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Lennox

OEM Lennox Research Products 4010 24V Replacement Transformer — 22N03

SKU: LNX-22N03 Brand: Lennox
$29.95 $39.95

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Texas CMBL #19328542014
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Govt POs Accepted

The Lennox 22N03 is a genuine OEM Research Products 4010 24-volt replacement transformer designed to power the low-voltage control circuits in Lennox heating and cooling systems, including thermostats, relays, and control boards. This transformer steps down line voltage to the 24VAC required by the system's control components, ensuring stable and reliable operation throughout all modes of system function. Symptoms of a failed transformer include a completely unresponsive thermostat, loss of control signal, blown fuses on the control board, or the system failing to energize — all indicators that this OEM Lennox transformer should be replaced.

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 Lennox OEM Lennox Research Products 4010 24V Replacement Transformer — 22N03?
Yes. This is the factory-specified OEM transformer for the Lennox OEM Lennox Research Products 4010 24V Replacement Transformer — 22N03. 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 Lennox OEM Lennox Research Products 4010 24V Replacement Transformer — 22N03?
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 Lennox 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 Lennox 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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