ICP 40VA Transformer for WFML135D066B1 — 120/24V OEM 1177217 | Ships Today
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Overview
This genuine OEM control transformer (part number 1177217) is the factory step-down transformer for the ICP / Heil / Tempstar WFML135D066B1 gas furnace. Rated 40VA with a 120V primary and 24V secondary, it converts incoming line voltage into the low-voltage 24V control power that runs the thermostat, gas valve, control board, and safety circuits. When a transformer fails — usually from a short, an overload, or age — the entire low-voltage control system goes dead: the thermostat screen blanks, the furnace won't respond to a call for heat, and no relays or valves energize. A fresh transformer restores reliable 24V power to the whole control circuit.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1177217 |
| Type | Step-down control transformer |
| Brand | ICP / Heil / Tempstar |
| Rating | 40 VA |
| Primary Voltage | 120 V |
| Secondary Voltage | 24 V |
| Fit | OEM exact replacement |
Compatibility
Direct factory replacement for the ICP / Heil / Tempstar / Comfortmaker WFML135D066B1 furnace and other ICP-family units using a 40VA 120V-to-24V control transformer. Confirm primary/secondary voltages and VA rating against your existing unit.
Installation Guide
- Safety First — Disconnect power at the switch and breaker, then verify zero voltage with a multimeter at both primary and secondary leads.
- Access — Remove the control/electrical compartment service panel.
- Document — Photograph every wire and terminal before disconnecting.
- Remove — Disconnect the primary (line) and secondary (24V) leads, then unbolt the transformer from its bracket.
- Install — Mount the new transformer, reconnect primary and secondary leads per your photo, and confirm a solid ground.
- Test — Restore power and measure 24V across the secondary; confirm the thermostat powers up and the furnace responds to a heat call.
Signs You Need a Replacement
- Blank thermostat / no low-voltage power
- Furnace won't respond to a call for heat
- Burnt smell or visible scorching on the transformer
- 0V reading across the 24V secondary with line voltage present
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