ICP 40VA Transformer for WPG4304040RKB1 — 208/230V to 24V | Ships Today

Overview

This is a genuine OEM 40VA control transformer (part number 1173691) with its 24V barrier/terminal cover (part number 1178431) for the ICP/Tempstar/Heil WPG4304040RKB1 packaged unit. The transformer steps line voltage of 208/230V down to the 24V control circuit that powers the thermostat, control board, contactor coil, and gas valve. When a transformer fails — often from a shorted low-voltage wire or a stuck contactor drawing excess current — the entire 24V control system goes dead. Symptoms include a blank thermostat, no response to heating or cooling calls, and a blown low-voltage fuse on the control board.

Specifications

Compatibility

Engineered as a direct OEM replacement for the ICP/Tempstar/Heil WPG4304040RKB1 model. Verify the 40VA rating, the 208/230V primary tap, and part numbers 1173691 and 1178431 before installing.

Installation Guide

1. Safety First — Disconnect power at the breaker and unit disconnect; verify zero voltage with a multimeter.
2. Access — Remove the control compartment service panel.
3. Document — Photograph all primary and secondary leads before disconnecting.
4. Remove — Disconnect the leads, unscrew the transformer from its mounting bracket, and clear the failed low-voltage short if present.
5. Install — Mount the new transformer, install the 24V barrier, and reconnect leads to the matching primary tap per your photo.
6. Test — Restore power, confirm 24V at the secondary, and verify the thermostat powers up.

Signs You Need a Replacement

• Blank or unresponsive thermostat
• No 24V output measured at the secondary terminals
• Repeated blown low-voltage fuses
• System dead to both heating and cooling calls

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.