Honeywell Serial Number Lookup & Date Codes

T3 wired and T3R wireless thermostats described in the 2021 Resideo policy.

The code gives production year/week, not exact production day. This rule is not assigned to every Honeywell product or every thermostat. The selected T3/T3R family uses the 2000s century; an older unrelated four-digit code needs a separate source.

Confirm a T3 or T3R thermostat and copy the separate four-digit date code, not its MAC ID or model.

Honeywell/Cadet T4700, CT1950 and CT1957 baseboard and fan-heater thermostat date labels.

The manufacturer documents this product era and marks 00–06 year codes in a recall. A matching date is not a complete recall, safety or eligibility determination; compare the exact model with the linked manufacturer notice.

Confirm a T4700, CT1950 or CT1957 electric baseboard/fan thermostat and use the date code at the far right of its label.

Honeywell/Resideo security product or board date stamps using the manufacturer’s historical table.

Letters are not sequential across every year and some repeat. For example F159 fits 2003 and 2022 until device context narrows it. Migration to YYWW began in June 2022; this does not establish an exact universal changeover day. This is a date stamp, not an alarm enrollment/zone serial.

Confirm a Honeywell/Ademco/Resideo security product date stamp using a year letter plus three-digit day-of-year.

Resideo security product and box date labels in the new format.

Migration began June 2022. The source does not give one mandatory changeover day for every product; early-2022-looking codes require manufacturer confirmation. The four-digit date code is separate from the unique security enrollment serial.

Confirm a Resideo/Honeywell security product or box label using the new YYWW format introduced in June 2022.

Honeywell Sensing Solutions industrial sensors/switches, including LSA1A marked LSA1A 1925 or LSA1A 19 25.

The manufacturer identifies 1925 as week 25 of 2019 in its example. A two-digit year alone does not establish the century for every historical component; select a known decade to resolve it. LSA1A is a separate part/model number and is not derived from 1925.

Confirm a Honeywell Sensing Solutions industrial component and enter only its separate four-digit date code after the part number.

Honeywell/Datamax-O’Neil Apex 2, 3, 4 and 2i, 3i, 4i portable printers.

First two digits are year and next two month. The source example 1808110011 is August 2018. The remaining six digits are not decoded into an invented model, factory or production count. A known decade resolves the century.

Confirm an Apex 2/3/4 or Apex 2i/3i/4i printer with its complete ten-digit serial.

Midas IR COS, C4F6, NF3 and CH3 modules identified by Honeywell article 000092030.

The module serial identifies a module model, not an entire installed gas monitoring system. Honeywell documents updated parameters at and after week 31 of 2024; this date decoder does not certify firmware, calibration, service life or safety.

Confirm a Midas IR module using the listed A93/A94/B21/B22 product-code system.

Honeywell XNX detector full serial on box/POD labels. Exact model mapping covers only the manufacturer-listed North American/UL configurations.

First six digits are a configuration reference, followed by week, year and four-digit production number. An unlisted six-digit code remains unresolved; model mappings are never generalized from similar prefixes. Certification codes do not identify the manufacturing country.

Confirm an XNX detector POD or original box label containing the full 14-digit number.

Honeywell XNX enclosure labels that omit the six-digit configuration prefix.

Week/year/production number remain readable, but an eight-digit enclosure serial does not contain the configuration/model prefix. Read the complete box or POD serial to attempt the documented exact model match.

Confirm an XNX detector enclosure: its label shows only the last eight digits of the full box/POD number.

City Technology gas sensor labels BBCCCCCCCCDDD documented by Honeywell.

Final MMY date repeats every decade. For example 072 means July in a year ending in 2; the code itself does not establish a decade. Neither the revision nor sensor serial is an instrument model. This is not a calibration, expiry or serviceability determination.

Confirm a City Technology gas sensor label with two revision characters, eight serial characters and a final three-digit date code.

Sensoric gas sensor labels AABBCCCCCCCCDDD with the documented Bonn/Portsmouth site identifier.

Site 00 is the historical Bonn site and site 01 Portsmouth. Honeywell warns that Bonn sensors should have exceeded warranty periods; decoding is not a statement that an old sensor is safe or serviceable. Final MMY repeats every decade, so retain all compatible years until a known decade is supplied.

Confirm a Sensoric gas sensor label beginning with site00/01, followed by revision, eight serial characters and a final MMY date code.

Separate three-digit gas sensor date field; not Fox MOX hourglass use-by date.

The same three-digit date field repeats every decade. Honeywell’s 072 example means July 2022 with its source context; the code alone also fits other decades. On Fox MOX sensors, the date beside the hourglass is a use-by date and must not be treated as the manufacture date.

Confirm the separate three-digit MMY manufacture date code on a City Technology or Sensoric gas sensor.