Shield® Water Heater & Boiler age
How to determine the date of production/manufacture or age of Shield® brand Water Heater & Boiler Systems.
Water heaters in general have an average estimated useful service life of 10-12 years, though water quality, routine upkeep/maintenance, and location of the water heater will all play critical roles in the longevity of these systems.
See also: Estimated Useful Service Life Expectancies
Parent Company: Lochinvar - A subsidiary of A.O. Smith (since 2011)
Subsidiaries or Related Brands: Aquas | Armor | Cadet | Copper-Fin | Copper-Fin II | Crest | EnergyRite | FTXL | Knight | Knight XL | Lochinvar | Noble | Power-fin | Shield | Squire | SYNC | and others.
The date of production/manufacture or age of Shield (Lochinvar) brand Water Heater & Boiler equipment can be determined from the serial number located on the rating data plate.
The multiple Serial Number styles shown were utilized with all Lochinvar Brand systems of Boilers, Water Heaters, Pool Heaters, etc. - but typically with specific model or series types. We suspect the various styles used are the result of outsourcing the manufacture of different series systems to other brand manufacturers.
Example serial number styles/formats found:
→Style 1: KJ-1000130
→Style 2: 1142N012345
→Style 3: J-930001
→Style 4: A07H00123456
→Style 5: J93-1030F
→Style 6: M78013
→Style 7: 5Y013 & 6S1064 & 11AA0365
→Style 8: 1234569708
→Style 9: 85041234
Legend: Year is RED; Month is GREEN; Week is BLUE
→Style 1: KJ-1000130
Year of manufacture can be determined by using the 1st position (letter) of the serial number
Month of manufacture can be determined by using the 2nd position (letter) of the serial number
NOTE: This style serial number is identical to Bradford White styling. Style was used with various models and system types from 1979 through 2011

→Style 2: 1142N012345
Year of manufacture can be determined by using the 1st & 2nd positions of the serial number
Week of manufacture can be determined by using the 3rd & 4th positions of the serial number
NOTE: This style was used with various models and system types from 2011 to present

→Style 3: J-930001
Year of manufacture can be determined by using the 1st & 2nd digits of the serial number
Month of manufacture can be determined by using the 1st letter of the serial number
NOTE: This style was used with various models and system types from 1978 to present


→Style 4: A07H00123456
Year of manufacture can be determined by using the 1st & 2nd digits of the serial number
Month of manufacture can be determined by using the 1st letter of the serial number
NOTE: This style was used with various models and system types from 1978 to present


→Style 5: J93-1030F
Year of manufacture can be determined by using the 1st & 2nd digits of the serial number
Month of manufacture can be determined by using the 1st letter of the serial number
NOTE: This style was used with 'Standard Hi-Power' & 'Oil Fired BRE Series' models and system types from 1974 to 1997

→Style 6: M78013
Year of manufacture can be determined by using the 1st & 2nd digits of the serial number
Month of manufacture can be determined by using the 1st letter of the serial number
NOTE: This style was used with HF, G-O, & PG series models and system types from 1965 thru 1986

→Style 7: 5Y013 & 6S1064 & 11AA0365
Year of manufacture can be determined by using the 2nd or 2nd & 3rd positions (letter/s) of the serial number
Month of manufacture can be determined by using the 1st or 1st & 2nd positions (number) of the serial number
NOTE: This style was used with Copper-Fin series water heaters & boilers from 1968 thru 1981


→Style 8: 1234569708
Year of manufacture can be determined by using the 7th & 8th digits of the serial number
Month of manufacture can be determined by using the 9th & 10th digits of the serial number
NOTE: This style was used with Electric Boosters (SB) series from 1978 thru 2010 and always is a 10-digit serial number.

→Style 9: 85041234
Year of manufacture can be determined by using the 1st & 2nd digits of the serial number
Month of manufacture can be determined by using the 3rd & 4th digits of the serial number
NOTE: This style was used with HF, G-O, & PG series models and system types from 1984 thru present. It is always an 8-digit serial number.

Lochinvar® History¹
- 1919 - Founder, Walter Vallett, Sr., enters the water heater business and begins his career with Everhot Water Heating Company
- 1939 - Walter Vallett Company is founded, marketing residential, commercial and industrial water heaters
- 1954 - Walter Vallett Company acquires Michigan Tank and Furnace and purchases the Lochinvar brand
- 1957 - Walter Vallett Company changes its name to Lochinvar Water Heater Corporation, headquartered in Detroit, MI
- 1970 - Lochinvar acquires Wagoner Water Heater Company and relocates to Nashville, TN
- 2001 - Lochinvar moves into a new state-of-the-art 360,000 sq. ft. world headquarters and manufacturing facility, located in Lebanon, TN
- 2011 - Lochinvar is acquired by A.O. Smith Corporation
1 - History excerpts from https://www.lochinvar.com/about/