Rheem water heaters live 10–14 years on average with no maintenance, and 16–20+ years with the right annual care. The difference is dollars and trouble — $50 in parts over a tank's lifetime vs $1,500+ in unplanned replacement. This page is the complete Rheem maintenance schedule.
Annual maintenance — every year
1. Flush the tank
Sediment accumulates in the bottom of every tank water heater. The sediment insulates the burner from the water (gas) or traps water around the lower element (electric), reducing efficiency and accelerating corrosion. Annual flushing prevents this.
Procedure:
- Shut off power or gas
- Shut off cold-water inlet
- Open a hot-water faucet in the house
- Attach a garden hose to the drain valve
- Open the drain valve and let the tank empty (or about 2–3 gallons of "until water runs clear" if doing a partial flush)
- Close the drain, restore cold inlet, refill while the hot-water faucet runs
- Restore power/gas after the tank is full
If your drain valve is the plastic OEM, upgrade to brass during this same service visit — see our drain valve page.
2. Test the T&P relief valve
Flip the lever fully open for 1–2 seconds. Water should rush out the discharge tube, then stop completely when you release. If it dribbles after release, the valve seat is fouled — try again, replace if still dripping after 3 attempts. See our T&P valve page.
3. Inspect for leaks
Look around the base of the tank for any signs of moisture. Run your hand under the connections at the top of the tank. Check the T&P discharge tube outlet for any signs of recent flow. Catching small leaks early is the difference between a $20 part replacement and a $2,000 basement flood.
4. Visual inspection of the burner chamber (gas only)
Open the burner access door. Look for: spider webs and insect nests (vacuum gently), rust or corrosion on the burner tubes, the pilot flame should be steady and blue-tipped (not yellow or flickering). Replace pilot orifice screen if visible debris is present.
Every 3 years
Inspect the anode rod
The single most important maintenance item. Pull the anode rod out and look:
- Anode still has its original full diameter and the steel core wire is fully encased — anode is good, reinstall
- Anode is 50–75% consumed — note for next inspection
- Anode is more than 75% consumed (steel core wire visible) — replace immediately
See our complete anode rod page for the replacement procedure.
Year 5 milestones
- Replace the anode rod — even if it looks OK, the replacement cost ($40–$80 + an hour) at year 5 typically doubles tank lifespan
- Replace the T&P valve — preventive replacement
- Replace the drain valve (if not already done) — upgrade to brass
- Check elements (electric units) for any signs of weakness
- Inspect the heat exchanger (condensing units) for scale buildup; descale if needed
Year 8 milestones
- Second anode rod inspection — likely needs replacement if not already replaced at year 5
- Begin annual visual tank-shell inspection — look for any rust streaks or visible corrosion at the base
- Check warranty status — note if approaching warranty expiration
- Verify EcoNet/WiFi connectivity (Platinum/ProTerra) and update firmware
Year 12 milestones
- Begin tank-replacement budgeting — most Rheem tanks reach end-of-life around year 12–14
- More frequent visual inspections — monthly is appropriate at this age
- Photograph the data plate for warranty / model number reference (the sticker fades over time)
Tankless-specific maintenance
Tankless (RTGH or RTEX) maintenance differs:
- Annual descaling — required to maintain warranty on RTGH gas tankless and RTEX electric tankless. 60–90 minutes with a descaling pump kit ($60–$120 one-time).
- Inlet filter cleaning — monthly in new installs (debris from new plumbing), then annually
- Vent termination inspection — annually clean PVC vent caps of debris and insect nests
- Firmware updates — via EcoNet app for connected models
ProTerra-specific maintenance
- Air filter clean every 3 months — front-panel filter, restricts airflow if clogged
- Compressor coil clean every 2 years — vacuum the coil fins
- Condensate drain inspection every 6 months — debris in the condensate line backs up into the unit
- Anode check year 4, replace year 6 — ProTerra uses a specialized anode
Bottom line
Annual flush + anode rod replacement at year 5 + T&P replacement at year 5 + drain valve upgrade = $80 in parts over 5 years and roughly $400 in DIY labor. Skip these and your $1,000 Rheem becomes a $2,000 expense at year 12 instead of year 18. The math is unambiguous. For specific parts, see our Rheem parts directory.