ICP Transformer for RH5420422 — 40VA 208/240V to 24V | Ships Today

Overview

This OEM control transformer (part #1540372) converts line voltage to the 24-volt control power used by the thermostat, contactor coil, gas valve, and control board on your ICP RH5420422 system. It is rated 40VA with a 208/240V primary and a 24V secondary. The transformer is the heart of the low-voltage circuit — if it fails, nothing in the control system can energize. Symptoms of a failed transformer include a blank thermostat, a contactor that never pulls in, repeated blown control fuses, and a transformer body that buzzes, runs hot, or shows scorch marks.

Specifications

Compatibility

Designed as a direct OEM fit for the ICP / Tempstar / Heil model RH5420422 and other ICP-family equipment that uses the 40VA 208/240V-to-24V control transformer. Confirm the VA and voltage ratings stamped on the original before installing.

Installation Guide

1. Safety First — Disconnect power at the breaker and verify zero voltage at the unit with a multimeter before handling any wiring.
2. Access — Remove the service panel to reach the control compartment and existing transformer.
3. Document — Photograph every primary and secondary connection before disconnecting.
4. Remove — Label and disconnect the primary (line) and secondary (24V) leads, then unbolt the failed transformer.
5. Install — Mount the new transformer and reconnect the correct primary tap (208V or 240V) and 24V secondary leads as photographed.
6. Test — Restore power and confirm 24V across the secondary and normal system operation.

Signs You Need a Replacement

• Blank thermostat and a completely dead control circuit.
• Buzzing or humming coming from the transformer.
• Repeatedly blown low-voltage control fuses.
• No 24V at the secondary terminals or visible burning on the housing.

Shipping & Returns

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