New Trane HVAC System Installation in Leander

A homeowner in Leander reached out when their upstairs HVAC system could no longer maintain stable temperatures and was causing frequent moisture concerns in the attic drain pan. Our Radiant Austin HVAC install team replaced the outdated straight cool system with a new high-efficiency Trane two-stage setup, removed the failing zoning equipment, upgraded the thermostat controls, and cleaned all supply and return ducts throughout the home. The result was a dependable, balanced system that now supports the entire upstairs with consistent airflow and improved performance.

Job Overview

• Location: Leander, TX
• Client Type: Residential
• Scope: Full HVAC system replacement, zoning removal, thermostat upgrades, plenum replacement, whole-home duct cleaning
• Equipment Installed: Trane XR16 4-ton two-stage straight cool condenser, Trane S9X1 90% gas furnace (horizontal attic configuration), Trane evaporator coil (correct model delivered and installed on final day), New supply plenum, Ecobee smart thermostats, HALO/REME LED air purification system
• Additional Work: Removal of all zoning dampers, removal of zoning control board, media filter cabinet replacement, full supply and return duct cleaning, evaluation of furnace PVC drain piping
• Why It Mattered: The upstairs system served the entire second floor of the home. A reliable and properly sized new system restored comfort and eliminated airflow restrictions caused by outdated zoning hardware.

What We Found

The existing HVAC system had been installed a year earlier but was undersized for the demands of the full upstairs space. Multiple zoning components were restricting airflow, including circular dampers inside two supply ducts and a large damper in the plenum. The zoning board was also causing inconsistent temperature control because three thermostats were fighting each other. The homeowner suspected drainage issues, as water regularly collected in the attic drain pan. Our technician confirmed poor pitch on the furnace’s PVC drain setup and noted that the system’s limited airflow made moisture buildup more likely.

The Solution

Our installation team replaced the entire upstairs system with a new 4-ton Trane XR16 two-stage condenser and a matching Trane S9X1 90% gas furnace with a properly sized coil. Because the old equipment couldn’t fit down the attic ladder, it was safely disassembled for removal. We installed a new 6.5-foot supply plenum and reattached all seven flex ducts with proper connections. All zoning dampers and the control board were removed so the system could run as a single, balanced stage. A HALO LED air purifier was mounted inside the new plenum for improved indoor air quality.

We also installed new Ecobee thermostats – including one in the upstairs hallway as the main controller – and replaced the thermostat for the downstairs system for consistency. Finally, our team completed full duct cleaning for all three systems, including high ceilings that required a rented 14-foot ladder. After installing the correct evaporator coil, we tested both heating and cooling modes and verified proper airflow and drainage.

Photo Highlights

• A look inside the attic where the new upstairs HVAC system, drain lines, and ductwork were installed and reconfigured.
  
• The replacement supply plenum installed and sealed, providing proper airflow to all upstairs rooms.
  
• The HALO LED UV air purifier installed on the new supply plenum to reduce airborne contaminants throughout the home.
  
• A new Wet Switch flood safety device installed in the drain pan to shut off the system if moisture is detected.
  
• The upgraded Trane XR16 outdoor unit set in place and wired in, ready to support the home’s new HVAC system.
  
• Final refrigerant charge readings taken after installing the new Trane system to confirm proper cooling performance.
  

The Results

The new Trane system now delivers steady, reliable heating and cooling throughout the entire upstairs level. Removing the old zoning hardware improved airflow, reduced restrictions, and eliminated temperature swings between rooms. With the new Ecobee controls and HALO LED purifier, the homeowner benefits from better indoor air quality and more precise system management. Duct cleaning and updated drainage contributed to a healthier, more efficient system overall.

Your Trusted HVAC Installation Experts in Leander

Radiant Plumbing & Air Conditioning is proud to support homeowners throughout Leander with expert HVAC installations, system upgrades, and whole-home improvements. If you’re noticing uneven temperatures, rising energy bills, or an aging system, our team is here to help. Schedule your quote online or call to get started.