Tempstar 40VA Transformer for TDE050B12A1 — 115V to 24V Control Transformer | Ships Today

Overview

This is the genuine OEM 40VA control transformer (part #1011626) for the Tempstar TDE050B12A1 gas furnace. It steps line voltage (115V) down to 24V to power the thermostat, control board, gas valve, and relays. The 40VA rating supplies enough current for the furnace's low-voltage control circuit. When a transformer fails — commonly from a shorted thermostat wire or a stuck relay — the thermostat goes blank, the furnace ignores a heat call, and there is no 24V present at the control board. A blown transformer is a frequent cause of a completely dead control circuit.

Specifications

Compatibility

Directly fits the Tempstar TDE050B12A1 gas furnace and is shared across many ICP-family units (Heil, Comfortmaker, Day & Night, Arcoaire) using the same 24V control platform. Verify the part number and VA rating before ordering.

Installation Guide

1. Safety First — Disconnect power at the switch and breaker. Verify zero voltage with a multimeter.
2. Access — Remove the furnace control-compartment service panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Disconnect the wiring, remove the mounting screws, and take out the failed transformer.
5. Install — Mount the new transformer, then reconnect the 115V primary and 24V secondary leads exactly per your photo.
6. Test — Restore power and confirm 24V across the secondary and normal thermostat/board operation.

Signs You Need a Replacement

• Blank thermostat with no 24V at the control board
• Furnace fails to respond to a heat call
• Tripped or repeatedly blown low-voltage fuse
• Burnt smell or visible scorching on the transformer

Shipping & Returns

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