Tempstar 40VA Transformer for TDE050B12B1 — 115V to 24V Control Transformer | Ships Today

Overview

This is the genuine OEM 40VA control transformer (part #1011626) for the Tempstar TDE050B12B1 gas furnace. It steps line voltage (115V) down to 24V to power the thermostat, control board, gas valve, and relays. A 40VA rating supplies enough current for the furnace's low-voltage control circuit. When a transformer fails — often from a shorted thermostat wire or a stuck contactor — the thermostat goes blank, the furnace won't respond to a heat call, and there is no 24V at the control board. A blown transformer is a frequent cause of a completely dead control circuit.

Specifications

Compatibility

Directly fits the Tempstar TDE050B12B1 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.