Aprilaire 8811 Protocol Adapter for Series 8870 Thermostats

Streamline thermostat communication and diagnostics across HVAC and building monitoring systems with the Aprilaire 8811 Protocol Adapter. This Aprilaire protocol converter provides a reliable bridge between legacy RS232 interfaces and modern RS485 networks, enabling up to 32 Series 8870 thermostats to communicate on a single bus. The 8811 ships with a 7.5V AC, 500mA power supply and DB9 connector and cable for quick installation, and connects directly to Windows-based laptops so technicians can run hardware and communications verification on-site. By converting RS232 to RS485, the adapter simplifies integration into HVAC networking, security and surveillance monitoring platforms, and building automation systems—reducing troubleshooting time and improving system uptime. Lightweight and U.S.-made, the 8811 is ideal for contractors and facilities teams who need dependable protocol translation for multi-zone thermostat deployments. Add the Aprilaire 8811 Protocol Adapter to your toolkit to speed installations, streamline diagnostics, and improve integration with your security and monitoring infrastructure — order today for faster, more reliable thermostat management.

• Simplifies troubleshooting and commissioning by letting installers connect a Windows laptop directly to Aprilaire thermostats for hardware and communication diagnostics
• Converts RS232 to RS485 to integrate Series 8870 thermostats into larger HVAC and building monitoring networks
• Includes 7.5V AC, 500mA power supply plus DB9 connector and cable for fast, out-of-the-box setup
• Supports up to 32 communicating thermostats, enabling scalable deployments across commercial and multi-zone sites
• Reduces downtime and improves maintenance workflows for security, surveillance, and building automation systems