GSW Water Heater Age Lookup

GSW is a longtime Canadian manufacturer of gas, electric, and power-vent water heaters. Type your serial number in to find the build date and age of your GSW unit. No account, no charge.

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GSW Water Heater

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Finding Your GSW Serial Number

Check these four spots on your GSW water heater

GSW water heater serial number locations

Common Locations

1
Side panel
near the bottom
2
Front panel
access / service door
3
Behind covers
removable access panels
4
Jacket label
upper side or top of tank

What to Look For

  • White or metallic manufacturer sticker
  • Labeled "Serial No." or "S/N"
  • Typically 8–12 characters long
  • Usually near the model number

Can't find it? Try removing access panels or checking behind the temperature dial.

GSW Serial Number Examples

GSW
0331263882U1117F70063S1001F701883
Style 1: 1st–2nd digits = year, 3rd–4th digits = week · Style 2: ignore letter prefix, 1st–2nd digits = year, 3rd–4th digits = month (pre-2008) or week (2008+)

Don't worry if yours looks different - GSW has multiple formats and our system can decode most variations.

About GSW Water Heaters

GSW water heaters carry a manufacturing heritage that stretches back to the 1927 founding of General Steel Wares in Ontario, Canada, through a merger of several prominent Canadian metalware companies including McClary Manufacturing and the Thomas Davidson Manufacturing Company. The GSW name became closely associated with quality Canadian-made water heaters following the 1961-62 reverse takeover of General Steel Wares by Beatty Brothers Limited, a company with roots going back to 1873 in Fergus, Ontario. Beatty Brothers had built its reputation on agricultural machinery before expanding into domestic appliances, and after the merger the combined company focused increasingly on residential water heating as one of its core product lines. By the time Beatty Brothers formally merged into GSW Limited in 1969, the Fergus facility had become a dedicated water heater production hub serving the Canadian market.

GSW expanded significantly in 2002 when it acquired American Water Heater Company, briefly becoming the third largest water heater manufacturer in North America and gaining access to Whirlpool and U.S. Craftmaster production contracts. This growth attracted A.O. Smith Corporation, one of the world's leading water heater producers, which completed its purchase of GSW Limited and its subsidiaries in 2006. A.O. Smith consolidated manufacturing operations over the following years, ultimately announcing the closure of the historic Fergus production facility in 2013 with the loss of approximately 350 manufacturing jobs, though the site retained its role as the Canadian headquarters for A.O. Smith's regional sales, marketing, finance, and distribution operations. GSW branded water heaters continue to be manufactured under A.O. Smith's production network and distributed through Canadian Tire, Home Hardware, Rona, Lowe's, and other national and regional Canadian retailers.

GSW water heaters use a year-and-week or year-and-month serial number format depending on the production era. Units manufactured before 2008 encode the manufacture year in the first two digits and the month of production in the next two digits. Units manufactured in 2008 and later use week-of-year encoding in those same positions. Some GSW serials begin with a single letter prefix followed by the four-digit date code and a separate alphanumeric batch code. Knowing the production year allows owners to assess remaining service life and plan for replacement before issues arise, especially important for older GSW units approaching or exceeding the 10-12 year average water heater lifespan.

Where to find the serial

GSW water heaters are Canadian-built (Fergus, Ontario) and sold heavily in Canada and parts of the northern US. The rating plate is on the upper third of the tank, with bilingual English/French labeling. The serial follows the standard YYWW format used across the A.O. Smith family.

What the serial actually looks like

1925A554433
Year 19 (2019), week 25, mid June 2019. GSW serials follow the YYWW convention inherited from their Mor-Flo-era heritage and now standardized across A.O. Smith's North American plants.

Why the age is worth knowing

GSW residential tanks typically carry 6 to 12-year tank warranties. The build quality is comparable to A.O. Smith mainstream units and service life in Canadian soft-water regions often exceeds 12-15 years. After year 8 in hard water areas, anode rod inspection is worthwhile.

Quick answers for this brand

Is GSW the same as John Wood?

Both brands are produced by the same Canadian A.O. Smith subsidiary (formerly GSW Limited), with manufacturing centered on Fergus, Ontario. John Wood is the better-known consumer brand while GSW serves wholesale and house-brand channels. The tanks are essentially the same with different badges.

Are GSW parts hard to find in the US?

GSW parts are most readily available in Canada through Canadian plumbing wholesalers. In the US, A.O. Smith plumbing distributors can typically cross-reference GSW part numbers to equivalent A.O. Smith family parts. Generic universal parts (anode, T&P, elements) fit any standard tank including GSW.

How long is the GSW warranty?

GSW warranties range from 6 to 12 years on the tank depending on the model line, with parts warranties typically running 1-6 years separately. Warranty registration is required for some extended terms - check your owner's manual or the GSW website for the specific terms on your model.

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