The correct RV water-heater drain part depends on the heater itself. A Suburban tank heater typically drains through its sacrificial anode, while a Dometic/Atwood aluminum-tank heater uses a drain plug. Even among drain plugs, the thread arrangement can differ, so begin with the model label and the removed part rather than a visual guess.
Water-heater drain fitting identification diagram
Suburban tank-style water heater
The glass-lined steel tank uses a sacrificial anode rod at the drain opening. The rod is part of tank maintenance, not a separate plastic drain cap.
Atwood / Dometic aluminum-tank water heater
These tank heaters use a drain plug or cap and do not require an anode rod. Older Atwood and later WH-series caps may have different male/female thread arrangements.
Four checks that prevent the wrong order
| Check | What to verify | Why it matters |
|---|---|---|
| 1. Heater identification | Manufacturer, complete model and any product/serial identifier | A similar-sized heater is not necessarily built with the same drain part. |
| 2. Rod or cap | Whether the original is a long sacrificial anode, a threaded plastic plug or a female-thread cap | These have different jobs and cannot be substituted based on diameter alone. |
| 3. Connection style | Male versus female threads, nominal thread specification and original part number | Atwood 91857-style drain plugs and Dometic 92102 WH-series caps are not interchangeable just because both are drain parts. |
| 4. Service application | Tank heater versus tankless model, plus any manufacturer revision | A tankless drain/filter assembly may use a completely different component. |
Do not install an aftermarket anode in a Dometic/Atwood aluminum water-heater tank. Dometic specifically warns against this modification. Camco also markets various anode accessories; their presence in a catalog does not establish approval for your Dometic/Atwood heater.
Matching parts and product photos
These are individual NewRVParts listings, not a claim that every part fits every RV heater. Open the exact part to check its current specifications and availability.
Suburban magnesium anode rodPart 233514Standard Suburban anode option for compatible tank water heaters; also closes the drain opening.View product and availability →
Suburban aluminum anode rodPart 233516Suburban-listed aluminum alternative; check the heater instructions before selecting it.View product and availability →
Atwood water-heater drain plug kitPart 91857For specified older Atwood drain openings; verify the male-thread plug and heater model.View product and availability →
Dometic WH-series drain cap kitPart 92102Female-thread drain cap used on specified WH-series heaters, not an interchangeable Atwood male plug.View product and availability →
Camco 1/2-14 NPT plastic drain plugsPart 11630Two-pack of threaded plugs; compare the removed plug and threaded opening before ordering.View product and availability →
Camco drain-plug and wrench kitPart 11633A service kit for applicable threaded drain plugs; not a replacement for a Suburban anode.View product and availability →
Camco water-heater tank rinserPart 11691Hose-connected tank-flushing accessory; use only as directed for your drained, cooled heater.View product and availability →
Drain and winterizing service notes
Turn off propane and electric heating, allow the water to cool and relieve system pressure before opening the drain. Use the water-heater manufacturer's instructions for draining, inspecting the anode if fitted, flushing sediment and refilling the tank. Never energize a tank-type heater while empty.
For winterization, identify the heater bypass arrangement separately. A water-heater bypass kit routes approved RV antifreeze around the heater; it does not replace the drain plug or anode.
Manufacturer references
NewRVParts products ship from supplier warehouses; in-person product viewing and pickup are not available.