How to Flush a Water Heater: Basic Flush

Most water coming to your home has sediment in it. Sediment is dirt, silt, and sand that’s in the water coming to your home. The amount of sediment that comes in the water to your home really depends on where the water is coming from. This sediment can cause it to be less efficient, shorten its lifespan or cause parts to fail. Manufacturers recommend doing a water heater flush 1-2 times per year as part of regular maintenance for your water heater.

These instructions are designed to help the do-it-yourself homeowner take care of their own water heater. However, if you read the following instructions and feel like this might be a bigger job than you want to take on, call a plumber you trust to help.

Tools needed: a bucket, a water hose, and a screwdriver

1. TURN OFF WATER HEATER

Because water heaters can be either electric or gas, there are different ways to turn off each.

Electric: shut power off at the electrical breaker panel
Gas: turn the thermostat down to Vacation or Pilot mode

2. SHUT COLD WATER OFF

Find the water lines coming into the top of the water heater and identify which is hot and which is cold. Newer water heaters often have a colored ring around the water lines - red for hot and blue for cold. Some may have words printed that indicate hot or cold. If not, you can actually feel each line coming in and see which one is hot and which one is cold. Once you know which one is cold, follow it up to the shut off valve and close that valve.

flush water heater - shut off cold water

3. CONNECT A HOSE TO SPIGOT ON WATER HEATER

Take your hose and attach it to the spigot near the bottom of the water heater. This is where the sediment typically settles in a water heater. Grab a bucket and put the other end of the hose in a bucket.

4. QUICKLY OPEN VALVE

Use a screwdriver to open the valve on the spigot as quickly as you can all the way. The water coming out of the hose will be hot, so be very careful. The water should shoot out pretty fast at first and then the pressure will drop off after a couple of seconds. After the pressure has subsided, close the valve with the screwdriver.

5. REPRESSURIZE & REPEAT

It’s good to repeat the flushing process a couple of times to get as much of the sediment out of your water heater. To do this, turn the cold water supply on to repressurize the water heater. Shut the cold water off again and open the valve quickly. Repeat this process until you don’t have sediment coming out of the water heater.

6. CLOSE BOTTOM VALVE

Make sure the valve on the spigot is closed and disconnect the hose from the spigot.

7. TURN COLD WATER SUPPLY BACK ON

Make sure to turn the cold water supply back on.

flush water heater - turn cold water back on

8. PURGE ANY AIR FROM THE LINES

Go around your house and open all the hot water taps to purge the air out of the pipes.

flush water heater - purge water from lines

9. TURN THE WATER HEATER BACK ON

Turn the thermostat on the water heater back up to where it was or the breaker back on.

10. WATCH FOR LEAKS

Once everything is turned back on, inspect the water heater and look for any leaks.

Note: If your water heater is old or you have never opened the valve before or have a plastic valve, there is a chance that it may not close all the way and you could end up with a drip or a leak. In that case, you can get a metal cap from a hardware store and put it on there. Or have a plumber put one on the next time you have one out or have them replace the valve (if nothing else is wrong with the water heater).

If you'd rather have someone help you with this, Any Hour Services has plumbers that can do a water heater flush. Book online by clicking button at the top of the screen or call 801-692-0455 to schedule an appointment.