A.O. Smith Water Heater Warranty Guide
Manufactured by A.O. Smith Corporation · Warranty info last verified: March 2026
A.O. Smith water heaters are covered by A.O. Smith Corporation. This guide covers 5 product lines: the Signature 100, Signature 300, Signature Premier, Gas Tankless, and Hybrid Heat Pump (NEXT Hybrid). Across those lines, tank or heat exchanger coverage climbs from 6 years on the Signature 100 to 15 years on the Gas Tankless, parts reach 10 years, and labor runs up to 1 year. The warranty stays with the original owner and does not transfer to later owners, and claims run through 800-527-1953. An extended warranty program, A.O. Smith Extended Warranty, is also available to lengthen coverage.
Quick Warranty Facts
Tank / H.E. Coverage
6–15 years
Parts Coverage
10 years max
Labor Coverage
1 year
Transferable
No
Extended Warranty
Available
Registration Required
Recommended
Warranty by Product Line
Coverage periods vary by model series. Check your model against the table below.
| Product Line | Tank / H.E. | Parts | Labor |
|---|---|---|---|
Signature 100 Entry-level residential line. | 6 yr | 6 yr | 1 yr |
Signature 300 Mid-tier residential line with added features. | 9 yr | 9 yr | 1 yr |
Signature Premier Premium residential line with advanced features. | 10 yr | 10 yr | 1 yr |
Gas Tankless 15-year heat exchanger warranty is among the longest for gas tankless units. | 15 yr | 5 yr | 1 yr |
Hybrid Heat Pump (NEXT Hybrid) Qualifies for federal tax credits. High-efficiency heat pump technology. | 10 yr | 10 yr | 1 yr |
How to Register Your A.O. Smith Water Heater
There is no strict registration deadline listed for A.O. Smith, yet filing it is smart insurance for the 5 lines shown here. Registration puts your purchase date and installer on record so a later claim through 800-527-1953 moves faster.
You will need:
- Serial number (from the rating label)
- Model number
- Installation date
- Installer's name and contact info
- Your name and address
Keep a copy with your A.O. Smith paperwork in case you later call 800-527-1953.
What's Covered
- Defects in materials and workmanship under normal residential use
- Signature 100: 6-year tank coverage, 6-year parts, and 1-year labor
- Signature 300: 9-year tank coverage, 9-year parts, and 1-year labor
- Signature Premier: 10-year tank coverage, 10-year parts, and 1-year labor
- Gas Tankless: 15-year heat exchanger coverage, 5-year parts, and 1-year labor
- Hybrid Heat Pump (NEXT Hybrid): 10-year tank and compressor coverage, 10-year parts, and 1-year labor
- Heat exchanger failure on the Gas Tankless and Hybrid Heat Pump (NEXT Hybrid)
What's NOT Covered
A.O. Smith lists 6 situations that fall outside coverage on its 5 lines:
- Improper installation not meeting local codes
- Lack of required maintenance (anode rod replacement, sediment flushing)
- Commercial use of residential-rated models
- Damage from sediment, scale, or water quality issues
- Units installed outside the US or Canada without authorization
- Labor after the first year
Extended Warranty: A.O. Smith Extended Warranty
Cost Range
$100–$200 (estimated)
Additional Years
+4 years
Includes Labor
No
Buy at Install
No
Optional extended warranty coverage adding years to tank and parts coverage. Contact A.O. Smith or your dealer for current availability and pricing.
How to File a A.O. Smith Warranty Claim
- 1
Register your product at aosmith.com/register
- 2
Locate serial and model numbers on the rating plate
- 3
Contact A.O. Smith support at 800-527-1953
- 4
A service technician will diagnose the issue
- 5
Warranty parts are shipped to the authorized service provider
- 6
Labor costs after year one are the homeowner's responsibility
A.O. Smith warranty line: 800-527-1953
Warranty Transferability: No
Warranty does not transfer to subsequent owners. Only the original purchaser is covered.
Bought a home that came with a A.O. Smith unit? Because A.O. Smith coverage stays with the first owner, the remaining warranty probably did not follow the sale to you, even if the calendar time has not expired. To confirm, decode the serial with our free tool for the manufacture date, then call the A.O. Smith line at 800-527-1953 (labor help is limited to 1 year from install).
Additional Notes
A.O. Smith Corporation is one of the world's largest water heater manufacturers and also produces heaters under the State, American, Reliance, Whirlpool, Craftmaster, and Lochinvar brand names. Warranty terms vary by brand and product line even within the A.O. Smith family. Always check the specific warranty certificate that came with your unit.
Related brands with similar warranty terms:
A.O. Smith Warranty FAQ
How many years does the A.O. Smith tank warranty last?
A.O. Smith tank or heat exchanger coverage ranges from 6 to 15 years, from the Signature 100 up to the Gas Tankless. Parts are covered for up to 10 years and labor for up to 1 year.
Can I transfer a A.O. Smith water heater warranty to a new owner?
No. A.O. Smith warranties are not transferable. Warranty does not transfer to subsequent owners. Only the original purchaser is covered.
How do I check whether my A.O. Smith water heater is still under warranty?
Decode your serial number with our free tool at WaterHeaterChecker.com to find the manufacture date, then compare it against the coverage for your line (Signature 100, Signature 300, Signature Premier, Gas Tankless, and Hybrid Heat Pump (NEXT Hybrid)). You can also call A.O. Smith at 800-527-1953 with your serial number.
What voids a A.O. Smith water heater warranty?
Common warranty voiding issues for A.O. Smith include: Improper installation not meeting local codes; Lack of required maintenance (anode rod replacement, sediment flushing); Commercial use of residential-rated models.
Does A.O. Smith sell an extended warranty for the Signature 100, Signature 300, Signature Premier, Gas Tankless, and Hybrid Heat Pump (NEXT Hybrid)?
Yes. A.O. Smith offers A.O. Smith Extended Warranty: Optional extended warranty coverage adding years to tank and parts coverage. Contact A.O. Smith or your dealer for current availability and pricing. It adds 4 years of coverage, does not include labor, and costs $100–$200 (estimated).
What should I do if my A.O. Smith water heater fails under warranty?
Register your product at aosmith.com/register. Then locate serial and model numbers on the rating plate. The A.O. Smith warranty line is 800-527-1953.
More for Your A.O. Smith Water Heater
Not sure which of A.O. Smith's 5 lines you have?
Coverage differs across A.O. Smith's lines, so decode your serial number to find the manufacture date and match it to the right 5-line warranty range above.
Decode Your A.O. Smith Serial NumberThe 5 coverage figures shown above were last verified in March 2026 and are provided as a helpful reference only. Warranty terms are set by A.O. Smith and may change at any time. Always refer to the warranty certificate that came with your water heater for the definitive terms of your coverage. WaterHeaterChecker.com is not affiliated with A.O. Smith or A.O. Smith Corporation.