USA Water quality is supported by its audience. If you buy something through our links, we may earn money from our affiliate partners. Learn more

How to Drain AO Smith Water Heater? – 5 Easy Steps

Fact checked by Stephen Conklin

how to drain ao smith water heater

You know how to drain AO Smith water heater units if you can flip a switch, twist a knob, open a faucet, and connect a hose to a port. That’s how easy draining an AO Smith water heater (or any other brand) is.

Performing the water heater drainage process once every six months is crucial to maintaining the appliance’s optimum functioning. It allows you to enjoy more efficient water heating while relishing the benefits of a warm, relaxing shower and more sanitized dishes and clothes.

So, how do you empty a water heater from AO Smith? Please read on.

Table of Contents

Step-by-Step to Drain AO Smith Water Heater


What to Prepare


The resources for this maintenance activity are minimal, requiring only a garden hose long enough to reach a floor drain or the backyard.

You might also want several buckets if the hose is insufficient.

Step 1. Prepare the AO Smith Water Heater


We recommend reading your AO Smith water heater owner’s manual for detailed instructions on draining the appliance. You can also flush AO Smith water heater units by observing the document’s guidelines. Don’t fret if you don’t have the User Guide. We’ll outline the steps here.

  1. Look for a straight handle or a wheel at the pipe above the AO Smith water heater. Turn this device clockwise to prevent cold water from entering the tank.
  2. Electric AO Smith water heaters require switching off the circuit breaker supplying electricity to the appliance. This action prevents burning out and damaging the heating elements.
  3. Look for a small box at the side of a gas-powered AO Smith water heater. It should have a control knob on top or the front. Twist this until the indicator points to the “PILOT” setting.
  4. Alternatively, you can follow the water heater’s gas supply line until you find the main gas valve controlling fuel to other gas-powered appliances in the home. You can turn this off.

Step 2. Allow the Water to Cool


Please don’t forget this step, it’s for your safety.

Working with water heaters exposes you to thermal injuries, although most water heaters only heat the water between 120 and 140 degrees Fahrenheit. You don’t want to open the plastic drain valve with hot water flowing out.

  • Schedule the water heater draining activity at night, so you can sleep over it and continue the procedure when you wake up the following morning.
  • You can take a shower, use a hot water faucet, or run the dishwasher to empty the tank.

Step 3. Connect the Garden Hose to the AO Smith Water Heater’s Drain Valve


An effective AO Smith water heater sediment removal requires emptying the now-cold water into appropriate places. For example, you can drain the water into a floor drain, the garden, or other areas with adequate drainage.

  1. Look for a small tube near the AO Smith water heater’s bottom. It connects to a bulkier component with a straight handle or a rotatable wheel. This object is the AO Smith water heater’s drain valve.
  2. Connect one end of the garden hose to the drain port.
  3. Extend the hose and place its other end on your preferred drainage area (i.e., the garden or floor drain). Alternatively, use several buckets as water containment units.

Step 4. Drain the Water


This step for draining sediment from an AO Smith water heater is one of the easiest. The following procedures will underscore our point.

  1. Go to a floor directly above the AO Smith water heater and look for the closest hot water tap. This step applies only to water heaters in the basement.
  2. If you have a single-floor home, go to the hot water tap closest to the AO Smith water heater.
  3. Turn on the tap to reduce pressure within the hot water tank.
  4. Return to the AO Smith water heater and open drain valve. You’ll need about 20 to 60 minutes to drain the tank, depending on its capacity.

Step 5. Reverse the Process and Finish Up


We recommend keeping the drain valve open to flush sediments out of the AO Smith water heater. After that, open the water inlet valve (the wheel or straight handle at the tank’s top) to flush and clean the tank’s interior. Otherwise, you can observe the following procedures.

  1. Close the AO Smith water heater drain valve and any running hot water fixture.
  2. Disconnect the garden hose from the drain port.
  3. Turn the water inlet valve wheel or straight handle counterclockwise to restore the water supply to the hot water tank.
  4. Fill the AO Smith water heater.
  5. Twist the gas control knob to “ON” or flip the circuit breaker switch to the water heater.

We found this YouTube video from 92dome.crypto showing homeowners how to remove sediments from their AO Smith water heaters by draining the hot water tank. It’s worth checking out.


You can use this guide on how to drain AO Smith water heater units to help relatives, neighbors, friends, and acquaintances who might have problems emptying their respective water-heating appliances. Although this article is for AO Smith units, the steps apply to other brands like Rheem.

Draining water heaters is essential to eliminate sediments and other debris interfering with the appliance’s optimal functioning. You can guarantee your AO Smith water heater’s longevity and optimum performance if you adhere to this five-step process at least every six months.

5/5 - (1 vote)