How to flush your water heater

From showering in the morning to running the dishwasher after dinner, homeowners rely on a steady supply of hot water every single day. However, most of us rarely give our water heaters much thought—until something goes wrong. It’s time to change this mindset and start maintaining your water heater, starting with an annual water heater flush.

In this article, we’ll review how you should go about draining and flushing your water heater to keep it running at its best. We’ll then go over some simple ways you can maintain your water heater and extend its functional lifespan.

Why drain and flush your water heater?

All water heater tanks require a regular “flush out” to remove accumulated (and trapped) sediment, mineral deposits, and other forms of buildup at the bottom of the tank. Ideally, as a homeowner, you should flush your water heater tank twice per-year. However, at the bare minimum, an annual water heater flush is an absolute must.

A water heater that goes too long between flushes will:

— Become less energy-efficient, as accumulated sediment and minerals block the heating element from warming the water as effectively.
— Live a shorter life, as corrosive elements will be allowed to build up inside the tank with uninterrupted regularity.

In other words, taking care of regular maintenance for your water heater can end up costing you money, both in the present and in the future.

Can I do this myself, or do I need the help of a professional?

The good news is that a water heater flush is easy for most homeowners to perform themselves, requires relatively common tools, and only takes a few minutes. If you have any experience with doing maintenance around the home, you should be able to take on this project.

However, if you need assistance with this or any other water heater maintenance project, be sure to call our team of experienced plumbers here in Albuquerque and Santa Fe. Since 1928, the team at Wagner has built our reputation on helping local homeowners with their home maintenance needs.

Flushing your water heater

Ready to clean out your water heater and keep it running at its best? Follow these steps to drain and flush your water heater.

Step #1: Turn off the system and cut the power

Start by turning your water heater’s thermostat to off and then, depending on the type of system you have:

— Gas Water Heaters: Shut off the gas line to the water heater.
— Electric Water Heaters: At your home’s breaker box, turn off the power to the circuit the water heater is on. If you’re not sure what circuit the water heater is on specifically, you may want to turn off power to the entire home for this process.

Step #2: Turn off the cold water supply and run hot water

Your water heater has a cold water intake supply line with an adjustable knob near the top of the water heater. You’ll want to shut this off so that no new water is entering the tank. Then, at your kitchen sink or in a bathtub, run the hot water. This latter step is critical to preventing issues with the lines while draining.

Step #3: Position a bucket (or connect a hose)

Near the bottom of the water heater tank is a spigot that controls the outflow of water for drainage purposes. You have two options here:

— You can position a large bucket underneath the spigot and drain directly into the bucket. As you can probably imagine, there’s more water in the tank than your bucket can hold, so you may need to empty the bucket once or twice while draining. As we’ll discuss below, it’s not always necessary to drain the water heater entirely, however.

— You can connect a garden hose to the drainage spigot and run the hose to a bucket. This is especially useful if the placement of your water heater makes positioning a bucket directly beneath difficult.

Either way, the bucket is crucial. As the water drains out of the water heater, you’ll be able to see it in the bucket, which will provide you with a visual key as to when to stop.

Step #4: Start the drainage process

Turn that drainage spigot to open. At first, the water coming out of the water heater and into the bucket will most likely be brown or rust-colored. As you continue draining, this water will eventually start to run clear. If it’s been a while since your last water heater drain, you may need to drain the entire tank to remove all the accumulated sediment.

Step #5: Flush out the remainder

Once you either have clear water or have drained the entire tank of all its water, it’s time to flush. With the bucket and hose still positioned as before, open that cold water supply valve you closed in Step 2. This will allow cold water to run through the tank and into the bucket, carrying any remaining sediment or buildup along with it.

Again, keep an eye on your bucket: as soon as its water is clear, you’re done. You can empty the bucket, detach the hose, close the drainage valve, and turn your water heater back on.

Watch: Step-by-step guide to flushing a water heater

The video below provides a step-by-step visual guide to flushing out sediment from your home’s water heater.

Still not sure how to flush your water heater? If you run into any issues—or want a plumbing professional to help you—be sure to call Wagner!

Should you drain your water heater every year?

Yes, but that’s really just the bare minimum. You should really drain and flush your water heater twice-per-year: once in the spring, and then again in the fall. The reason why comes back to what a water heater is flushing out: minerals and sediment.

As tap water is brought into your water heater tank, it also brings along the natural mineral content of hard water. These minerals fall to the bottom of the tank and begin to accumulate there. That’s a problem, since most tank water heaters feature their heating element at the bottom. The more sediment and mineralization between the heating element and the water, the less efficient and effective your water heater will be.

If you live in an area with hard water, you really need to be draining and flushing out this mineral buildup every 4-6 months. You’d be surprised at how much sediment can collect in the tank over a relatively short amount of time.

What happens if you don’t flush your water heater?

The longer your water heater goes without a drain-and-flush, the more sediment and minerals will accumulate at the bottom of the tank. Eventually, this causes scaling. Ever noticed that hard, mineral buildup on your sink faucets and shower heads? That’s scale: accumulated mineralization. Have enough of that in your water heater’s tank, and you could start running into some significant issues:

— Reduced Efficiency: As scaling collects at the bottom of the tank, your water heater will become less effective at heating the water in the tank.
— Corrosion: If your water heater goes long enough without a proper flush, you could also have corrosion attacking the tank itself, weakening its structural integrity.
— Safety: As we’ll discuss in the section below, your water heater has a crucial pressure-relief valve that prevents pressure from building up in the tank. Scaling can block this valve.

Here’s the bottom-line: you need to be draining and flushing your water heater regularly. But, that’s just the start.

Do water heaters need maintenance?

Yes. In addition to regularly draining and flushing your water heater, you should also test its pressure-relief valve at least once every year.

What is the pressure-relief valve?

If you’ve ever boiled water in a covered pot on a stove, you know that heating water creates steam and pressure. You can see the pot lid, if not heavy enough, jump up-and-down as the pressure (and steam) escape from the enclosed space. This same basic process is playing out inside of your water heater. In most cases, this excess pressure is sent out through your home’s pipes. No harm, no foul. But, when the pressure climbs to unsafe levels, that’s where the pressure-relief valve (sometimes called a T&P valve) is needed.

Most water heater tanks can handle pressures up to 150 psi. That’s a decent amount of pressure—remember, your car’s tires are probably inflated to about 30-35 psi at any given time. When the interior pressure rises above that, the valve automatically opens, releasing some water, steam, and pressure from the tank. You’ll typically notice that your T&P valve has opened if you see a pool of water on the ground below the valve’s discharge pipe.

Checking your T&P valve

At times, this valve can run into issues. It can become stuck, or—as discussed above—interior scaling can block it. To ensure it’s working properly, you should test the T&P valve every year. Put a bucket below the discharge pipe and flip the valve open. You should have water come through the valve, down the pipe, and into the bucket.

If not, there’s something wrong with your valve, and you need to call in a plumbing professional right away.

What is the lifespan of a water heater?

This depends on the type of water heater you have and how well you maintain it. Let’s discuss that first part and address the lifespan differences between gas, electric, and tankless systems.

Lifespan of gas and electric water heaters

On average, electric water heaters last a few years longer than gas ones do:

— Electric Water Heaters: 10-15 Years
— Gas Water Heaters: 8-12 Years

This lifespan difference doesn’t necessarily mean that electric water heaters are the better buy! If you already have a gas line in your home, you’re typically better off with a gas water heater because natural gas is often far cheaper than electricity. In most parts of the country, you’ll pay less to run a gas water heater than an electric one—a principle that also applies, for what it’s worth, to gas and electric furnaces.

Lifespan of tankless water heaters

There’s another class of water heaters worth discussing: tankless water heaters. Also called “demand-type” water heaters, these wall-mounted systems heat water as-needed by running tap water through a series of heating elements.

Tankless systems are more efficient, more convenient, and can last 20-30 years—almost double the lifespan of a standard system! But, the trade-off is that they do cost more to install. However, if you’re looking to make a long-term investment in your home, you should talk to your plumber about tankless systems and whether or not they’re a good fit for your home.

How do I make my hot water heater last longer?

They say age is just a number. For your water heater, however, that number is eventually going to catch up with your system. If you think about what water heaters essentially are—water, metal, heat, pressure—you’ll probably understand why even high-quality water heater tanks only last 15-20 years at most. But, you can help yours get to the top of that lifespan range by:

— Flushing and draining your water heater at least annually, if not 2-3 times per-year.
— Testing the pressure-relief valve at least once per-year.
— Calling a plumber at the first sign of any trouble.

That last item is especially important. If you’re noticing anything strange—from odd sounds to leaks on the tank’s surface—you need to have a plumbing professional out to your home for a closer look. If the issue is caught early, you may be able to save your water heater and get a few more effective years out of it.

Call Wagner for all your water heater maintenance needs

Wagner is the team to call here in Albuquerque and Santa Fe. Our plumbers are water heater professionals. We can help you maintain, repair, or replace your water heater. As always, we’re more than happy to answer all your questions. We’ll help ensure your water heater stays in top condition for years to come.