How to Properly Bleed a Hot Water Heating System

Bleeding your water heater keeps your plumbing in good shape.

Sediment is found in most home water heaters. It is sand or grit or anything that has not dissolved. A small amount of sediment in the bottom of your tank does not typically cause problems. However, without a regular schedule to bleed your tank, you will not know how fast the sediment is building up. Since this sediment can cause problems in your home's plumbing system, draining the tank and flushing it on an annual basis is an important part of your home's maintenance.

Things You'll Need

• Garden hose
• Bucket
• Matches

Instructions

1. Turn off the gas or electricity to your tank. Allow the tank to cool. Depending upon the size of your tank, this could take two hours or more.

2. Close the valve that supplies cold water to the tank. You will probably find it by the top of your tank.

3. Attach the garden hose to the drain valve on the lower part of your tank.

4. Place the other end of the hose where the water can drain without flooding your basement. This could be a sump pump, a floor drain, along the wall of a floating basement, or, if necessary, outside the house.

5. Turn on any hot water tap in your home.

6. Open the tank drain valve and let the water drain. Do not touch the draining water, as it could still be hot. The water running from the tank will probably not be clear as a result of the sediment you are trying to remove. Let the tank drain completely.

7. Open the cold water valve when the tank stops draining so that the water can enter the tank and continue flushing it. Allow the water to flow until the water coming out of the hose is clear. Turn off the cold water valve.

8. Shut the drain valve and take off the hose.

9. Turn off the hot water tap inside the house.

10. Turn on the cold water and fill the tank. Locate the heater's pressure relief valve. This will probably be a pipe coming off the tank, with a shutoff lever.

11. Place the bucket under the pressure relief valve opening and open the shutoff lever. If the water pressure is too high in the tank, some water will be released through this valve. When water is no longer flowing from the relief valve, shut it. If water is still dripping, open the valve again.

12. Turn back on the electric and gas. If you have a gas unit, light the pilot light on the heater, using matches.

Tips & Warnings

• Bleed your tank on a yearly basis. If you are uncomfortable doing the job, contact a licensed contractor.

References

• District of Columbia Water and Sewer Authority: How to Drain Your Hot Water Heater
• Home Additions Plus: How to Drain and Flush a Water Heater