ICP 40VA Transformer for SH10012B — 120V to 24V Class 2 | Ships Today

Overview

This OEM 40VA control transformer (part number 1540352) steps 120-volt line power down to the 24-volt Class 2 control voltage that powers your ICP SH10012B furnace's thermostat, gas valve, and control circuits. Because the entire low-voltage system relies on this single component, a failed transformer leaves the unit unable to start. The 40VA capacity comfortably handles standard residential control loads. Watch for a dead thermostat, a no-start condition, a repeatedly blown low-voltage fuse, a burning smell, or a transformer that hums and runs hot — all signs of transformer failure.

Specifications

Compatibility

Direct OEM replacement for the ICP / Tempstar / Heil SH10012B and other ICP-family equipment using the 1540352 transformer. Confirm a 120V-to-24V 40VA rating on your existing part before ordering.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage at the transformer with a multimeter.
2. Access — Remove the furnace service panel to expose the control compartment.
3. Document — Photograph all primary and secondary wiring before disconnecting.
4. Remove — Label and disconnect the 120V primary and 24V secondary leads, then unbolt the old transformer from its bracket.
5. Install — Mount the new transformer and reconnect primary and secondary leads per your reference photo.
6. Test — Restore power, confirm 24V at the secondary, and verify the thermostat and gas valve respond on a call for heat.

Signs You Need a Replacement

• No power to the thermostat despite confirmed line voltage
• Control fuse blows repeatedly
• Zero volts measured across the 24V secondary
• Buzzing, overheating, or burnt-insulation odor

Shipping & Returns

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