Tempstar 40VA Transformer for T8MPV050B12A1 — 115V to 24V | Ships Today

Overview

This OEM control transformer (part #1012722) converts 115-volt line power into the 24-volt control voltage that runs the low-voltage circuit on your Tempstar T8MPV050B12A1 furnace. Rated at 40VA, it supplies the thermostat, control board, gas valve, and relays. When the transformer fails, the control circuit loses power entirely: the thermostat goes blank, the furnace ignores heat and cool calls, and the board's low-voltage fuse may blow repeatedly. Buzzing, overheating, or a burnt smell at the transformer are classic warning signs. This genuine OEM Class 2 transformer matches the exact voltage, VA rating, and mounting of your unit so the control circuit comes right back to life.

Specifications

Compatibility

Made for the Tempstar T8MPV050B12A1 gas furnace and used across ICP-family equipment (Heil, Comfortmaker, Arcoaire) that requires a 115V-to-24V 40VA control transformer. Verify your existing transformer is 115V primary / 24V secondary / 40VA before installing.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the furnace control/blower compartment service panel.
3. Document — Photograph the primary (line) and secondary (24V) wiring before disconnecting.
4. Remove — Disconnect the leads, remove the mounting screws, and lift out the failed transformer.
5. Install — Mount the new transformer and reconnect primary and secondary leads exactly as photographed.
6. Test — Restore power, confirm 24VAC across the secondary, and verify the furnace responds to a thermostat call.

Signs You Need a Replacement

• Blank thermostat with no furnace response
• Repeatedly blown low-voltage control fuse
• Buzzing or burnt-electrical smell at the transformer
• No 24VAC reading at the secondary terminals

Shipping & Returns

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