HVAC date-code guide

Miller HVAC serial number lookup

Miller specializes in manufactured-home HVAC. A common serial style places the two-digit year and month in characters four through seven.

Parent: Nortek Global HVAC
Common code: A widely used style places a two-digit year in positions 4–5 and a two-digit month in positions 6–7.
Reviewed: August 8, 2026

Instant equipment lookup

Decode the manufacturing date

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Equipment type

Manufacturer or brand

Using A widely used style places a two-digit year in positions 4–5 and a two-digit month in positions 6–7.

Serial number

Type exactly what is printed. Spaces and dashes are ignored.

Optional: add model number for capacity cluesAdd model

Model number

Model decoding is labeled as a clue unless the exact format is documented.

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EQUIPMENT DATA

MODEL24ABC636A003

SERIAL5019X30312

WeekYear

See exactly how the code was read

SerialAtlas highlights the date characters, names the matching rule, and shows alternative interpretations when the code is ambiguous.

Current age calculated automatically
Confidence and rule source shown
Optional model-capacity clue

How to read a Miller HVAC serial number

A widely used style places a two-digit year in positions 4–5 and a two-digit month in positions 6–7. SerialAtlas removes spacing and punctuation, then applies only the documented rule families mapped to Miller HVAC. The lookup remains in the browser.

Try this documented-style exampleGBB030708229Load example

Equipment covered

air conditioners
heat pumps
furnaces
air handlers
manufactured-home systems

Commercial, imported, very old, specialty, and private-label equipment can use a different code. Confirm the full rating plate before accepting a result.

Where to find the rating plate

Outdoor condenser or heat-pump cabinet, usually near the service valves
Inside the furnace or air-handler access panel
On the packaged-unit rating plate
Near the electrical disconnect or wiring diagram

Why more than one date can appear

Two-digit years and repeating letter cycles can point to more than one era. SerialAtlas ranks the plausible dates but keeps materially different alternatives visible. Label design, refrigerant, installation records, and product literature can resolve the era.

Source and verification

Inspector Handbook open reference data (CC BY 4.0). Independently implemented and reviewed August 8, 2026.

Open reference source

What this result does not prove

A manufacture date is not an installation date, warranty decision, recall match, condition assessment, or replacement recommendation. Confirm high-stakes decisions with the manufacturer or a qualified professional.