ICP 40VA Transformer for RH5430553 — 208/240V to 24V | Ships Today

Overview

This is a genuine OEM 40VA control transformer (PN 1540372) for ICP, Tempstar, and Heil model RH5430553. It steps the 208/240V line voltage down to the 24V used by the thermostat, control board, contactor coils, and relays. At 40VA it supplies roughly 1.6 amps of 24V control current. When a transformer fails — usually from a shorted secondary, a control short, or simple 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 blown low-voltage fuse on the board, or a transformer that is hot, buzzing, or smells burnt.

Specifications

Compatibility

Direct-fit replacement for ICP, Tempstar, and Heil model RH5430553 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.