for roller shutters, gates and steel doors, where an ordinary contact would be knocked off.

A contact only works if the door closes the same way every time. A door that has dropped on its hinges, a sliding panel with worn rollers or a window that does not latch will let the magnet drift, and the zone then flickers open and closed. Our alarm false alarm guide explains why fixing the door is often the real repair.

Stand-alone “Wi-Fi door sensors” sold for smart-home apps work the same way but report to a phone app rather than an alarm panel. They are useful for knowing a door was opened; they are not a substitute for an armed alarm with a siren.

PIR motion sensors and pets

A passive infrared (PIR) motion sensor does not send out any beam. It watches the heat pattern of the room through a segmented lens and triggers when a warm shape moves across those segments. That makes it good at catching a person walking through a room and poor at catching someone who stays outside it.

Where it goes matters more than which model it is. Mount it in a corner so a person has to walk across its view rather than straight towards it, cover the route an intruder must take, such as the hallway to the bedrooms or the bottom of the staircase, and keep it away from aircon vents, windows in direct sun and curtains that move.

Cats and dogs are the classic problem. Pet-tolerant PIRs exist, but they only ignore pets when mounted at the height and angle the maker specifies, and they cannot help when a cat jumps onto a cabinet in the middle of the view. In rooms the pets use, contacts on the doors and windows are often a better choice than a motion sensor.

Dual-technology sensors combine PIR with a second detection method and only trigger when both agree. They cost more but are steadier in difficult rooms, such as a kitchen with a cooker hood or a store room that gets hot in the afternoon.

Vibration, shock and glass-break sensors

Contacts react when a door opens; vibration and glass-break sensors react to the attempt. That earlier warning is why they suit the openings a burglar is most likely to force.

• Vibration or shock sensors sit on a frame, a grille, a window or a safe and react to the jolts of prying, drilling or hammering. Sensitivity has to be set so that a passing lorry or a slammed door does not count.
• Glass-break sensors listen for the particular sound of glass shattering, or feel the shock on the pane. One acoustic sensor can cover several panes in one room, which suits a living room with a wide sliding glass door.
• Combined contacts put a magnetic contact and a shock sensor in one housing, so a single device covers opening and forcing on the same window.

Glass is often the weak point in Malaysian terrace houses with glass sliding doors to the back yard. Our security window film guide covers the physical side: film slows a break-in, and a glass-break sensor makes sure the attempt is noticed.

Which sensor for which door, window and room

A practical layout for a landed house or condo usually looks like this. Treat it as a starting point; the number of sensors depends on how many openings you have and how the household moves at night.

Many households arm only the doors and windows at night, so people can move around inside, and arm everything when the house is empty. Planning the zones that way from the start makes that split simple on the keypad. For the wider plan, from grilles to lighting, see our burglar-proofing checklist.

Placement mistakes that cause trouble

1. A motion sensor facing a window, so sunlight or headlights sweep across its view.
2. A motion sensor above an aircon unit, fan or curtain, where moving air and fabric look like movement.
3. A contact on a door or window that does not shut firmly, so the magnet drifts.
4. A vibration sensor set so sensitive that a door slamming in the next room triggers it.
5. A wireless sensor placed behind a steel door or a thick concrete wall from the hub, with a weak radio link.
6. Sensors that cannot be reached to clean; dust and spiders on a lens cause missed detections and false alarms.

Pairing alarm zones with cameras lets you check an alert before reacting. Our CCTV camera placement guide covers where cameras sit on a landed house so they and the sensors watch the same weak points.

Wired or wireless sensors

Wired sensors need no batteries and are hard to jam, but every one needs a cable back to the panel. That is easy while walls and ceilings are open during a renovation and messy afterwards. Wireless sensors go up quickly on a finished, occupied house, but each one has a battery to check and needs a good radio link to the hub.

Most panels accept both, so a common answer is wired contacts on the doors that were reachable during the renovation and wireless sensors for the rest. The parent guide notes that a wireless hub or any sensor that talks to its hub by radio is very likely inside MCMC's certification scheme, so check the label on wireless parts; the details are in the home alarm guide linked above. Smart-home hubs that also take door and motion sensors are covered in our smart home installation guide.

What extra sensors cost

Sensors are priced per piece, so adding coverage to an existing system is mostly a matter of counting openings. These are one Malaysian reseller's shelf prices for wireless components, as quoted in ClickBina's home alarm guide (retail price, 2026); they are hardware only, not an installed job, and one seller's prices rather than a market average.

The total for a job depends on how many doors and windows need a contact, how many rooms need a motion sensor, whether the panel has spare zones, and whether cabling can be hidden. If the panel is full, an expansion module or a larger panel may be needed before more sensors can be added.

When a sensor keeps triggering

A sensor that sets the alarm off for no reason is usually in the wrong place or on a door that does not close properly, rather than faulty. The panel's event log shows which zone triggered and when, and the pattern points at the cause: the same zone every night with a cat at home, the same window on windy days, or a wireless zone that also reports a low battery. The step-by-step fixes are in our false alarm guide linked above.

Shops and clinics often add a manual trigger to the same panel: see our panic button alarm guide for hold-up and duress buttons.

How ClickBina can help

WhatsApp us your job details for a quote: the house type, the alarm brand if you already have one, whether it is wired or wireless, and which doors, windows and rooms you want covered. ClickBina is an experienced KL & Selangor contractor for whole-house refurbishment and trade coordination, so sensor cabling can be planned while ceilings and walls are open during a renovation. We reply within the hour, and the price we agree is a flat price with no hidden charges.

Sources & methodology

• ClickBina home alarm false alarm guide — contacts drifting on badly closing doors, pets and motion sensors, event logs.
• ClickBina home alarm system guide — the three parts of an alarm, common sensor types, wired vs wireless, MCMC labels for wireless parts, and single-seller component prices.
• ClickBina outdoor and perimeter alarm sensor guide — the outdoor sensor types this page leaves out.
• How we priced it: every RM figure is quoted unchanged from ClickBina's home alarm guide, which publishes them as one reseller's 2026 shelf prices, not installed rates.