Water Heater Heating Element by Wattage and Voltage: Which Screw-In or Flange Element Matches Your Rating Plate
Match the rating plate: same voltage, no greater wattage (A.O. Smith). Camco screw-in elements: 1 in NPS thread, 1-1/2 in hex; 4500 W at 240 V is ProLine standard.
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Short answer
A replacement water heater heating element is chosen from the rating plate, not from the old element. A.O. Smith’s residential electric manual (document 185762) states that replacement elements must be the same voltage and no greater wattage than the rating plate lists, and Rheem’s hybrid water heater use and care manual says to specify voltage and wattage as marked on the rating plate. A.O. Smith’s ProLine tanks run 4500 W elements at 240 V: its March 2025 spec sheet prints 4500 W as the standard wattage on every model, with a 6000 W maximum. Camco’s 2021 plumbing catalog maps plate values to stock numbers, for example 02583 (low watt density) and 02923 (ultra-low watt density) at 4500 W 240 V, and prints the screw-in thread as 1 inch NPS with a 1-1/2 inch hex. Fill the tank and run a hot faucet until water flows before restoring power: A.O. Smith will not warrant a dry-fired element.
The picks
Plate reads 240 V 4500 W and the water is hard
Camco 02583 low watt density screw-in foldback element, 4500 W 240 V
Camco 2021 catalog: 4500 W at 240 V (3500 W at 208 V), low watt density screw-in foldback, 1 in NPS, 13 in minimum tank diameter, gasket 06822 included, UL listed for USA and Canada
Rheem or Ruud tank, plate reads 240 V 4500 W, wants the Rheem-branded part
Rheem SP10869MM screw-in element, 240 V 4500 W, resistored stainless steel
Listing title: screw-in 240 V 4500 W, premium resistored stainless steel. Rheem's hybrid manual prints AP10869ML-7 as Element 4.5KW; the SP10869 retail number was not found on a Rheem page this session
Rheem-branded 240 V 4500 W at the standard density tier
Rheem SP10552MH resistored high watt density screw-in element, 240 V 4500 W
Listing title: resistored HWD screw-in 240 V 4500 W. No Rheem document naming this part was opened this session
Plate reads 240 V 3500 W
Camco 02283 high watt density screw-in element, 3500 W 240 V
Camco 2021 catalog: 3500 W at 240 V (2500 W at 208 V), high watt density screw-in, 1 in NPS, 14 in minimum tank diameter, gasket 06822 included
Owns a 1/2 in drive ratchet and wants the maker-documented tool
Camco 09953 Professional Element Socket
Camco 2021 catalog: chrome-plated element socket, fits a standard 1/2 in socket drive, for screw-in elements with the 1-1/2 in hex
Wants a cheaper 1-1/2 in socket
Timsec 1-1/2 in water heater element socket, 1/2 in drive
1-1/2 in socket with 1/2 in drive per the listing title; the 1-1/2 in hex figure comes from Camco's catalog and A.O. Smith's guide, not from Timsec
“Fits most water heaters” in a listing title is true of the thread and silent on wattage: the plate decides, and a bigger number is the swap both makers forbid.
Which element matches the rating plate?
Read the plate near the lower access panel (A.O. Smith: “equipped for one type voltage only”), pick the row, then a column by density.
| Plate reads | High watt density (Camco “standard”) | Low watt density (“better”) | Ultra-low watt density (“premium”) |
|---|---|---|---|
| 1500 W, 120 V | 02143 | 02463 | 02853 |
| 2000 W, 120 V | 02203 | Not listed | Not listed |
| 2500 W, 240 V | 02243 | 02493 | 02903 |
| 3500 W, 240 V | 02283 | 02523 | 02913 |
| 3800 W, 240 V | 02293 | Not listed | Not listed |
| 4500 W, 240 V | 02343 (02643 foldback) | 02583 | 02923 (02953 ripple) |
| 5500 W, 240 V | 02363 foldback | Not listed | 02933 (02963 ripple) |
| 6000 W, 240 V | Not listed | 02613 | 02972, special order |
All are Camco screw-in elements, 1 in NPS, shipped with gasket 06822, per Camco’s 2021 catalog, which also prints a minimum tank diameter: 13 in for the 02583 , 15 in for the wider folded-back 02923.
Tank size does not fix wattage: A.O. Smith’s ProLine sheet lists 4500 W standard on every model, 3500 to 6000 W allowed on the ENT-40, and “W” suffix models down to 1 kW.
Screw-in or flange?
| Style | How it mounts | Camco gasket | 4500 W 240 V examples |
|---|---|---|---|
| Screw-in | 1 in NPS thread, 1-1/2 in hex | 06822 | 02343, 02583, 02923 |
| Flat flange | Bolted plate, no thread | 06842 | 03943 (HWD), 04103 (LWD) |
| Universal flange | Bolted plate, 4-hole | 06882 | 04603 (HWD), 04703 (LWD), 04943 (ultra-low) |
Camco’s conversion kit 07223, a 2-1/2 in four-bolt “Adapt-a-Flange”, lets a screw-in element replace a flange element. Rheem Marathon tanks are the exception: Camco lists their elements as 1-1/2 in - 12 UNF, so a 1 in NPS part does not fit.
Low, high or ultra-low watt density?
State’s service handbook defines watt density as “the density of the wattage output of the element compared to the surface area of the element”: the most watts per square inch is high.
Camco ranks the tiers Standard, Better, Premium. High watt density is the cheapest and “the most susceptible” to surges, lime and dry-firing; low watt density elements are folded back to add surface. The ultra-low “Lime Life” tier is nickel chromium stainless steel with a 5-year limited warranty against 1 year for the others, sold as “best when water has high mineral content”; the water softener size calculator explains hardness.
What do the makers’ own documents say?
| Maker | The rule as printed | Element part numbers found |
|---|---|---|
| A.O. Smith | “Replacement elements must (1) be the same voltage and (2) no greater wattage than listed on the model rating plate” (manual 185762) | Parts list names “Element w/Gasket” and “Element Gasket” only; order by model, serial, “voltage and element wattage” |
| Rheem | “Specify voltage and wattage as marked on the rating plate”; “check the water heater’s rating label on the front of the unit for the acceptable element wattage” (AP23657) | AP10869ML-7 “Element 4.5KW”, AP18708JL “Element 2.25Kw” (hybrid manual) |
| Bradford White | Utility-model parts list; “for other wattages/voltages, consult residential Heating Element Replacement Parts List” (238-51592-00) | 415-42540-02 (1500 W 120 V copper), 415-42541-02 (Incoloy), gasket 223-34019-00 |
| Camco | Higher wattage “is not recommended. The water heater is designed for that element size” (2021 catalog) | The stock numbers in the tables above |
The Rheem SP10869MM and SP10552MH listings carry retail numbers no Rheem page confirmed this session. Camco gives the reason (heavier wire and a larger breaker); the wiring table in Rheem’s hybrid manual shows the scale: 2250 W takes a 15 A breaker on 14 AWG copper, 5500 W takes 30 A on 10 AWG, for that heat pump model.
Is the old element actually dead?
A.O. Smith’s use and care guide says a good element reads “between 5 and 25 Ohms” across its two screw terminals with the power off; outside that range, replace it. Check the reading with the element resistance test calculator first.
No hot water at all is usually not the element: A.O. Smith lists no power, a dry-fired upper element, a tripped energy cut-off and a broken upper thermostat first, so start with the no hot water guide. Less hot water than before points at the lower element, which A.O. Smith says “usually wears out before the upper element” and Camco credits with 90 percent or more of the heating.
How is the element changed?
A.O. Smith’s sequence: power off and confirmed with a non-contact tester, hot faucet run until cool, hose on the drain valve, cold supply off, tank drained, wires off, old element out with an element wrench, new element checked against the data plate, dishwashing liquid on the new gasket. Camco prints the hex as 1-1/2 in and sells the 09953 Professional Element Socket for a 1/2 in drive; A.O. Smith warns ordinary sockets “are often beveled and may slip”.
Refilling is the step that kills elements. A.O. Smith: run a hot faucet full for at least three minutes before restoring power; “a Dry Fired upper heating element is an installation error and is not covered under warranty”. A crusted old element means the sediment flush guide is next.
Match the plate, then pick the tier
- The Camco 02583
- is the low watt density 4500 W 240 V part, not the premium tier, and on a 3500 W plate it is the wrong element: buy the 02283
- . Rheem owners get the SP10869MM
- , verified on the listing only. Add a 1-1/2 in element socket
- a slipping socket rounds the hex.
Frequently asked questions
Can I put a higher wattage element in my water heater?
The makers say no. A.O. Smith's manual 185762 states replacement elements must be the same voltage and no greater wattage than the rating plate lists. Camco's catalog calls a higher wattage not recommended because it might require heavier gauge wire and a larger capacity circuit breaker. The wiring table in Rheem's hybrid manual runs 2250 W on a 15 A breaker up to 5500 W on 30 A.
What size wrench removes a water heater element?
Camco's 2021 catalog prints a 1-1/2 inch hex on residential screw-in elements and sells a chrome-plated element socket (09953) for a standard 1/2 inch drive. A.O. Smith's use and care guide notes that some regular 1-1/2 inch sockets may work, but regular sockets are often beveled and may slip, and recommends an inexpensive element wrench from a plumbing supplier.
What is the difference between low and high watt density?
State's service handbook defines watt density as the wattage output compared to the surface area of the element, so a high watt density element has the most watts per square inch. Camco's catalog sells high watt density as its standard tier, low watt density as better (folded back to add surface) and ultra-low as premium, in nickel chromium stainless steel, for water with high mineral content.
Is a bad element why there is no hot water at all?
Not usually. A.O. Smith's use and care guide lists the most likely causes of no hot water as no electric power, a dry-fired upper element on a new install, a tripped energy cut-off and a broken upper thermostat. A failed lower element gives some hot water but less than before. A good element reads between 5 and 25 ohms across its two terminals.
Do I have to drain the tank to change an element?
Yes, in A.O. Smith's procedure: power off and checked with a non-contact tester, hot faucet run until cool, garden hose on the drain valve, cold supply off, then the old element comes out with an element wrench. Refill with a hot faucet open and let it run full for at least three minutes before restoring power; a dry-fired element is not covered under warranty.
Fact sheet and how to cite this page
- Answer
- A replacement element is matched to the rating plate: residential electric manual 185762 requires the same voltage and no greater wattage than the plate lists, and Rheem’s manual AP23657 says to specify voltage and wattage as marked on the plate. The March 2025 ProLine spec sheet prints 4500 W at 240 V as standard on every model, and Camco’s 2021 catalog maps that value to stock numbers 02343, 02583 and 02923 by watt density.
- Applies to
- Plate: 1500 W or 2000 W at 120 V
- Plate: 2500 W, 3500 W, 3800 W, 4500 W or 5500 W at 240 V
- Style: screw-in (1 in NPS) or flat or universal flange
- Density: high, low or ultra-low watt density
- Compatibility basis
- A.O. Smith instruction manual 185762 and Use and Care Guide 100309797; A.O. Smith ProLine spec sheet AOSRE50608; Rheem hybrid use and care manual AP23657; State Residential Electric Service Handbook STC082; Camco Plumbing and Hardware catalog 2021; Bradford White electric replacement parts list 238-51592-00
- Assumptions
- Camco stock numbers, thread size, hex size, density tiers and minimum tank diameters are copied from Camco’s 2021 Plumbing and Hardware catalog, the most recent Camco document found at a citable URL this session.
- Rheem’s retail SP10869 and SP10552 element numbers appear only in listing titles. The Rheem document opened this session is the hybrid heat pump manual, which prints the related AP10869ML-7 as Element 4.5KW; it is not proof that the two numbers are the same part.
- A.O. Smith’s own element part numbers, and Reliance and Whirlpool element part numbers, were not found on any maker page this session, so none appear here. Bradford White’s full residential heating element parts list was not located; only its utility-model list is cited.
- Method
- Rules, part numbers, thread and hex sizes, wattage tables and installation steps copied from each manufacturer’s own manual, spec sheet, handbook or catalog. OwnerSpec removed no element and measured nothing.
- Primary source
- A.O. Smith, Instruction Manual, Residential Electric Water Heaters Models 6-120, document 185762 (PDF) (manufacturer or vendor document)
- Facts verified
- Last updated
- Canonical URL
- https://ownerspec.com/plumbing/parts/water-heater-heating-element-by-wattage-and-voltage/
- Cite as
- OwnerSpec, "Water Heater Heating Element by Wattage and Voltage: Which Screw-In or Flange Element Matches Your Rating Plate", https://ownerspec.com/plumbing/parts/water-heater-heating-element-by-wattage-and-voltage/, facts verified 2 October 2026.
Every figure above also appears, with its source, in the article. All sources ยท How OwnerSpec verifies numbers
Sources
- A.O. Smith, Instruction Manual, Residential Electric Water Heaters Models 6-120, document 185762 (PDF) (manufacturer or vendor document)
- A.O. Smith, Installation Instructions and Use and Care Guide, Residential Electric Water Heater, 100309797 Rev B, September 2020 (PDF) (manufacturer or vendor document)
- A.O. Smith, ProLine Commercial-Grade Residential Electric Water Heaters specification sheet AOSRE50608, March 2025 (PDF) (manufacturer or vendor document)
- Rheem, Electric Residential Hybrid Water Heater Use and Care Manual AP23657 Rev 04 (PDF) (manufacturer or vendor document)
- State Water Heaters, Residential Electric Water Heater Service Handbook STC082, document 320990-000 (PDF) (manufacturer or vendor document)
- Camco Manufacturing, Plumbing and Hardware catalog 2021 (72001), water heater elements pages 4 to 8 and 15 (PDF) (manufacturer or vendor document)
- Bradford White, Electric Replacement Parts List, Residential RE(1,2)U and Commercial LE(1,2)U Utility Models, 238-51592-00, October 2024 (PDF) (manufacturer or vendor document)