How to Drain a Hot Water Heater

How to Drain a Hot Water Heater

How to Drain a Hot Water Heater

Is your hot water heater being fickle? Maybe the warm water runs out too quickly or you’re getting some noisy rumblings from its general direction. Like an aging relative, our hot water heaters demand care and maintenance. And one of the best ways to keep them working their best is to drain them regularly.

I know, I know. Draining a water heater sounds about as fun as cleaning the gutters or organizing the hall closet. But keeping your water heater drained means you’ll spend less money and time dealing with repairs down the road. So, let’s dive into the how-to drain a water heater. Together, we can make this about as fun as plunging a toilet! (Which is still more fun than organizing that closet.)

Why Drain Your Hot Water Heater?

Why Drain Your Hot Water Heater?

I like draining as giving your water heater a little spa day. It’s a chance for it to release all the built-up gunk and sediment to keep working in tip-top shape.

See, over time your water heater collects all sorts of lovely things from the water running through it:

  • Mineral deposits like calcium and magnesium
  • Rust particles
  • Bits of silica sand and dirt
  • Other debris

This sediment eventually builds up along the bottom of the tank. And too much sediment buildup causes all sorts of problems:

  • Inefficiency: Sediment acts as an insulator, preventing heat from properly transferring to the water. So, your hot water heater has to work harder to heat the same amount of water. Cha-ching! Higher energy bills.
  • Noisy operation: Excess sediment can cause rumbling, cracking, and popping noises as sediment shifts around. It’s like your hot water heater has a stomach ache.
  • Tank failure: Left long enough, thick layers of sediment can actually cause leaks or tiny fractures in the tank itself. No one wants an emergency water heater replacement!
  • Burner failure: Sediment buildup can block the thermostat, causing it to read the water temperature incorrectly. That leads to uneven water heating…or the failure of the heating components altogether.

So like an annual check-up at the doctor, periodic draining helps prevent all these problems. A well-maintained water heater = a happy home with no unexpected ice-cold showers!

When to Drain Your Hot Water Heater

Most manufacturers recommend draining your water heater tank every 6 months to a year. But you might need to do it more or less often depending on:

  • Water hardness: The mineral content in your water. Hard water leads to heavier sediment buildup.
  • Water usage: Are you draining a household hot water heater or a commercial one? High volume usage = more debris buildup.
  • Type of water heater: Tankless water heaters need less regular draining than conventional tank style heaters.

A good way to gauge is to drain and flush the tank when you notice pressure and temperature changes during your showers. Or if sediment has built up over an inch thick along the bottom.

You’ll also want to do a full flush if you smell rotten eggs or sulfur coming from the hot water. This can indicate bacteria growth inside the tank. Draining flushes out the bacteria.

How to Drain a Hot Water Heater: A Step-by-Step Guide

Ready to give your hot water heater its periodic spa treatment? Let’s look at the step-by-step process.

The basic process is straightforward. We’ll:

  1. Turn off power and water lines
  2. Attach a hose to drain the tank
  3. Open the pressure relief valve
  4. Flush the tank
  5. Refill once draining finished

I’ll also cover safety tips and some extra steps for draining gas and electric water heaters.

What You’ll Need:
  • Adjustable wrench
  • Garden hose (or catch bucket, if draining into a sink)
  • Replacement relief valve (optional)
  • Funnel (optional, for flushing tank)

Step 1 – Turn Off Power to Electric Water Heaters

Start by switching off electrical power to an electric heater at your home’s breaker box. This ensures the heating elements don’t turn on while draining.

For gas water heaters, skip to step 2 since there’s no power to turn off.

Step 2 – Turn Off the Cold Water Supply Line

Locate the cold water shutoff valve entering the top of the tank. Use the adjustable wrench to turn the valve clockwise until it’s completely closed.

Closing this valve keeps new water from entering during draining.

Step 3 – Attach Drainage Hose

Find the tank drain valve near the bottom of the water heater. It might be a standard hose bib, petcock valve, or ball valve.

Attach your drainage hose by screwing it onto the drain fitting. Make sure the other end of the hose reaches outdoors or to a sink.

Place the end of the hose in your drainage location. Then slowly open the tank drain valve by turning it counterclockwise. Position a bucket under the end of the hose to catch any initial debris discharge.

Gravity will drain the water out through the hose. Pretty neat trick, huh?

Step 4 – Open the T&P Relief Valve

Near the top of the tank you’ll find a long pipe capped with a pressure and temperature relief valve. This T&P valve serves as a crucial safety release – it pops open if pressure or heat get too high inside the tank.

While the tank drains, open the T&P valve lever slightly. This allows air to enter and water drains out faster through the hose.

Caution – Hot water will come spraying out! So make sure to direct the stream away from yourself using the drainage hose.

You can also open any hot water faucets inside the house for quicker draining. Just be prepared for a burst of air and water when the tank fully drains.

Step 5 – Flush Out Sediment

For an even deeper clean, flush the water heater after it finishes draining. This helps wash out residual sediment and scale sitting loose along the bottom of the empty tank.

If your T&P valve has a drain hose attached, simply remove the cap on the drain hose so it diverts water outside. Then use a funnel to pour water into the T&P valve or cold water inlet.

If your valve doesn’t have a drain tube, here are a couple options:

  • Attach a hose to drain valve again and flush water through tank. Drain it outside if possible.
  • Flush through the tank a few gallons at a time by refilling and draining via the drain valve.

Flushing a couple times clears out quite a bit of sludge!

Step 6 – Inspect Components and Refill the Tank

With the tank emptied, shine a flashlight inside and visually inspect the interior. Check for any cracks, heavy corrosion, or leaks indicating a compromised tank.

You can also remove and inspect heating elements or the anode rod. Replace either if worn. The anode rod especially protects against corrosion but wears out over time.

Finally, close the drain valve and refill the tank by turning the cold water valve back on. When water flows full pressure from the hot taps, you’ve refilled the tank completely. Plug electric water heaters back into power.

That’s it – draining complete! Not so bad, right? With an annual draining, your hot water heater will thank you with years more of reliable service.

Draining Gas and Electric Water Heaters

The general process covers the basics for all heaters. But gas and electric water heaters each have a couple extra steps worth covering:

Gas Water Heaters

First, the pilot light will go out when draining a gas heater. So you need to relight it once finished refilling the tank.

Refer to manufacturer instructions for proper pilot lighting technique. Usually you:

  1. Remove the outer burner access panel
  2. Put the control knob in the pilot position
  3. Repeatedly push the igniter button while holding a lit match or lighter wand next to the pilot.
  4. Once the pilot ignites and stays lit, hold the knob pushed in for 30 seconds.
  5. Turn the knob to the “on” position.

This ignites the main burner again once the tank refills.

You should also drain and refill the expansion tank on a gas water heater system. The expansion tank maintains safe water pressure levels.

To drain it:

  1. Shut off the cold water inlet valve
  2. Open the tank drain valve
  3. Let the expansion tank fully drain, then close the drain valve
  4. Turn the water supply back on to refill

This prevents the buildup of sediment and bacteria inside the small tank.

Electric Water Heaters

Scale buildup on electric heating elements further reduces hot water efficiency. So while draining, remove and descale elements by soaking in white vinegar or scaler solution. Wiping with a non-abrasive pad also cleans them.

Rinse and reinstall once descaled. Take note of element wattage or resistance so you can purchase the proper replacement if needed.

Draining Gas and Electric Water Heaters

Draining Safety Tips

Working with water and electricity does require some basic precautions. Keep these safety tips in mind:

  • Wear rubber-soled shoes and keep the floor dry while draining to avoid slipping or electric shock.
  • Check that all power is OFF for an electric heater before draining and flushing.
  • Turn off the gas supply or put a heater in “pilot” mode before relighting it.
  • Direct the end of the T&P valve discharge hose away from electrical panels or components.
  • Avoid exposure to hot draining water.
  • Allow heating elements to fully cool before disassembly.

You might also consider replacing the relief valve while draining the tank. The lever or seat can become mineral-blocked or worn over time. A faulty T&P = risk of dangerous pressure overload.

So consider picking up a relief valve replacement matching your heater specifications beforehand Just make sure to clean mineral deposits off the valve seat port when swapping it out.

Know When to Call A Pro

While routine hot water heater maintenance is totally DIY-friendly, more serious issues are best left to the professionals. Call a technician if you encounter:

  • Leaking or heavily corroded tanks
  • Faulty T&P valves that don’t reseat or continue to drip
  • Sediment too thick to flush out yourself
  • Burner or element failure
  • Other major component concerns

Most plumbers can replace heating elements, anode rods, relief valves, and other typical water heater parts. Or help determine if a full replacement is needed.

Think of it like changing the oil in your car yourself versus needing a transmission rebuild. Major repairs warrant an expert eye!


How often should I drain my hot water heater?

Drain your hot water heater at least once a year to remove sediment buildup and maintain efficiency.

What tools do I need to drain a hot water heater?

Gather a garden hose, screwdriver, and a bucket to safely drain water and sediment from the heater.

Can I drain a hot water heater while it’s in use?

No, turn off the heater and let it cool before draining to avoid burns and ensure safe maintenance.

How do I locate the drain valve on my hot water heater?

Find the drain valve near the bottom of the tank, typically connected to a hose bib. Use a screwdriver to open it.

Why is it important to drain a hot water heater?

Regular draining prevents sediment buildup, maintains heating efficiency, and extends the lifespan of your hot water heater.

Last Thoughts

Regularly draining your hot water heater is a simple yet crucial maintenance task that can significantly extend its lifespan and ensure optimal performance. By knowing how to drain a hot water heater and removing sediment buildup, you prevent inefficiency, noisy operation, and potential tank failure. This DIY spa day for your water heater eliminates mineral deposits, rust particles, and debris, promoting energy efficiency and preventing costly repairs. A French Drain is a drainage system designed to redirect water away from a specific area, typically using a perforated pipe surrounded by gravel; while the process may seem daunting, following the step-by-step guide ensures a smooth and effective draining experience. Ultimately, investing time in this routine maintenance task will save you money and the inconvenience of unexpected hot water heater issues, providing the care your water heater deserves for a consistently reliable hot water supply.

Post Comment