Tempstar 40VA Transformer for TNE125J20B1 — 115V to 24V OEM 1011626 | Ships Today

Overview

This OEM control transformer (part number 1011626) supplies the 24-volt control power for the Tempstar TNE125J20B1 furnace. It steps the 115V line voltage down to a 24V secondary and is rated at 40VA — enough to drive the control board, gas valve, thermostat circuit, and contactor/relay coils. A failed transformer is one of the most common causes of a completely dead control board: no thermostat response, no blower, and no ignition, even though line voltage is present. Transformers fail from shorted thermostat wiring, a stuck gas valve drawing excess current, or simple age and overheating.

Specifications

Compatibility

Direct OEM replacement for the Tempstar TNE125J20B1 and other ICP / Heil / Comfortmaker / Tempstar furnaces using the 1011626 40VA control transformer. Verify primary/secondary voltages and VA rating against your original before installing.

Installation Guide

1. Safety First — Disconnect power at the switch and breaker; verify zero voltage with a multimeter.
2. Access — Remove the control/burner access panel.
3. Document — Photograph all primary and secondary wire connections before disconnecting.
4. Remove — Label and disconnect the leads, then remove the transformer mounting screws.
5. Install — Mount the new transformer and reconnect the 115V primary and 24V secondary leads exactly per your photo.
6. Test — Restore power and confirm 24VAC at the secondary and normal control operation.

Signs You Need a Replacement

• Completely dead control board — no thermostat, blower, or ignition response.
• No 24VAC measured at the transformer secondary.
• Burnt smell, discoloration, or melted potting on the transformer body.
• Repeated blown low-voltage fuse on the control board.

Shipping & Returns

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