JOHNSON CONTROLS LP-XT91D00-000C Extension Expansion Module MD20

( Brand: Johnson Controls ), ( Manufacturer Part Number: LP-XT91D00-000C ), ( Part Type: Module )

Review JOHNSON CONTROLS Extension Expansion Module

The **Johnson LP-XT91D00-000C MD20 Extension Expansion Module** is a high-performance, modular solution designed to enhance the capabilities of Johnson Controls **Metasys ** building automation system, particularly for installations requiring extended reach or additional I/O connectivity. This robust expansion module is engineered to seamlessly integrate with the **MD20** series of controllers, providing critical flexibility for architects, engineers, and facility managers working with complex HVAC, lighting, security, or energy management systems. Built with precision and durability in mind, the LP-XT91D00-000C features a **long-range, high-speed communication interface** that ensures reliable data transmission over extended distances, making it ideal for large-scale facilities where traditional wiring constraints could otherwise limit system scalability. Its **compact yet rugged design** allows for easy installation in tight spaces, whether in commercial office buildings, industrial plants, or institutional environments like hospitals and universities. The module supports **Modbus RTU or RS-485 communication protocols**, enabling seamless interoperability with third-party devices and legacy systems, while its **low-power consumption** ensures energy efficiency without compromising performance. Whether deployed for **remote sensor integration, distributed control expansion, or network segmentation**, this expansion module delivers the reliability and adaptability needed to future-proof building automation infrastructure. With its **comprehensive documentation and compatibility with Johnson Controls Metasys software**, engineers can quickly configure and monitor expanded system functionality, reducing downtime and optimizing operational efficiency. Ideal for both new installations and retrofits, the LP-XT91D00-000C stands as a versatile bridge between centralized control systems and decentralized field devices, ensuring seamless communication and enhanced automation across diverse building environments.

The **Johnson LP-XT91D00-000C MD20 Extension Expansion Module** is a specialized accessory designed to extend the range of Johnson Controls' **MD20** series of wireless thermostats (such as the **MD20-100** or **MD20-101**). Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the LP-XT91D00-000C MD20 Extension Module**

1. **Extended Wireless Range**

The primary benefit is its ability to extend the wireless communication range between the thermostat and your HVAC system. This is particularly useful in larger homes, multi-story buildings, or areas with thick walls, interference, or dead zones where the thermostat struggles to maintain a stable connection.

2. **Compatibility with Johnson Controls MD20 Series**

It is specifically designed for the **MD20** line, ensuring seamless integration without compatibility issues. This reduces the risk of signal conflicts or malfunctions that could arise with generic extenders.

3. **Easy Installation**

The module is plug-and-play, requiring minimal setup. It connects via a standard electrical outlet and does not require hardwiring or professional installation, making it accessible for DIY users.

4. **Reliable Signal Boost**

Unlike generic Wi-Fi extenders or repeaters, this module is optimized for **RF (radio frequency) signals** used by Johnson Controls thermostats, providing a more stable and dedicated connection.

5. **No Additional Subscription Fees**

Unlike some smart home devices that require ongoing monthly fees, this extension module operates independently once installed.

6. **Compact and Unobtrusive Design**

The module is small and can be placed discreetly near the thermostat or HVAC system without taking up much space.

7. **Supports Multiple MD20 Devices**

If you have multiple MD20 thermostats in a large home, this module can help ensure all devices stay connected to the HVAC system without interference.

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### **Cons of the LP-XT91D00-000C MD20 Extension Module**

1. **Limited to MD20 Series Only**

It will **not** work with other Johnson Controls thermostat models (e.g., **MD200, MD2000, or earlier models like the MD80**). If you have a different thermostat, this module is useless.

2. **No Support for Advanced Features**

The module only extends the **wireless range** it does not add new functionality like smart home integrations (e.g., Alexa, Google Assistant), energy monitoring upgrades, or remote access improvements. If you need these, you may still require a compatible smart hub or gateway.

3. **Potential for Interference**

While it boosts the signal, other electronic devices (e.g., microwaves, cordless phones, or neighboring Wi-Fi networks) can still cause interference. Placement matters it should be away from sources of electromagnetic noise.

4. **Not a Permanent Fix for Poor HVAC Wiring**

If your HVAC system has **poor wiring, faulty relays, or a weak power supply**, the extension module may not resolve underlying connectivity issues. In such cases, professional HVAC inspection may be needed.

5. **Single-Outlet Dependency**

The module requires a working electrical outlet. If the outlet is damaged or lacks power, the extender will not function. Some users may need to use a power strip, but this adds another potential failure point.

6. **No Built-in Diagnostics**

Unlike some smart thermostats, this module does not provide error codes or troubleshooting tools. If it fails, you may need to rely on Johnson Controls support or trial-and-error placement.

7. **Cost Consideration**

At around **$50 $70**, it is a targeted solution. If your issue stems from something else (e.g., a faulty thermostat or HVAC component), this may not be the most cost-effective fix.

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### **Conclusion**

The **Johnson LP-XT91D00-000C MD20 Extension Module** is a **niche but highly effective solution** for users experiencing **wireless signal dropouts or dead zones** with their **MD20 series thermostats**. Its strengths lie in its **simplicity, reliability for MD20 compatibility, and ease of installation**, making it ideal for those who need a quick, plug-and-play upgrade.

However, it is **not a universal fix** it only addresses **range limitations** and does not improve other aspects of thermostat performance (e.g., smart home integration, energy tracking, or hardware reliability). If your thermostat frequently disconnects due to **HVAC wiring issues, interference, or a failing unit**, this module may provide temporary relief but not a permanent solution.

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### **Recommendation**

- You have a **Johnson Controls MD20 series thermostat** (e.g., MD20-100, MD20-101).

- You are experiencing **consistent wireless signal loss** in a large home or area with poor thermostat placement.

- You want a **simple, no-fuss solution** that does not require professional installation.

- You are willing to **test placement** (e.g., closer to the HVAC system) to maximize effectiveness.

- You have a **non-MD20 thermostat** (e.g., MD80, MD200, or other brands).

- Your thermostat **frequently disconnects due to HVAC wiring issues** consider professional inspection instead.

- You need **smart home integrations, advanced energy reports, or remote access** this module does not add those features.

- You are on a tight budget and the issue may stem from a **cheaper fix** (e.g., repositioning the thermostat or checking outlet power).

- **Repositioning the thermostat** closer to the HVAC system or away from interference sources.

- **Replacing a faulty outlet or power supply** if the module does not have reliable power.

- **Upgrading to a newer Johnson Controls thermostat** (e.g., **MD2000 series**) if your current model is outdated.

- **Using a mesh network adapter** (if available for your thermostat model) for better signal distribution.

For the right user, the **LP-XT91D00-000C is a worthwhile investment** to eliminate frustrating connectivity issues. However, it is not a one-size-fits-all solution, and its effectiveness depends on the specific circumstances of your HVAC setup. Always verify compatibility and test placement before purchasing.

Details:

Johnson Controls LP-XT91D00-000C MD20 Extension Expansion Module. Condition is Used. Shipped with USPS Ground Advantage.

part #: lpxt91d00000c prices

• $80.00-$628.02

specifications hvaapa:

• brand: Johnson Controls
• mpn: Lp-xt91d00-000c
• part type: Module

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• rating: 100.0%
• city: Sycamore, Illinois
• # reviews: 67

shipping hvaapa:

• transit: 5-11 Days
• service: USPS Ground Advantage
• type: Calculated
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• class: Standard

general hvaapa:

• condition: Used
• HVAC Refrigeration > HVAC Refrigeration: Parts Accessories > HVAC Refrigeration: Controls Circuit Boards

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• sold: 0
• started: April 10, 2026
• options: Ship-to-home
• availability: In Stock
• quantity: 1

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