Home Improvement Tip: Flushing Out Hot Water Heater Problems


I am only a recent home owner. Until the market crashed and I got married, there was no way I could afford a house.  Now 2+ years later I am enjoying–make that enduring–all the things that make home ownership different than apartment living; both good and bad.

Take for example the water heater… When we moved in, our house was nearly the exact same house the previous owner had moved into in 1954.  Within the last ten years, before moving off into an assisted living facility, all the appliances had been updated–except the furnace.  So I didn’t give any thought to the water heater.  Then I started to hear things.  Strange gurgling came from the closet when my wife turned on the kitchen faucet.  In fact turning on a faucet anywhere in the house caused a sound like the stomach of a hungry giant from the water heater’s home in the closet.

I also grew tired of having to take apart the shower head every 90 days and clean out the crud.

It was time to flush the hot water heater and clean out the crud in the tank.

Water heaters build up all sorts of stuff inside their tanks over the years:  There is rust and other sediment that can come in from the city pipes.  Also lime, which is dissolved in most water and which come out when the water is heated.  And minerals caused by interactions between the pipes and the water itself.  Because of this they need to be drained, and/or flushed periodically.

If you leave the crud in the tank you will be wasting gas or electricity (and therefore money) because you are losing a percentage of efficiency by heating up the crud–which you can’t shower with.  If you don’t clear the crud, over time it can get so bad the only option is replacing the heater, and that ain’t cheap.

The simple way to do this requires a garden hose, otherwise you have a bucket brigade to look forward to.

- Attach the hose to the thing on the bottom of the tank that looks like a hose spigot. 

- Run the other end of the hose out the nearest door or window, or down a drain (if you can get it outside you can use it to water the lawn, but careful you don’t scald anything).

- Turn off the heat source, either by turning the gas valve to “Pilot” or shutting off the electrical breaker.

- Turn off the cold water flowing into the tank.

– Open the drain spigot.

– Turn on the hot water at the nearest faucet to allow air into the system so the tank can drain.

- Go have a look and make sure hot cruddy water is flowing out the end of the hose.

- If clean, clear water is flowing, you’re pretty much finished.  Just let it run for 5 minutes and undo the earlier steps in reverse order, and you’re done.

- If no water is flowing, shut off the faucet you opened for air, and turn the cold water supply back on to the tank.  This should clear out any crud in the drain valve and get the water flowing again.

- Close the drain valve, open the supply valve and relight the pilot, or turn on the breaker.

This is also a good time to test the pressure relief valve.  That’s the thing near the top of the tank that looks like a hose spigot.  Instructions for testing this should be on the tank itself.

My tank was really cruddy.  I had to flush the drain valve with the fresh water supply at least three times, and it still barely wanted to drain.  I put it all back to rights, ran the hot water faucet in the bathroom to clear the rust and air bubbles in the line and called it a night. 

If the gurgling giant is still hiding in the closet, I will try this again in a few days.

Any home repair tips you’d like me to cover in the future? Let me know in the comments and I just might blog about it!

Comments (3)

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  1. chrismason57

    4 years ago

    Very helpful. What if your water heater is only a year or so old? Next topic: hard water and what to do about it.


  2. brwood

    4 years ago

    If you want to treat your hard water, get a water softener installed. Sears has them for 10% off with code at the moment: //www.savings.com/z0uy

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