By: RTI | Version: 1.02 | Updated: April 10, 2026
Driver Instructions
This driver controls tekmar thermostats over RS-232 via the tN4 Gateway 482.
Version History: v1.00 Initial release. v1.01 Fixes an issue with setting setpoints in Celsius. v1.02 Fixes humidity control commands.
Built and tested using a 482 as well as 546 and 538 thermostats in a system including a Reset Module 423 and a Dual Zone Manager 337.
IMPORTANT: The tekmar HVAC system is a sophisticated building control system and successful integration requires extensive knowledge. If you have never used tekmar before you will need the help of the tekmar installer to understand its set up and operation.
The address shown on the thermostat is rarely the address entered into the driver. The driver supports up to 32 thermostats.
Note: The baud rate of the tekmar bus is extremely slow - there can be considerable lag between changes and when they show up. At power up it can take several minutes for initial thermostat variable data to appear.