Nordyne / Intertherm Serial Number Lookup
Nordyne built Intertherm and Miller furnaces, common in manufactured homes, plus HVAC sold under names like Maytag and Frigidaire. On these serials, characters 4–5 are the year and 6–7 the month. Enter yours below.
Part of the hvac age lookup
Serial number age lookup
Where to find the serial number
Nordyne-built furnaces in manufactured homes are usually installed in a hallway closet. The rating label is inside the lower front door or on the inner side panel. Outdoor air conditioners and heat pumps have the plate on the cabinet side. Look for the line marked Serial No., a mix of letters and digits typically 12 or 13 characters long.
Model numbers for these furnaces often start with letters such as M1, M3, M7 (gas) or E1, E2, E3, E7 (electric), followed by capacity codes.
How the Nordyne date code works
| Characters | Meaning | Example (LMB0807K12345) |
|---|---|---|
| 1–3 | Product/plant code | LMB |
| 4–5 | Year | 08 = 2008 |
| 6–7 | Month | 07 = July |
| rest | Sequence | not part of the date |
- Year
- Month
- Not part of the date
Worked examples
| Serial | Built |
|---|---|
| LMB0807K12345 | July 2008 |
| ABC1503X54321 | March 2015 |
| M3K1911A12345 | November 2019 |
| E2A9606B12345 | June 1996 |
Example serials are made up to show the format; they don't belong to real units.
The same layout applies whichever badge is on the front (Intertherm, Miller, Nordyne, Maytag, Frigidaire, Westinghouse and others), so pick the closest brand in the menu or leave Nordyne selected.
The manufactured-housing furnace maker
Nordyne, based in the St. Louis area and later renamed Nortek Global HVAC, was for decades one of the main suppliers of heating and cooling for manufactured and mobile homes. Its Intertherm and Miller furnaces are designed for the tight closets and floor-duct systems of those homes, and many are still running.
Nordyne also made site-built home equipment under licensed brand names. That’s why you might find a “Maytag” or “Frigidaire” furnace even though neither appliance company built HVAC equipment.
Gas vs electric
- Gas furnaces (M-series): age the same way as other gas furnaces. Watch the heat exchanger, the venting and the burners.
- Electric furnaces (E-series): no flame and no heat exchanger, so they can run a long time. Heating elements, sequencers and relays fail over the years and are replaceable. A unit with frequent element failures and corroded wiring is near the end.
How long Nordyne equipment lasts
| Equipment | Typical life |
|---|---|
| Gas furnace | 15–20 years |
| Electric furnace | Often 20+ years, with element and relay replacements |
| Central air conditioner | 12–17 years |
| Heat pump | 10–15 years |
What to do with your result
Under 10 years: repairs are almost always worth doing. Parts for these brands are widely stocked by manufactured-housing supply stores.
10 to 20 years: keep it serviced. Have gas models’ heat exchanger and venting inspected every year.
Over 20 years (gas) or with repeated failures: replace. In a manufactured home, the replacement must be listed for manufactured-housing use, and often a direct replacement in the same footprint is simplest.
Frequently asked questions
How do I read an Intertherm or Nordyne serial number?
Skip the first three characters. The 4th and 5th are the year and the 6th and 7th are the month. LMB0807K12345 was built in July 2008.
What brands did Nordyne make?
Its own Intertherm and Miller brands, plus licensed names including Maytag, Frigidaire, Westinghouse, Broan, Gibson, Tappan and Philco heating and air conditioning. All share the same serial layout.
Is a Maytag furnace made by Maytag?
No. Maytag-branded furnaces and air conditioners were made under license by Nordyne (later Nortek Global HVAC), not by the appliance company.
How long does an Intertherm furnace last?
Typically 15 to 20 years for gas models. Electric furnaces in manufactured homes can last longer because there's no combustion, but their heating elements and sequencers wear out and need replacing.
My serial doesn't decode. Why?
Units made before about 1984 used a different system, and some Nordyne product lines put the date elsewhere. Check the label for a printed manufacture date, or call the manufacturer with the model and serial.
Sources and accuracy
The Nordyne: Intertherm / Miller / Maytag & Frigidaire HVAC decoder is built from these references and cross-checked between them. Facts are restated in our own words; any mistakes are ours.
- Building Intelligence Center: Nordyne HVAC age
- How To Look At A House: Miller furnace and AC age
- Energy Trust of Oregon: furnace age brand details (PDF)
Status: being verified against real data plates. Rules last reviewed 2026-10-18; page updated 2026-11-04. Not affiliated with Nordyne: Intertherm / Miller / Maytag & Frigidaire HVAC. Report a wrong result.
Part of the hvac age lookup
This page covers one brand. For all furnace, air conditioner and heat pump brands, go to the hvac age lookup.