Tempstar 40VA Transformer for TEB07K34RTA — 208/240V to 24V | Ships Today

Overview

This OEM 40VA control transformer steps the Tempstar TEB07K34RTA's 208/240V line voltage down to the 24V needed by the unit's low-voltage controls and relays. The replacement covers the transformer (OEM 1056899, TRANS 208/240→24 40VA) along with the 24V control relays (OEM 1053004 SPST and 1060940 DPST) that switch the compressor and fan circuits. When a control transformer fails — often from an overloaded secondary or a shorted thermostat wire — the entire 24V control circuit goes dead and the PTAC won't respond to any call for heating or cooling. A buzzing, overheated, or blown transformer is one of the most common no-power-to-controls failures.

Specifications

Compatibility

Built for the Tempstar TEB07K34RTA PTAC and shared across the ICP/Heil/Tempstar TEB07K34 series packaged terminal units. Confirm the primary voltage and VA rating against the failed transformer before installing.

Installation Guide

1. Safety First — Disconnect power at the unit and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the PTAC front cover and control-box panel.
3. Document — Photograph the primary and secondary leads and relay wiring before disconnecting.
4. Remove — Unbolt the transformer bracket, disconnect the leads, and unclip the relays.
5. Install — Mount the new transformer, match primary to line and secondary to the 24V circuit, and reconnect the relays per your photo.
6. Test — Restore power, confirm 24V across the secondary, and verify the controls and relays energize.

Signs You Need a Replacement

• No 24V power — unit completely unresponsive to thermostat calls
• Buzzing, humming, or visibly overheated transformer
• Repeatedly blown control fuse or burnt secondary winding
• Relays that won't pull in or chatter

Shipping & Returns

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