ICP Transformer for WAHM424A1 — 208/230V to 24V 40VA | Ships Today
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Overview
This OEM control transformer (part number 1172028) steps down line voltage of 208/230V to the 24V control voltage required by your ICP WAHM424A1 air handler's low-voltage circuit. Rated at 40VA, it powers the thermostat, relays, control board, and contactor coils. When a transformer fails, the system loses all 24V control power — the blower won't start, the thermostat goes dark, and nothing responds even though line power is present. A buzzing transformer, a tripped internal fuse link, or a melted secondary winding are all signs of failure, often caused by a shorted control wire or a seized blower motor drawing excess current.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1172028 |
| Type | Control / Class 2 Transformer |
| Brand | ICP (Tempstar / Heil / Comfortmaker) |
| Primary Voltage | 208/230V |
| Secondary Voltage | 24V |
| Rating | 40VA |
| Fits Model | WAHM424A1 |
Compatibility
Direct OEM replacement for the ICP WAHM424A1 air handler and matching Tempstar, Heil, and Comfortmaker variants that share the same 208/230V platform. Always confirm your existing transformer is rated 40VA at 208/230V primary to 24V secondary before installing.
Installation Guide
- Safety First — Disconnect power at the breaker and verify zero voltage at the unit with a multimeter before touching any wiring.
- Access — Remove the air handler service panel to expose the control compartment.
- Document — Photograph all primary and secondary wire connections before disconnecting anything.
- Remove — Label and disconnect the primary (line) and secondary (24V) leads, then unbolt the failed transformer from its mounting bracket.
- Install — Mount the new transformer, reconnect the primary leads to line voltage and the secondary leads to the 24V control circuit exactly per your photo.
- Test — Restore power and confirm 24V across the secondary terminals and normal system startup.
Signs You Need a Replacement
- No 24V control power — thermostat is blank and blower won't energize
- Audible buzzing or humming from the transformer
- Burnt smell or visibly scorched windings
- Repeatedly blown control fuse after reset
Shipping & Returns
Ships same day on orders placed 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