What are the specs for this Transformer?

The correct replacement for Tempstar model T8MPN100J20A1 — OEM 1012722 | 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 Tempstar equipment which lists the model number T8MPN100J20A1 — OEM 1012722 | Ships Today.

Is this transformer compatible with Bryant or Payne systems too?

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

Tempstar

Tempstar 40VA Transformer 115V to 24V for T8MPN100J20A1 — OEM 1012722 | Ships Today

Name: Tempstar 40VA Transformer 115V to 24V for T8MPN100J20A1 — OEM 1012722 | Ships Today
Brand: Tempstar
SKU: 1012722-GEN
Price: 26.95 USD
Availability: InStock

SKU: 1012722-GEN Brand: Tempstar

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Overview

This OEM control transformer (part number 1012722, TRANS 115>24 40VA) steps the 115V line voltage in the Tempstar T8MPN100J20A1 down to the 24V needed by the thermostat, gas valve, and control board. Rated at 40VA, it supplies the low-voltage control circuit that runs the entire heating sequence. A failed transformer means a completely dead control board — no thermostat response, no ignition, no blower. It is a common failure after a control-circuit short or a power surge.

Specifications

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

Compatibility

Direct-fit replacement for the Tempstar T8MPN100J20A1 and other ICP/Heil/Comfortmaker furnaces using the 1012722 40VA 115-to-24V transformer. Verify primary voltage and VA rating against your existing unit before installing.

Installation Guide

Safety First — Disconnect power at the switch and breaker and verify zero voltage with a multimeter.
Access — Remove the control-compartment service panel.
Document — Photograph all primary (line) and secondary (24V) wire connections.
Remove — Label and disconnect the leads, then unbolt the old transformer from the cabinet.
Install — Mount the new transformer, reconnect primary and secondary leads per your photo, and confirm the ground.
Test — Restore power and measure 24V across the secondary terminals to confirm output.

Signs You Need a Replacement

No 24V at the control board or thermostat.
Furnace completely unresponsive to the thermostat.
Transformer is hot, swollen, or smells burnt.
Repeated blown control-circuit fuse after a short.

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

Tempstar 40VA Transformer 115V t...

$26.95

Frequently Asked Questions

Does this Transformer fit my Tempstar T8MPN100J20A1 — OEM 1012722 | Ships Today?

Yes. This is the factory-specified OEM transformer for the Tempstar T8MPN100J20A1 — OEM 1012722 | 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 Tempstar T8MPN100J20A1 — OEM 1012722 | 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 Tempstar 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 Tempstar 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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