Tempstar Transformer for T9MPD075F12B1 — 40VA 115V to 24V | Ships Today
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Overview
This OEM control transformer (part number 1012722) is the 24-volt power source for your Tempstar T9MPD075F12B1 gas furnace. It steps line voltage down from 115V to 24V at a 40VA rating, supplying the low-voltage power that runs the thermostat, control board, gas valve, and ignition circuit. When a transformer fails, the furnace goes completely dead on the control side: no thermostat display, no blower, no ignition sequence, and often a blown low-voltage fuse on the control board. A buzzing or scorched-smelling transformer, or one reading 0V on its secondary terminals with line voltage present on the primary, indicates it has failed and needs replacement.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1012722 |
| Type | Control Transformer |
| Brand | Tempstar (ICP / Heil) |
| Primary Voltage | 115V |
| Secondary Voltage | 24V |
| Rating | 40VA |
| Fit | OEM Direct Replacement |
Compatibility
Direct-fit replacement for the Tempstar T9MPD075F12B1 modulating gas furnace and the broader T9MPD / 9MPD furnace family built on the same ICP platform. The 115V-to-24V, 40VA configuration is shared across many Tempstar, Heil, Comfortmaker, and ICP furnaces — verify your existing transformer's voltage and VA rating before ordering.
Installation Guide
- Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter before touching any wiring.
- Access — Remove the furnace blower-compartment service panel to reach the control area.
- Document — Photograph all primary and secondary wire connections before disconnecting anything.
- Remove — Disconnect the primary (115V) and secondary (24V) leads, then unbolt the transformer from its mounting bracket.
- Install — Mount the new transformer, reconnect primary and secondary leads exactly per your photo, and confirm the leads are secure.
- Test — Restore power and confirm 24V across the secondary terminals and a normal call-for-heat sequence.
Signs You Need a Replacement
- Furnace is completely unresponsive — no thermostat power and no ignition attempt
- Repeatedly blown 3A or 5A low-voltage fuse on the control board
- 0V reading on the secondary with 115V present on the primary
- Buzzing, overheating, or a burnt-electrical smell from the transformer
Shipping & Returns
Ships same day before 3 PM CST. 30-day 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