Drain the water heater and test its relief valve
Sediment shortens tank life; the relief valve is the safety that stops a tank from over-pressurizing. On a tank over 10 years old, or one not drained in years, flushing can expose worse problems (Energy Trust): a pro may be wiser.
Who: You can do it yourself, or have a plumber do it. Tank models only.
How often: Tank models: after the first 6 months, then yearly; about every 6 months with hard water; lift the relief valve lever yearly; the valve’s label gives its own inspection schedule. For: the water heater.
Safety first
- First let the hot water run until it’s cool, so you don’t get burned.
- Electric: never turn the power on until the tank is full (it can burn out the elements).
- The relief valve throws hot water: check that its pipe ends somewhere safe and isn’t capped.
- A tank over 10 years old: flushing can expose other problems.
What you need
- A garden hose.
- A floor drain, the outdoors, or buckets.
Time: A few hours, plus cooling time; the tank takes 1-2 hours to reheat after.
The part, and finding the right one
- Relief valve (water heater). The safety valve on the top or side; replaced if it won’t release or keeps dripping after a test. Its rating is on its own tag; a plumber replaces it.
On a home’s record, each piece of equipment’s page links its manual and a search for its parts by brand and model. All filters and parts
How to do it
- Electric: breaker off. Gas: gas off at the manual shutoff (or the pilot setting, per your label), and power off on a power-vent model.
- Open a hot tap and run it until the water is cool, 10 minutes or more; or let it cool overnight.
- Close the cold supply valve on top.
- Put a hose on the drain valve at the bottom, with the other end at the drain; open the drain valve and a hot tap in the house.
- Won’t drain? Sediment clogs the valve; try stepping on the hose to push water back. Still nothing? Stop and call a plumber.
- With the drain open, open the cold supply for a moment, until the water runs clear and no more sediment comes. Close the drain and remove the hose.
- Refill: cold supply on, hot tap open. Electric: wait until the hot tap runs full for 3 minutes, so the air is out. Then turn the power or gas on as the label says.
- Relief valve: look at the discharge pipe first. Lift the lever; water should flow freely. Watch the pipe end for a drip after it drains. No water flows? Turn the power off and call a plumber.
Normal
- Rumbling or popping: sediment; flush it.
- Sizzling on a cold first light: condensation.
- A rotten-egg smell: harmless bacteria (see the anode rod).
Needs attention
- A small, steady drip from the relief valve: house water pressure too high (50-60 psi is the target), or an expansion tank is needed.
- A large, hot discharge: overheating.
- Water on the floor from the tank.
Call a plumber if
- The tank won’t drain.
- The relief valve won’t flow.
- The relief valve keeps dripping after the pressure, expansion tank and debris checks.
- Leaks, odors, or uneven heating.
- It’s time for the valve itself to be inspected, on the schedule on its label.
Keep
- The manual’s own maintenance log (“Maintenance performed: Date”).
Keep track of it
Add your home to My homes: each piece of equipment gets this on its own schedule, with “Mark done” and reminders you can turn on.
Sources
Where the makers differ:
- State, A. O. Smith and Rheem print owner steps; Bradford White says a qualified technician.
- How long the hot tap runs after refilling an electric tank, before the power goes back on: 3 minutes so the air is out; Energy Trust says 15.
- Bradford White: lift the relief valve lever several times until it seats without leaking.
- How often the relief valve itself is inspected: State says every 2-4 years, and also says 5; Watts says every 3.
Your owner’s manual comes first: where it says something different for your model, follow it.
Still stuck?
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