Tempstar 40VA Transformer for TNE050B12G1 — 115V to 24V | Ships Today
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Overview
The Tempstar 1012722 is a genuine OEM control transformer that steps 115V line voltage down to 24V at 40VA for the TNE050B12G1 furnace. This 24V output powers the control board, thermostat, gas valve, and relays — essentially the entire low-voltage control circuit. When the transformer fails, the furnace loses all control power: the thermostat goes blank or unresponsive, the control board shows no activity, and the unit will not start a heat or fan cycle. Transformers commonly fail from a low-voltage short (a pinched 24V wire or shorted gas valve), repeated overloading, or simple age-related winding breakdown. A blown transformer often gives off a burnt smell and may show a melted or discolored housing. Replacing it with the correct 40VA OEM unit restores stable control power and full system operation.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1012722 |
| Type | Control transformer |
| Brand | Tempstar (ICP / Heil / Comfortmaker compatible) |
| Primary Voltage | 115V |
| Secondary Voltage | 24V |
| Rating | 40VA |
| Fitment | OEM direct replacement |
Compatibility
This transformer is a direct OEM fit for the Tempstar TNE050B12G1 furnace and is used across many ICP-built Tempstar, Heil, and Comfortmaker units requiring 115V-to-24V 40VA control power. Verify your primary input is 115V and the VA rating matches before installing.
Installation Guide
- Safety First — Disconnect power at the switch and breaker, then verify zero voltage at the primary leads with a multimeter.
- Access — Remove the furnace control/electrical service panel.
- Document — Photograph all primary (line) and secondary (24V) wire connections before disconnecting.
- Remove — Disconnect the primary and secondary leads, then unbolt the old transformer from its mounting bracket.
- Install — Mount the new 40VA transformer, reconnect 115V primary and 24V secondary leads exactly per your photo, and confirm no shorts to chassis.
- Test — Restore power and verify 24V output at the secondary and that the thermostat and control board power up.
Signs You Need a Replacement
- Blank or dead thermostat and no control board activity
- Furnace will not start any heat or fan cycle
- Burnt smell or melted/discolored transformer housing
- No 24V reading at the secondary terminals
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day hassle-free returns. Backed by the National HVAC Parts fitment guarantee.
Shipping Information
- Orders placed before 3PM CST ship same business day
- Standard delivery: 2-5 business days
- Express shipping available at checkout
- Free shipping on orders over $75
- Tracking number emailed upon shipment
Return Policy
- 30-day returns on unused parts in original packaging
- Electrical parts (capacitors, contactors, control boards) are final sale once installed
- Email info@nationalhvacparts.com to initiate a return
- Refunds processed within 5-7 business days