If you are a conscientious homeowner, you probably read the owner’s manuals that came with your appliances.  And, if you’re reading this article, it’s probably because you noticed that the manufacturer of your water heater recommends flushing your unit every six months.  You may have asked yourself, is that really necessary?  Well, perhaps.

You may be wondering why a water heater would need to be flushed.  Under certain conditions, sediment can build up on the bottom of the reservoir.  If the sediment reaches the bottom heating element, it can cause the element to overheat or short circuit.

This can also burn out the lower thermostat.  If either of these conditions occur, then you will need to contact a professional trained in water heater repair, or learn to affect the repair yourself.

To flush or not to flush?

If your warranty requires flushing, then it is a good idea to have the heater flushed by a professional as scheduled, so that you have documentation if you need a replacement or repair.  After your warranty has expired, you may not need to service the unit as often.

If you have an inline water filter, upstream of your water heater, then you probably don’t need to flush your unit every six months.  The same is true if you have a water softener upstream of the unit.

If the water utility experiences frequent line breakages, then you probably should flush the unit twice per year.  If your water is frequently brownish in color, smells dirty, or often smells like chlorine, you should probably flush the unit as recommended.  If you have well water that is high in iron or sulfur, then a twice annual flushing is in order.

How does one flush a water heater?

A typical water heater has upper and lower heating elements and two thermostats.  Near the top of the heater, you will see a drain cock and copper tube running down the length of the heater.  This is the temperature-pressure relief valve.  This is not the valve for flushing your unit.  The drain valve is located on the bottom of the heater and has a fitting for attaching a garden hose.

To start your flush, trip the breaker providing power to your heater.  Then, place masking tape of the breaker, and mark it with the word, “No” if you think someone might turn the breaker back on.  Next, allow the water in the heater to cool down to room temperature, or at least 100 degrees F or lower close the cold-water inlet valve.

When the water is cool, attach a garden hose to the drain valve and run it outside.  Open the valve and let it drain.  Take note of the color of the water coming out of the hose.  If it is brownish or contains sediment, then contact a professional for further inspection.