Most Rheem water heater service calls trace to one of a dozen common parts. This page is the parts directory for residential Rheem units — what each part does, the typical Rheem part number, current pricing, and how DIY-friendly the replacement is. For specific symptoms, see our troubleshooting hub. For warranty-covered replacements see the warranty page.
Most-replaced Rheem parts at a glance
| Part | Typical Rheem part # | Cost | DIY? |
|---|---|---|---|
| Thermocouple (gas pilot sensor) | SP12090A | $25–$40 | Yes — 30 min |
| Anode rod (sacrificial) | AP12659C / universal 42" | $40–$80 | Yes — 60 min |
| Heating element (electric) | SP10874MN (4500W) | $30–$60 | Yes — 60 min |
| Thermostat (upper/lower) | AP12889B / AP12889C | $25–$45 | Yes — 45 min |
| Gas control valve | SP21176A (varies by BTU) | $180–$320 | Pro — gas leak risk |
| Pilot assembly | SP12176C / SP15013 | $60–$120 | Yes — 60 min |
| Drain valve | SP12126A (plastic) / brass upgrade | $10–$25 | Yes — 30 min |
| T&P relief valve | Watts 100XL 150 psi 210°F | $20–$30 | Yes — 30 min |
| Igniter (condensing units) | SP20303B | $40–$75 | Yes — 45 min |
| Flame sensor | SP15103A | $30–$50 | Yes — 30 min |
Where to source Rheem parts
Rheem distributors (most authoritative — direct line to Rheem inventory): find one through Rheem.com's dealer locator. Best for warranty parts and specialty items.
Big-box retailers (Home Depot, Lowe's) carry the most common parts — thermocouples, anode rods, T&P valves, drain valves, generic 4500W elements. See our Home Depot Rheem hub and Lowe's Rheem hub for what each retailer typically stocks.
Amazon stocks most Rheem service parts at competitive pricing — fast for non-emergency replacements. Verify the part number against your unit's data plate before ordering.
Specialty parts (gas valves, control boards, heat exchangers): typically only through Rheem-authorized service network. Don't try to source these on the open market — counterfeits are common and create real safety risks for gas-side parts.
How to identify the right part
Every replacement starts with the data plate on your unit. Pull these three numbers:
- Model number (top of data plate, e.g. XG50T12HE40U0)
- Serial number (line below model number)
- BTU input (for gas valves and pilot assemblies — different BTU classes use different parts)
Rheem distributors and the customer service line (1-800-621-5622) cross-reference these to the right part number. Save guessing for thermocouples and T&P valves where universal compatibility is common.
Universal vs Rheem-specific parts
Universal-compatible (work across Rheem and other brands): thermocouples, anode rods (42" hex-head is standard), T&P valves, drain valves, 4500W heating elements, igniters in many cases.
Rheem-specific: gas control valves, pilot assemblies (the precise burner-port geometry matters), electronic control boards on EcoNet units, ProTerra compressor parts, RTGH tankless heat exchangers.
DIY vs pro — the safety line
Safe DIY territory: anything you can access without disconnecting the gas line, draining and refilling the tank, or opening the burner chamber on a gas unit. Element swaps, anode rod swap, T&P replacement, drain valve, thermostat — all reasonable DIY for handy homeowners.
Pro-required: gas control valve replacement (gas line disconnect = leak risk), heat exchanger work on tankless, ProTerra compressor or refrigerant work, anything requiring burner combustion adjustment after the part is installed.
Common part-specific guides
- Anode rod replacement — the highest-leverage maintenance item; doubles tank life when done at year 5
- Heating element replacement — most common DIY repair on electric Rheem
- Thermocouple replacement — the most common gas-Rheem fix
- Pilot assembly — when thermocouple replacement doesn't solve "pilot won't stay lit"
- Thermostat replacement — upper vs lower; how to tell which has failed
- Gas control valve — when it's worth replacing vs replacing the whole unit
- Drain valve — upgrade from plastic to brass is one of the cheapest upgrades you can make
- T&P relief valve — annual test + replace every 5 years
Bottom line
The Rheem residential parts catalog is small, well-documented, and most parts are inexpensive. The high-leverage items are the anode rod (replace at year 5 to double tank life) and the thermocouple (the most common failure on gas tanks). For warranty-covered replacements call Rheem first; for out-of-warranty work the distributor + Amazon combination covers most needs. For active troubleshooting see our troubleshooting hub.