Water heater maintenance checklist
Updated August 2026
The whole water-heater routine is a two-minute look every month (water around the base, a dry relief-valve pipe) plus one flush a year and an anode-rod check every 3 to 5 years. In hard water, halve the flush to every 6 months. Do those few things and a tank comfortably reaches its 8–12-year life instead of rusting out at six.
| Task | Interval | Effort |
|---|---|---|
| Look for water or rust around the base | Monthly | 2 min · DIY |
| Check the relief-valve discharge pipe is dry | Monthly | 1 min · DIY |
| Listen for popping or rumbling as it heats | Monthly | 1 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Flush the tank to clear sediment | 12 months (6 in hard water) | 45–60 min · DIY |
| Test the temperature/pressure-relief (TPR) valve | Yearly | 5 min · DIY |
| Confirm the thermostat is set to 120°F | Yearly | 5 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Check the anode rod, replace if spent | 3–5 years | $50 DIY / $200–300 pro |
| Inspect fittings and connections for corrosion | 3–5 years | 10 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Have a pro run a combustion and venting check | Yearly (gas) | $100–200 pro |
What neglect costs
Sediment on the tank bottom insulates the burner from the water and drags efficiency down 10–25% as it thickens, so you pay more every month for the same hot water. Skip the anode rod and the tank steel corrodes from the inside until the shell splits. When a tank lets go it dumps 40–50 gallons at once and keeps refilling: the average resulting water-damage bill runs $4,000+, and a replacement heater installed is another $1,200–2,000 on top. An hour a year buys almost all of that back.
Leave these to a pro
On a gas unit, the annual combustion and flue-draft check ($100–200, and usually cheaper bundled into an HVAC service call) confirms it is venting exhaust and carbon monoxide safely outside; that one is not a DIY job. Replacing the anode rod on a tank that has never been serviced can also fight back, with a seized hex head and tight overhead clearance, so a plumber earns the $200–300. And if a 10-year-old tank has never been flushed, have it assessed before you drain it: a thick sediment bed can be the only thing currently plugging a pinhole leak.
This whole checklist ships as reminders in OnOtto: every task above, on the right schedule for your home, snooze-proof.
Load this checklist as remindersFrequently asked questions
How do I know if my water heater is about to fail?
Watch for rust-colored hot water, moisture or a rusty ring at the base, popping or rumbling when it heats, and hot water that runs out faster than it used to. Age is the other tell: past 10 to 12 years, budget for replacement even if it still works, because tanks rarely fail at a convenient hour.
Can I flush a water heater myself?
Yes, it is a garden-hose job that takes 45 to 60 minutes: shut off the heat and the cold inlet, run a hose from the drain valve to a floor drain, open a hot tap to break the vacuum, then drain and rinse until the water runs clear. The full step-by-step and the hard-water schedule live on the flush interval page.
What is the TPR valve and why test it yearly?
The temperature and pressure-relief valve is the tank's safety device: if pressure or temperature runs dangerously high it opens and vents rather than letting the tank rupture. Once a year, lift the test lever for a second and let it snap back; you should hear a brief rush of water down the discharge pipe. If it dribbles afterward or does nothing, replace it (a $15 part, or a quick plumber visit).
Does a tankless water heater need this same checklist?
Mostly no. There is no tank to flush and no anode rod, but scale still builds in the heat exchanger, so a tankless unit needs an annual vinegar or descaler flush, especially in hard water where many makers require it for the warranty. Keep the monthly leak-and-vent glance, and watch for error codes, which are its version of the rumble.