Tempstar 24V Transformer for T4H342GKD200 — 40VA Control Power | Ships Today
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Overview
This is the OEM 24V control transformer for the Tempstar T4H342GKD200 heat pump, supplying the low-voltage power that drives the 24V reversing-valve coil, contactor coil, and defrost control circuit (related OEM components #1172574 Coil Rev Vlv 24V and #1175622 Valve Rev w/Coil 24V). The transformer steps line voltage (208/240V) down to a regulated 24VAC at 40VA. When a transformer fails — usually from a shorted coil or an overloaded secondary — the entire low-voltage side goes dead: the thermostat loses power, the contactor will not pull in, and the reversing valve cannot energize. A buzzing, hot, or blown transformer is a common root cause of a completely unresponsive unit.
Specifications
| Spec | Value |
|---|---|
| OEM Part Numbers | 1172574, 1175622 (associated 24V control components) |
| Type | Control / Class 2 Transformer |
| Brand | Tempstar (ICP / Heil family) |
| Rating | 40 VA |
| Primary Voltage | 208 / 240V |
| Secondary Voltage | 24V |
| Fitment | OEM Direct Replacement |
Compatibility
Direct OEM replacement for the Tempstar T4H342GKD200 heat pump and ICP-built Heil, Comfortmaker, and Carrier/Bryant private-label units sharing the same 24V control platform. Verify primary voltage taps and the 40VA rating against your existing transformer before wiring.
Installation Guide
- Safety First — Disconnect power at the breaker and disconnect, then verify zero voltage with a multimeter before touching any wiring.
- Access — Remove the control-panel/service cover to reach the transformer and low-voltage terminal block.
- Document — Photograph every primary and secondary lead and its terminal before disconnecting.
- Remove — Label and disconnect the leads, then unbolt the transformer from its mounting bracket.
- Install — Mount the new transformer, match the correct primary tap to your line voltage, and reconnect the 24V secondary per your photo.
- Test — Restore power and confirm 24VAC across the secondary; verify the thermostat, contactor, and reversing valve energize on a call.
Signs You Need a Replacement
- No 24V control power — thermostat blank or system fully unresponsive
- Contactor or reversing-valve coil will not energize
- Transformer is buzzing, hot to the touch, or visibly scorched
- Repeated low-voltage fuse blows after the transformer was loaded
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