ICP Transformer for VNK125N20B1 — 115V to 24V 40VA | Ships Today

Overview

This is a genuine OEM control transformer (part number 1011626) for the ICP/Tempstar/Heil VNK125N20B1 gas furnace. It steps down 115-volt line voltage to the 24-volt control circuit that powers the thermostat, control board, gas valve, and relays. Rated at 40VA, it supplies the low-voltage control loads in this furnace platform. When the transformer fails, the entire 24V circuit goes dead — the thermostat screen blanks out and the furnace will not begin a heat cycle even though 115V line power is reaching the unit.

Specifications

Compatibility

Engineered as the factory replacement for the ICP/Tempstar/Heil VNK125N20B1 furnace and related Comfortmaker-family equipment using a 115V primary, 24V secondary, 40VA control transformer. Verify your existing transformer's primary/secondary voltage and VA rating against the specs above before installing.

Installation Guide

1. Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter before touching wiring.
2. Access — Remove the furnace control-compartment service panel.
3. Document — Photograph the primary (115V) and secondary (24V) wire connections before disconnecting.
4. Remove — Disconnect the primary and secondary leads, then unbolt the failed transformer from its bracket.
5. Install — Mount the new transformer and reconnect the 115V primary and 24V secondary leads per your photo.
6. Test — Restore power and verify 24V across the secondary terminals, then confirm the thermostat and gas valve energize normally.

Signs You Need a Replacement

• Blank thermostat with no 24V control power
• Furnace will not start despite 115V line power present
• No 24V reading across the transformer secondary
• Burnt odor, blown control fuse, or scorched transformer housing

Shipping & Returns

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