A.O. Smith

5 field manuals · 10 error codes · 2 guides

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Water Heater Model & serial

A.O. Smith water heaters

Manual · Water Heater

A.O. Smith Voltex / ProLine XE Voltex hybrid heat pump water heater: quick sheet

A.O. Smith Voltex hybrid heat pump water heaters: older HPTU-50N/66N/80N, current ProLine XE Voltex HPTU-50CTA, FPTU-80, and Voltex AL Smart HPTS (anti-leak). Model letters vary by channel; confirm on the rating plate.

6 components2 common failuresA.O. Smith, State
Manual · Water Heater

Electric tank water heater: field service manual

Residential 240 V dual-element tank heaters (roughly 30-80 gal) with surface-mount upper thermostat/ECO and lower thermostat

6 components4 common failuresA.O. Smith, State, Rheem, Ruud, Richmond, Bradford White, Whirlpool
Manual · Water Heater

Gas tank water heater (atmospheric and power-vent): diagnostic and electrical-side manual

Residential standing-pilot FVIR tanks with thermopile electronic gas controls, and 120 V power-vent tanks; diagnosis and electrical/water-side only

4 components3 common failuresA.O. Smith, State, Rheem, Ruud, Bradford White, Whirlpool
Manual · Water Heater

Gas tankless water heater: field service manual (water side and diagnostics)

Residential non-condensing and condensing gas tankless units with digital controllers

5 components3 common failuresRinnai, Navien, Noritz, Rheem, A.O. Smith, Bradford White
Manual · Water Heater

Heat pump (hybrid) water heater: field service manual

Residential integrated heat pump water heaters with backup resistance elements

4 components3 common failuresRheem, A.O. Smith, Bradford White, State

Error codes

5 ECO high-limit tripped16 / 17 Power anode fault1 flash (every 3 s) Normal: pilot lit, control OK2 flashes Low thermopile voltage4 flashes Over-temperature shutdown (ECO)5 flashes Sensor failure7 flashes Gas control failure8 flashes Knob OFF but thermopile still pr…No light Control not powered: pilot outSteady (solid) light Control turned OFF, thermopile c…
Guide · Water Heater

Tankless: error code, no ignition at low flow, or temperature swings

Many tankless complaints are water-side: flow below the activation threshold, a clogged inlet screen, low-flow aerators, or scale in the heat exchanger. Gas supply, venting and combustion codes are blocked: diagnose and refer. Read the code first, then work the water side.

6 steps ~90 minmoderate

Identify a A.O. Smith

Product lines by era

Line / seriesApplianceYearsNotes
Signature (retail)Water Heaterapprox. 2010s– (Lowe's exclusive as of 2017)Model pattern: Signature 100/300/500/900. Retail line; tier numbers track warranty (approx. 6/9/12 yr; 900 = heat pump). Warranty figures conflict between sources.
ProLine (formerly ProMax)Water HeatercurrentProfessional (distributor/contractor) line, upgraded parts; XE = high efficiency.
VertexWater HeatercurrentHigh-efficiency gas tank line (ENERGY STAR).
VoltexWater HeatercurrentHybrid heat-pump electric; modes: heat pump, hybrid, electric, vacation.
Cyclone XHEWater Heater1996–Commercial condensing gas water heater.
American Water Heater (brand)Water Heater2006– (acquired)Bought 2006; supplied Whirlpool-branded heaters to Lowe's.

Official A.O. Smith manuals & support

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