How to Drain a Water Heater: A Step-by-Step Guide
If your water heater has been running for a few years without much maintenance, there’s a good chance some sediment has collected at the bottom of the tank. Learning how to drain a water heater can help remove some of that buildup and may help your water heater continue operating efficiently.
The process isn’t especially complicated, but there are a few important safety precautions to follow. Water inside the tank can be extremely hot, and electric water heaters can be damaged if the power is turned back on before the tank is completely refilled.
Below, we’ll walk through how to drain a traditional tank-style water heater, why you may want to do it, and when it makes more sense to call a plumber.
Why Do You Need to Drain a Water Heater?
Over time, minerals, rust particles, and other debris can settle at the bottom of your water heater tank.
Think of the tank as a large settling basin. Every time water enters the heater, small amounts of minerals and sediment can enter with it. Eventually, some of that material settles instead of leaving through your hot water pipes.
Sediment buildup may contribute to:
- Popping or rumbling noises
- Reduced water heater efficiency
- Less available hot water
- Longer heating times
- Clogged or slow drain valves
- Additional wear on the water heater
Bradford White explains that sediment and foreign particles can accumulate in storage tanks over time and recommends periodic draining as part of water heater maintenance. Bradford White’s guide to draining a water heater
If your water heater has started making strange noises or isn’t performing like it used to, sediment isn’t the only possible culprit. JLR Plumbing also provides professional water heater repair in Spokane for problems involving heating elements, thermostats, burners, valves, sediment buildup, ignition systems, and other components.
How to Drain a Water Heater
Before starting, check the manufacturer’s instructions for your particular water heater. The exact procedure can vary depending on the model.
You’ll generally need:
- A garden hose
- A suitable floor drain or safe outdoor drainage location
- Gloves
- A flat-head screwdriver if required by your drain valve
Most importantly, remember that the water coming out of the tank may be extremely hot.
1. Turn Off the Water Heater
The first step is shutting down the water heater.
For an electric water heater, turn off the appropriate breaker at your electrical panel.
This is especially important because electric heating elements can be damaged if they operate while the tank is empty.
For a gas water heater, follow the shutdown or maintenance instructions provided by the manufacturer. Depending on the model, this may involve turning the gas control to a pilot or off position.
Don’t simply guess. Check the label or owner’s manual for your specific unit.
2. Turn Off the Cold Water Supply
Find the cold-water supply line entering your water heater.
There should normally be a shutoff valve on this line.
Turn the valve off so additional water doesn’t continue entering the tank while you’re attempting to drain it.
3. Connect a Garden Hose to the Drain Valve
Near the bottom of a traditional tank water heater, you’ll find a drain valve.
Attach a garden hose securely to the valve.
Run the other end of the hose to an appropriate drain or another location where the water can safely discharge.
Remember that the water may still be hot enough to cause burns or damage some surfaces, so be careful where you route the hose.
4. Open a Hot Water Faucet
Open a hot water faucet somewhere in the house.
This helps allow air into the plumbing system as water leaves the tank.
If you skip this step, the tank may drain much more slowly or have difficulty draining altogether.
5. Open the Drain Valve
Carefully open the drain valve at the bottom of the water heater.
Water should begin flowing through the garden hose.
Keep an eye on both ends of the hose to make sure there are no leaks and that the discharged water isn’t creating a problem.
Depending on the size of your tank, water pressure, sediment level, and drain valve condition, draining can take some time.
What If the Water Heater Won’t Drain?
One common problem homeowners encounter is opening the valve and getting little or no water.
Heavy sediment buildup can clog the drain valve.
You may notice:
- Water only trickling from the hose
- Water starting and stopping
- No water coming out at all
- Small chunks of sediment exiting the hose
At this point, avoid aggressively poking objects into the drain valve or attempting to disassemble a pressurized water heater.
A severely clogged drain can indicate that a considerable amount of sediment has accumulated inside the tank.
If that happens, having the heater professionally inspected may be the safer option.
JLR Plumbing specializes in diagnosing traditional gas and electric water heaters throughout Spokane and the surrounding communities.
Draining vs. Flushing a Water Heater
Although the terms are sometimes used interchangeably, draining and flushing a water heater aren’t exactly the same thing.
Draining means removing the water currently inside the tank.
Flushing goes a step further by running clean water through the tank to help carry additional sediment out through the drain valve.
After the initial tank has drained, manufacturer instructions may recommend briefly reopening the cold-water supply while the drain valve remains open.
The incoming water can stir up sediment remaining at the bottom of the tank and push it through the hose.
This process may be repeated until the water coming from the drain runs relatively clear.
Bradford White’s maintenance instructions, for example, describe flushing several gallons through the tank and repeating the process until the discharged water runs clear.
How Often Should You Drain a Water Heater?
There’s no perfect schedule for every home.
How quickly sediment accumulates depends on factors such as:
- Local water conditions
- Mineral content
- Household water usage
- Water heater design
- Tank age
- Manufacturer recommendations
Some manufacturers recommend periodic or annual tank flushing for certain models. Bradford White notes that routine maintenance can help maintain efficient and safe water heater operation and recommends following the maintenance instructions for your specific model. Bradford White water heater maintenance recommendations
If you don’t know when your water heater was last serviced, that’s worth considering—especially if the tank is making unusual noises.
How to Refill a Water Heater After Draining It
This part is extremely important.
Do not turn an electric water heater back on while the tank is empty.
Once you’re finished draining or flushing:
- Close the drain valve.
- Remove the garden hose.
- Make sure the drain valve isn’t leaking.
- Open the cold-water supply valve.
- Leave a nearby hot water faucet open.
- Allow the tank to fill.
- Wait until water flows steadily from the open hot-water faucet.
- Close the faucet.
- Check around the water heater for leaks.
- Restore power or return the gas water heater to normal operation according to the manufacturer’s instructions.
Air may sputter from the faucet while the tank refills. That’s normal.
The important thing is making sure the tank is completely full before an electric water heater’s heating elements are energized.
Can Draining a Water Heater Fix Noisy Operation?
Sometimes.
Sediment at the bottom of a tank can contribute to popping, cracking, or rumbling sounds.
When the burner or electric heating elements heat the water, trapped water beneath or around mineral deposits can create noise.
Removing sediment may reduce the problem.
However, strange noises aren’t automatically a sediment issue. They can also indicate other water heater problems.
If your water heater is leaking, producing inconsistent hot water, running out of hot water too quickly, or making unusual noises, consider having it inspected rather than assuming flushing will solve everything.
JLR Plumbing’s Spokane water heater repair service can help determine whether the heater needs maintenance, a repair, or replacement.
Should You Drain an Older Water Heater?
This is where DIY water heater maintenance can become a little more complicated.
If an older tank hasn’t been drained in many years, suddenly disturbing a large amount of accumulated sediment isn’t always as straightforward as flushing a relatively new water heater that has received regular maintenance.
Older drain valves may also become brittle, clogged, or difficult to reseal after being opened.
If you have an aging water heater that has never been maintained, it may be worth having a plumber inspect the system before attempting a major flush.
And if the tank itself is leaking, draining it won’t repair the problem.
A leaking tank generally requires replacement.
JLR Plumbing provides water heater installation and replacement in Spokane for homeowners who have reached the point where repairing or maintaining an older tank no longer makes financial sense.
When Should You Call a Plumber?
Consider calling a professional if:
- The drain valve won’t open.
- The drain valve becomes clogged.
- The valve leaks after draining.
- You see corrosion around the tank.
- Water is leaking from the tank itself.
- Your water heater continues making loud noises after maintenance.
- Hot water runs out unusually quickly.
- You aren’t comfortable working around hot water, electricity, or gas.
- You’re unsure how to safely shut down or restart your water heater.
Water heater maintenance should never put you or your home at unnecessary risk.
Need Water Heater Help in Spokane?
Knowing how to drain a water heater can make routine tank maintenance easier, particularly when you’re trying to remove sediment that has accumulated over time.
But draining the tank isn’t a cure for every water heater problem.
If your water heater is leaking, making unusual noises, struggling to produce enough hot water, or simply getting old, JLR Plumbing can help determine whether maintenance, repair, or replacement is the best option.
JLR Plumbing specializes in water heater installation, replacement, repair, and tankless water heater services throughout Spokane, Spokane Valley, Liberty Lake, Medical Lake, Airway Heights, Mead, Cheney, and surrounding Spokane County communities.
Learn more about JLR Plumbing’s Spokane water heater services or call 509-472-5655 to schedule service.
Frequently Asked Questions About Draining a Water Heater
How long does it take to drain a water heater?
The exact time varies depending on the size of the tank, drain valve, water pressure, hose setup, and how much sediment is inside. A badly clogged drain valve can dramatically slow down the process.
Do I need to turn off the water heater before draining it?
Yes. Electric water heaters should have their power disconnected before draining, and gas water heaters should be shut down according to the manufacturer’s instructions.
Should I turn off the water supply when draining a water heater?
Yes. The cold-water supply is normally shut off during the initial draining process.
Can I drain a water heater with a garden hose?
Yes. Traditional tank water heaters generally have a drain valve near the bottom of the tank that accepts a standard garden hose.
Why is my water tank not draining through the hose?
Sediment may be blocking the drain valve. A clogged drain is particularly common in tanks that haven’t been flushed or maintained for a long time.
Is flushing a water heater the same as draining it?
Not quite. Draining removes the water from the tank. Flushing uses fresh water to help carry additional sediment and debris out of the tank.
Do you have to refill a water heater before turning it back on?
Absolutely. An electric water heater must be completely refilled before power is restored. Operating electric heating elements without water can damage them.