Tempstar 40VA Transformer for TCH948GKA200 — 208/230V to 24V | Ships Today

Overview

This genuine OEM transformer (part #1170676) supplies the 24V control voltage for the Tempstar TCH948GKA200. It steps down line voltage of 208/230V to a 24V secondary rated at 40VA, powering the thermostat, control board, contactor coil, and other low-voltage components. When a transformer fails, the entire low-voltage control circuit goes dead — no thermostat display, no contactor pull-in, and no system operation. Transformers commonly fail from a shorted control circuit, a seized contactor coil drawing excess current, or age-related winding breakdown.

Specifications

Compatibility

Fits the Tempstar TCH948GKA200 and many ICP-family units (Tempstar, Heil, Comfortmaker, Arcoaire) using a 208/230V-to-24V 40VA control transformer. Confirm the existing transformer is marked 1170676 and matches your primary/secondary taps before wiring.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, and verify zero voltage with a multimeter.
2. Access — Remove the control panel cover to expose the transformer and low-voltage terminals.
3. Document — Photograph every primary and secondary lead and which tap each wire lands on.
4. Remove — Disconnect the leads, then unbolt the transformer from its mounting bracket.
5. Install — Mount the new 1170676, connect the correct primary tap (208 or 230V) and the 24V secondary leads per your photo.
6. Test — Restore power and confirm 24V across the secondary and normal system startup.

Signs You Need a Replacement

• No 24V at the thermostat or control board (blank thermostat, dead system).
• Repeatedly blown low-voltage fuse or a burnt-smelling transformer.
• Measured 0V on the secondary with line voltage present on the primary.
• Visible scorching, swelling, or melted potting on the transformer body.

Shipping & Returns

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