Tempstar PTAC Thermostat for THA09K25STC — OEM Part 1058517 | Ships Today

Overview

This is the genuine OEM PTAC thermostat (part number 1058517, TSTAT PTAC X) for the Tempstar THA09K25STC packaged terminal air conditioner / heat pump. The thermostat is the control brain of the unit — it reads room temperature and signals the compressor, fan, and heating elements to cycle on and off to maintain your setpoint. When this control fails, the unit may run continuously, fail to start, blow the wrong temperature air, or display erratic readings. Replacing it with the exact OEM control restores reliable, accurate temperature regulation without guesswork.

Specifications

Compatibility

Engineered as a direct-fit replacement for the Tempstar THA09K25STC PTAC system. This control is shared across the ICP/Heil/Tempstar THA09K family of packaged terminal units. Always confirm the OEM part number 1058517 stamped on your existing thermostat before ordering to guarantee an exact match.

Installation Guide

1. Safety First — Disconnect power to the PTAC unit at the breaker and verify zero voltage with a multimeter before touching any wiring.
2. Access — Remove the front grille and service panel to expose the control compartment.
3. Document — Photograph all wire connections and terminal positions before disconnecting anything.
4. Remove — Release the failed thermostat from its mount and disconnect the wiring harness, noting each lead position.
5. Install — Mount the new 1058517 control, then reconnect every wire exactly as shown in your photo.
6. Test — Restore power and confirm the unit cools, heats, and cycles correctly at the setpoint.

Signs You Need a Replacement

• Unit runs constantly or won't reach the setpoint temperature.
• No response when adjusting temperature or mode settings.
• Erratic, blank, or frozen display readings.
• Compressor or fan short-cycles or fails to start.

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.