---
product_id: 8984151
title: "4WT-B 4-wire, photoelectric i3 smoke detector with a 135 Degree fixed thermal sensor"
brand: "system sensor"
price: "₨2033"
currency: SCR
in_stock: true
reviews_count: 8
category: "System Sensor"
url: https://www.desertcart.sc/products/8984151-4wt-b-4-wire-photoelectric-i3-smoke-detector-with-135
store_origin: SC
region: Seychelles
---

# 12/24 VDC four-wire power 135°F fixed thermal sensor Red LED visual alert 4WT-B 4-wire, photoelectric i3 smoke detector with a 135 Degree fixed thermal sensor

**Brand:** system sensor
**Price:** ₨2033
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of danger with precision detection and pro-grade reliability!

## Quick Answers

- **What is this?** 4WT-B 4-wire, photoelectric i3 smoke detector with a 135 Degree fixed thermal sensor by system sensor
- **How much does it cost?** ₨2033 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sc](https://www.desertcart.sc/products/8984151-4wt-b-4-wire-photoelectric-i3-smoke-detector-with-135)

## Best For

- system sensor enthusiasts

## Why This Product

- Trusted system sensor brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Dual Detection Power:** Photoelectric smoke sensing paired with a 135°F fixed thermal sensor for unmatched fire detection accuracy.
- • **Durable & Dependable:** Crafted in the USA with UL and CSFM certifications, designed to perform flawlessly in temperatures from 32°F to 120°F.
- • **Seamless Integration:** Four-wire design ensures reliable, hardwired power with no battery fuss—perfect for professional-grade installations.
- • **Smart Maintenance Ready:** Built-in remote maintenance signaling and drift compensation algorithms reduce false alarms and upkeep hassle.
- • **Visual Safety Assurance:** Bright red LED alerts provide instant, unmistakable visual warnings to keep your space secure.

## Overview

The System Sensor 4WT-B is a professional-grade, four-wire photoelectric smoke detector featuring a 135°F fixed thermal sensor for enhanced fire detection. Manufactured in the USA, it offers a red LED visual alert, built-in remote maintenance signaling, and advanced drift compensation to minimize false alarms. Designed for hardwired 12/24 VDC power, it meets UL and CSFM standards and operates reliably in a wide temperature range, making it an ideal upgrade for commercial and residential safety systems.

## Description

Smoke Alarm, Detection Method Photoelectric, No Interconnection Capability, Power Source 12/24 VDC, Four-Wire, Visual Alert Red LED, Diameter 5-19/64 In., Height 2 In., Digital Readout No, Battery Backup No, Features Removable Detector Cover and Chamber, Built-In Remote Maintenance Signaling, Drift Compensation and Smoothing Algorithms, Thermal Sensor, Hush Button No, Locking Pin No, Operating Temp. 32 Degrees to 120 Degrees F, Standards UL, CSFM, Includes Base

Review: Great replacement for a 4 wire smoke detector - Replaced an older 4 wire smoke detector that had yellowed over time. Works perfectly and has the added capability of fixed rate heat detection.
Review: Installation of System Sensor 4 WT-B - Perfect replacement for System Sensor model # 2112/24TS 4-wire PhotoElectronic smoke detector. Easily removed old unit and rewired the new unit by connecting red wire to + in terminal, single black wire to - in/out terminal, two black wires to no terminal and green and white wires to com terminal. Tested the newly installed unit by inserting allen wrench into recessed test switch and applied heat from a hair dryer. Both test sounded the alarm. Unit is correctly wired and installed when the green LED light is blinking.

## Features

- Smoke Alarm
- Country of manufacture: United States

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0015QE0HM |
| Alarm | Visual |
| Best Sellers Rank | #96,580 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #114 in Smoke Detectors & Fire Alarms |
| Brand | System Sensor |
| Built-In Media | Unit^Instruction Guide |
| Color | White |
| Customer Reviews | 4.6 out of 5 stars 137 Reviews |
| Item Dimensions D x W x H | 2.4"D x 5.7"W x 5.7"H |
| Item Weight | 0.51 Pounds |
| Manufacturer | System Sensor |
| Model Number | 4WT-B |
| Power Source | Corded Electric |
| Product Dimensions | 2.4"D x 5.7"W x 5.7"H |
| Product Style | Smoke Detector |
| Sensor Type | Photoelectric |
| Style | Smoke Detector |
| UPC | 783863017629 |
| Unit Count | 1.0 Count |
| Upper Temperature Rating | 135 Degrees Fahrenheit |

## Product Details

- **Brand:** System Sensor
- **Style:** Smoke Detector
- **Power Source:** Corded Electric
- **Color:** White
- **Product Dimensions:** 2.4"D x 5.7"W x 5.7"H
- **Item Weight:** 8.16 ounces
- **Alarm:** Visual
- **Upper Temperature Rating:** 135 Degrees Fahrenheit
- **Sensor Type:** Photoelectric
- **Number of Items:** 1

## Images

![4WT-B 4-wire, photoelectric i3 smoke detector with a 135 Degree fixed thermal sensor - Image 1](https://m.media-amazon.com/images/I/41TZQsLVDtL.jpg)

## Questions & Answers

**Q: Es necesario colocar una base? el sistema estará conectado al sistema de alarmas**
A: Hello,
Please submit your question in English.

**Q: Is this the update to replace model 2412?**
A: i never used 2412 unit but 4wt-b-4 should work as a replacement it is 12vdc & 2 wires to trigger alarm

**Q: I have an old unit that needs replacing. There is a 4 wire phone cord like coming out of the cieling....red/black/green and yellow, Will this work?**
A: Check the website for System Sensor to check the replacement for the original unit.

**Q: Will this mount onto a standard round ceiling box?  saw a review/complaint about detector having no base.  i'm just replacing a bad esl smoke detector**
A: It comes with new round plastic base plates in the box, but I just used the old ones that were already installed.  So I just twist-locked the new sensor into the old plastic base plate.  If the light does not come up green after installing, try resetting your whole system.  My alarm contractor had to install a resistor or something to get all the sensors to switch to green.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great replacement for a 4 wire smoke detector
*by M***E on November 4, 2025*

Replaced an older 4 wire smoke detector that had yellowed over time. Works perfectly and has the added capability of fixed rate heat detection.

### ⭐⭐⭐⭐⭐ Installation of System Sensor 4 WT-B
*by A***R on August 11, 2025*

Perfect replacement for System Sensor model # 2112/24TS 4-wire PhotoElectronic smoke detector. Easily removed old unit and rewired the new unit by connecting red wire to + in terminal, single black wire to - in/out terminal, two black wires to no terminal and green and white wires to com terminal. Tested the newly installed unit by inserting allen wrench into recessed test switch and applied heat from a hair dryer. Both test sounded the alarm. Unit is correctly wired and installed when the green LED light is blinking.

### ⭐⭐⭐⭐⭐ Perfect swap- No issues
*by B***Y on June 26, 2025*

Exact replacement for my unit. Left original base plate and added new sensor. Alarm system recognized and all is working.

## Frequently Bought Together

- System Sensor 4WT-B 4-wire, photoelectric i3 smoke detector with a 135 Degree fixed thermal sensor
- IS335 WIRED PIR Motion Detector, 40' x 56' by Honeywell
- Honeywell Security 6160 Ademco Alpha Display Keypad

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.sc/products/8984151-4wt-b-4-wire-photoelectric-i3-smoke-detector-with-135](https://www.desertcart.sc/products/8984151-4wt-b-4-wire-photoelectric-i3-smoke-detector-with-135)

---

*Product available on Desertcart Seychelles*
*Store origin: SC*
*Last updated: 2026-02-21*