ICP 40VA Transformer for RH5430552 — 208/240V to 24V | Ships Today

Overview

This is a genuine OEM 40VA control transformer (PN 1540372) for ICP, Tempstar, and Heil model RH5430552. It steps the 208/240V line voltage down to the 24V required by the thermostat, control board, contactor coils, and relays. At 40VA it supplies roughly 1.6 amps of 24V control current. When this transformer fails — typically from a shorted secondary, a control short, or age — the entire low-voltage circuit goes dead. Typical symptoms are a blank or unpowered thermostat, no response to any heat or cool call, a repeatedly blown low-voltage fuse, or a transformer that runs hot, buzzes, or smells burnt.

Specifications

Compatibility

Direct-fit replacement for ICP, Tempstar, and Heil model RH5430552 and equipment using the same 208/240V-to-24V control platform. Confirm the 40VA rating and primary/secondary voltages match your original transformer.

Installation Guide

1. Safety First — Disconnect power and verify zero voltage with a multimeter at the primary leads.
2. Access — Remove the control/service panel to reach the transformer.
3. Document — Photograph all primary and secondary wiring before disconnecting.
4. Remove — Disconnect the leads and unbolt the failed transformer from its bracket.
5. Install — Mount the new transformer and reconnect primary (line) and secondary (24V) leads per your photo.
6. Test — Restore power and confirm 24V across the secondary and a powered control circuit.

Signs You Need a Replacement

• Blank or completely dead thermostat
• No response to any heat or cool call
• Repeatedly blown 24V control fuse
• Transformer running hot, buzzing, or smelling burnt

Shipping & Returns

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