Tempstar 40VA Transformer for TNK050F12A1 — 115V to 24V | Ships Today

Overview

This genuine OEM control transformer (part #1011626) supplies the 24V low-voltage power for the Tempstar TNK050F12A1 furnace. It steps the 115V line-voltage primary down to a 24V secondary rated at 40VA, energizing the control board, thermostat circuit, gas valve, and relays. When the transformer fails the entire control system goes dead — the thermostat display may go blank, the furnace won't respond to a call for heat, and you'll read 0V on the 24V (R-to-C) terminals. A shorted gas valve, pinched thermostat wire, or grounded control can overload and burn out the transformer, so always find and correct the cause of a failure before installing the replacement.

Specifications

Compatibility

Designed for the Tempstar TNK050F12A1 and shared across many ICP, Heil, and Comfortmaker furnaces that use a 115V-to-24V 40VA control transformer. Verify the primary voltage, VA rating, and mounting footprint match your existing unit before installing.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage with a multimeter on both primary and secondary leads.
2. Access — Remove the furnace control-compartment service panel.
3. Document — Photograph the primary (line) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the leads, remove the mounting screws, and lift out the failed transformer.
5. Install — Mount the new transformer, connect 115V to the primary and 24V leads to the secondary exactly per your photo.
6. Test — Restore power and confirm 24V across the R and C terminals, then run a full heat cycle.

Signs You Need a Replacement

• Furnace completely unresponsive on a call for heat
• Thermostat display blank (no 24V power)
• 0V measured across the 24V R-to-C terminals
• Burnt smell or scorched transformer housing

Shipping & Returns

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