What are the specs for this Transformer?

The correct replacement for ICP model X9MPT125L20B1 — 40VA 115V to 24V | Ships Today is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your ICP equipment which lists the model number X9MPT125L20B1 — 40VA 115V to 24V | Ships Today.

ICP

ICP Step-Down Transformer for X9MPT125L20B1 — 40VA 115V to 24V | Ships Today

Name: ICP Step-Down Transformer for X9MPT125L20B1 — 40VA 115V to 24V | Ships Today
Brand: ICP
SKU: X9MPT125L20B1
Price: 37.70 USD
Availability: InStock

SKU: X9MPT125L20B1 Brand: ICP

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Overview

This is a genuine OEM 40VA control transformer (part number 1012722) for the ICP Tempstar Heil X9MPT125L20B1 gas furnace. The transformer steps line voltage down from 115V on the primary side to 24V on the secondary side, powering the low-voltage control circuit that drives the thermostat, gas valve, ignition control board, and relays. The 40VA rating supplies enough capacity to run these control loads together. When the transformer fails, the entire 24V control system loses power — the furnace will not respond to a thermostat call, the control board goes dark, and the unit is inoperative even with line voltage present.

Specifications

Spec	Value
Part Number	1012722
Type	Step-Down Control Transformer
Brand	ICP (Tempstar / Heil)
VA Rating	40 VA
Primary Voltage	115 V
Secondary Voltage	24 V
Fit	OEM Replacement

Compatibility

Engineered for the ICP Tempstar Heil X9MPT125L20B1 two-stage gas furnace. This 40VA 115/24V transformer is also used across many ICP-family (Tempstar, Heil, Comfortmaker, Arcoaire) gas furnace platforms. Confirm your existing transformer is rated 40VA with a 115V primary and 24V secondary before ordering.

Installation Guide

Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter.
Access — Remove the furnace control/blower compartment service panel.
Document — Photograph all primary and secondary wire connections before disconnecting.
Remove — Label and disconnect the primary (115V) and secondary (24V) leads, then unbolt the failed transformer from its bracket.
Install — Mount the new transformer and reconnect the primary and secondary leads exactly per your photo.
Test — Restore power and confirm 24V across the secondary terminals and normal furnace startup.

Signs You Need a Replacement

No 24V at the control board or thermostat with line voltage present
Furnace completely unresponsive to a heat call
Repeatedly blown low-voltage fuse on the control board
Burnt smell or visible scorching on the transformer housing

Shipping & Returns

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

Shipping Information

Orders placed before 3PM CST ship same business day
Standard delivery: 2-5 business days
Express shipping available at checkout
Free shipping on orders over $75
Tracking number emailed upon shipment

Return Policy

30-day returns on unused parts in original packaging
Electrical parts (capacitors, contactors, control boards) are final sale once installed
Email info@nationalhvacparts.com to initiate a return
Refunds processed within 5-7 business days

ICP Step-Down Transformer for X9...

$37.70

Frequently Asked Questions

Does this Transformer fit my ICP X9MPT125L20B1 — 40VA 115V to 24V | Ships Today?

Yes. This is the factory-specified OEM transformer for the ICP X9MPT125L20B1 — 40VA 115V to 24V | Ships Today. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.

How do I replace the transformer on my ICP X9MPT125L20B1 — 40VA 115V to 24V | Ships Today?

Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Photo wiring connections. Step 3: Disconnect wires from old transformer. Step 4: Remove mounting hardware. Step 5: Install new transformer, reconnect wires matching voltage ratings. Step 6: Verify 24V output with multimeter.

My thermostat has no power. What failed?

Thermostat with no display = failed 24V transformer (or blown control board fuse). Check the 3A/5A fuse on the control board first ($1–$5 fix). If fuse is good but no 24V output from transformer, replace transformer.

Is this transformer compatible with Bryant or Payne too?

Many ICP parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.

Should I use OEM or aftermarket for my ICP transformer?

OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.

How fast does National HVAC Parts ship?

Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.

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