Tempstar 40VA 208/240V-to-24V Transformer for TEB09K25RTA – With Relays | Ships Today
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Overview
This OEM control package powers the low-voltage circuit of the Tempstar TEB09K25RTA. The core is a 40VA control transformer (part 1056899) that steps 208/240V line voltage down to 24V to run the thermostat, relays, and contactor coils. It is paired with the unit's 24V relays — a standard 24V relay (part 1053004) and a 24V DPST relay (part 1060940) — that switch the fan and compressor loads on command. A failed transformer leaves the entire control circuit dead: no 24V means the unit won't respond at all, even though line power is present. Symptoms include a humming or burnt transformer, blown control fuse, or no low-voltage output at the secondary terminals. Worn relays cause stuck or unresponsive loads.
Specifications
| Spec | Value |
|---|---|
| Part Numbers | 1056899 (40VA Transformer), 1053004 (Relay 24V), 1060940 (Relay 24V DPST) |
| Type | Control Transformer with Relays |
| Brand | Tempstar (ICP / Heil) |
| Rating | 40 VA |
| Primary Voltage | 208 / 240V |
| Secondary Voltage | 24V |
| Relay Contacts | SPST / DPST, 24V coil |
| Fitment | OEM direct replacement |
Compatibility
Direct OEM replacement for the Tempstar TEB09K25RTA control circuit. The 40VA 208/240V-to-24V transformer and 24V relay platform are shared across ICP, Heil, Comfortmaker, and Tempstar units using the same low-voltage scheme. Verify primary voltage, VA rating, and the existing part numbers before ordering.
Installation Guide
- Safety First – Disconnect power at the unit disconnect and verify zero voltage at the transformer primary with a multimeter.
- Access – Remove the service panel to reach the control box.
- Document – Photograph the primary and secondary leads and every relay terminal before disconnecting.
- Remove – Unscrew the transformer from its mount, disconnect the primary and secondary leads, and unplug the relays.
- Install – Mount the new transformer, confirm the primary tap matches your supply voltage, reconnect secondary leads, and seat the new relays per your photos.
- Test – Restore power, measure 24V at the secondary, call for operation, and verify the relays energize and the loads respond.
Signs You Need a Replacement
- No 24V output at the transformer secondary terminals
- Unit completely unresponsive despite present line voltage
- Humming, overheating, or visibly burnt transformer
- Repeated blown control fuses or stuck/chattering relays
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