The Top 3 Reed Switches for Security Alarms

Reed switches are one of the most important parts of a well-designed security alarm system. While motion detectors monitor movement inside a property, reed switches protect the perimeter by detecting when doors, windows, roller shutters, gates or access points are opened.

For homes, offices, warehouses, retail shops and commercial premises, reed switches provide reliable entry-point protection and can help trigger the alarm before an intruder moves further inside the building.

At CTC Communications, we supply a range of reed switches for security alarm systems, including recessed, surface mount and heavy-duty roller shutter options for residential and commercial alarm installations.

What Is a Reed Switch?

A reed switch is a magnetic contact used to detect whether a door, window or other entry point is open or closed. It usually consists of two parts: a switch and a magnet. One part is fitted to the frame, while the other is fitted to the moving door, window or shutter.

When the door or window is closed, the magnet sits close to the switch and the alarm circuit remains normal. When the door or window opens, the magnet moves away, the circuit changes state and the alarm panel can register the event.

Because reed switches use magnetic contact rather than a mechanical push button, they are:

• Reliable and long-lasting
• Discreet when installed correctly
• Suitable for doors, windows, gates and roller shutters
• Useful for perimeter protection
• Compatible with many wired and wireless alarm systems
• Ideal for homes, shops, offices and commercial sites

Why Reed Switches Are Important for Security Alarms

Reed switches form an important first line of defence. Instead of waiting for an intruder to walk past a motion detector, a reed switch can detect the opening of a protected door, window or roller shutter.

This makes reed switches especially useful for:

• Front doors
• Back doors
• Sliding doors
• Garage internal access doors
• Ground-floor windows
• Roller shutters and warehouse doors
• Gates and external access points
• Commercial entry doors

Reed switches are also helpful for pet-friendly alarm designs. In some homes, protecting doors and windows with reed switches can reduce the need to rely only on internal motion detectors in areas where pets move around.

Top 3 Reed Switches for Security Alarms

The best reed switch depends on where it is being installed. A recessed reed switch may be ideal for a clean finish on a front door, while a heavy-duty roller shutter reed switch is better suited to industrial doors or commercial shutters.

1. Sentrol 1125W-N Mini 3/8 Wide Recessed Press Fit Reed Switch

The Sentrol 1125W-N Mini 3/8 Wide Recessed Press Fit Reed Switch is ideal for discreet alarm installations where appearance matters. It is designed to be recessed into a door or window frame, helping provide clean perimeter protection without visible surface hardware.

This type of reed switch is commonly used for residential alarm systems, new builds, renovations and commercial fit-outs where a neat finish is preferred.

Best suited to:

• Front doors
• Internal garage access doors
• Timber or suitable framed windows
• New builds and renovations
• Installations where a concealed finish is preferred

Key benefits:

• Compact recessed design
• Discreet installation
• Suitable for clean residential and commercial finishes
• Reliable magnetic contact detection
• Good option for perimeter alarm protection

2. Heavy-Duty Roller Shutter Reed Switch

Heavy-duty roller shutter reed switches are designed for tougher environments where standard door and window contacts may not be suitable. They are commonly used on roller doors, warehouse shutters, commercial doors and high-traffic access points.

For industrial and commercial properties, roller doors are often one of the most important areas to protect. A heavy-duty reed switch can detect when the roller door or shutter is opened and report the event through the alarm system.

Best suited to:

• Warehouse roller doors
• Commercial shutters
• Loading bays
• Industrial access points
• Factory doors
• Storage facilities
• Large garage doors

Key benefits:

• Designed for demanding environments
• Suitable for larger doors and shutters
• Strong and durable construction
• Useful for commercial and industrial alarm systems
• Helps protect high-risk entry points

3. Standard Surface Mount Reed Switch

The standard surface mount reed switch is one of the most common magnetic contacts used in alarm installations. It is fitted to the surface of the door, window or frame, making it a practical choice for existing properties where recessed installation may not be suitable.

Surface mount reed switches are often available in different colours, such as white, brown or grey, helping them blend in with different door and window frames.

Best suited to:

• Existing homes
• Office doors
• Small business premises
• Windows and entry doors
• Alarm upgrades
• Retrofit installations

Key benefits:

• Easy surface mount installation
• Suitable for retrofit alarm projects
• Available in multiple colours
• Reliable entry-point protection
• Cost-effective alarm accessory

Wired vs Wireless Reed Switches

Reed switches are available in both wired and wireless options. The right choice depends on your alarm system, property layout and whether cabling is practical.

Wired Reed Switches

Wired reed switches are hardwired back to the alarm panel or zone expander. They are often preferred for new builds, renovations and permanent alarm installations because they provide reliable long-term operation and do not rely on sensor batteries.

Wired reed switches are a strong option for:

• New homes
• Renovations
• Commercial alarm systems
• Warehouses and industrial buildings
• Properties where cabling can be installed neatly

Wireless Reed Switches

Wireless reed switches can be useful for existing homes and businesses where running new cables is difficult. They are commonly used with compatible wireless alarm systems and can be a practical solution for doors and windows that need extra protection.

Wireless reed switches are a good option for:

• Existing homes
• Apartments and townhouses
• Rental properties where cabling may be limited
• Finished properties where a retrofit is required
• Compatible wireless alarm systems

Not sure which option suits your alarm system? Read our guide: Comparison Between Wired and Wireless Reed Switches.

Where Should Reed Switches Be Installed?

Reed switches should be installed on the entry points that are most likely to be used during a break-in. For homes, this often includes the front door, rear sliding door, garage access door and selected windows. For businesses, it may include shopfront doors, roller shutters, warehouse doors and restricted access points.

Common installation locations include:

• Front entry doors
• Rear doors and sliding doors
• Garage internal access doors
• Ground-floor windows
• Roller shutters
• Warehouse roller doors
• Office entry doors
• Retail shopfront doors
• Gates and external access points

Reed Switches and Pet-Friendly Alarm Systems

Reed switches can be very useful in homes with pets. Instead of relying only on internal motion detectors, a security system can use reed switches to protect doors and windows while allowing pets to move around selected areas of the home.

This can help reduce false alarms caused by pets moving through rooms, jumping on furniture or entering areas covered by motion detectors. For the best result, reed switches should be combined with careful alarm design and suitable pet-friendly alarm options.

Reed Switches for Homes vs Businesses

Homes and businesses often use reed switches differently. A home may only need selected perimeter protection, while a business may require reed switches across multiple doors, roller shutters, restricted areas and storage zones.

Professional Installation Is Recommended

Although reed switches look simple, correct installation matters. Poor alignment, unsuitable mounting surfaces or incorrect wiring can cause false alarms, unreliable operation or missed alarm events.

A professional installer can help with:

• Choosing the correct reed switch type
• Checking compatibility with the alarm panel
• Positioning the magnet and switch correctly
• Wiring or pairing the device correctly
• Programming the correct alarm zone
• Testing each protected entry point
• Integrating reed switches with app control or monitoring where supported

Why Choose CTC Communications for Reed Switches?

CTC Communications supplies quality alarm accessories for homes, businesses and commercial security systems. Whether you are upgrading an existing alarm, replacing faulty contacts or planning a new installation, our team can help recommend suitable reed switch options for your security system.

Reasons to choose CTC Communications:

• Over 30 years of security industry experience
• Reed switches and alarm accessories for residential and commercial systems
• Compatible options for leading alarm brands and installation types
• Australia-wide delivery
• Professional installation available across Sydney
• Support for wired, wireless and hybrid alarm systems

Our Recommendation

For a clean finish on doors and windows, a recessed reed switch is often the best option. For roller shutters, warehouses and commercial doors, a heavy-duty reed switch is usually more suitable. For existing homes and simple alarm upgrades, a standard surface mount reed switch is a practical and cost-effective choice.

If you are unsure which reed switch is right for your alarm system, check your alarm panel compatibility or speak with CTC Communications before ordering.

Frequently Asked Questions