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Tempstar 40VA Transformer for T8MPN150J20B2 — 115V to 24V | Ships Today
Tempstar

Tempstar 40VA Transformer for T8MPN150J20B2 — 115V to 24V | Ships Today

SKU: 1172810-GEN Brand: Tempstar

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

Overview

This OEM control transformer (part #1172810) converts the incoming 115V line voltage to the 24V control voltage that powers your Tempstar T8MPN150J20B2 furnace's thermostat circuit, gas valve, igniter sequence, and control board. Rated at 40VA, it provides the low-voltage power the entire control system relies on to operate. A failed transformer kills the furnace on the low-voltage side: the thermostat may go dark, the unit ignores calls for heat, and the control board's low-voltage fuse may blow repeatedly. A transformer that buzzes, overheats, or smells scorched has failed internally and should be replaced before it damages other components.

Specifications

Spec Value
Part Number 1172810
Type Control Transformer
Brand Tempstar
Primary Voltage 115V
Secondary Voltage 24V
Rating 40VA
Fitment OEM

Compatibility

Engineered as a direct-fit replacement for the Tempstar T8MPN150J20B2 gas furnace. Also widely used across ICP-family furnaces (Tempstar, Heil, Comfortmaker, and Arcoaire) sharing the same 115V-to-24V 40VA control circuit. Confirm the VA and voltage ratings of your existing transformer before installing.

Installation Guide

  1. Safety First — Disconnect power at the furnace switch and breaker, then verify zero voltage with a multimeter.
  2. Access — Remove the furnace control/blower access panel.
  3. Document — Photograph all primary (line) and secondary (24V) wire connections before disconnecting.
  4. Remove — Disconnect the wire leads, remove the mounting screws, and lift out the old transformer.
  5. Install — Mount the new transformer and reconnect the 115V primary and 24V secondary leads exactly per your photo.
  6. Test — Restore power, confirm 24V at the secondary terminals, and verify the furnace responds to a call for heat.

Signs You Need a Replacement

  • Furnace is completely unresponsive to the thermostat
  • Repeatedly blown low-voltage fuse on the control board
  • No measurable 24V output at the secondary terminals
  • Transformer is hot, buzzing, or smells burnt

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

Frequently Asked Questions

Does this Transformer fit my Tempstar T8MPN150J20B2 — 115V to 24V | Ships Today?
Yes. This is the factory-specified OEM transformer for the Tempstar T8MPN150J20B2 — 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 Tempstar T8MPN150J20B2 — 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 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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Mike Rivera
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