Flushing a water heater

[jasonl]

Hi all.

I need help on differing opinions here. I'm going to flush the sediment out of my water heater and need to know which way to do it is correct.

I know the obvious steps are:

Shut off the power supply
connect a hose to the drain valve
Run the hose either outside or to a bathtub.

Here's the variations in procedure.

1. Turn off the water supply, open up a hot water faucet (for air displacement), open the drain valve, let it drain. Close the drain valve and fill the tank. Repeat as necessary.

or...

2. Leave the water supply on. Open the drain valve slightly and let the water run until it's clear.

The argument against using #1 is all the sediment won't get out unless you repeat the process. With #2, if you let the water out too fast, it will agitate the sediment and it won't drain.

So which method is most effective?

The WH is a typical 30 gallon Whirlpool electric with a upper and lower electrodes. And yes, the water is BAD here. I plan on a softener and filtration whever life gets out of the way.

 

[panthera]

Jason,

How old is it? If it is already three years old or older and not yet flushed, you may do more harm than good.

I always drain first, then flush with clear water, and check the sacrificial anode.

 

[jasonl]

It's 2 years old this september.

 

[jasonl]

didn't think about the anode

Yeah, that should be checked too. How do you know if it's bad or not?

 

[panthera]

Jason,

The manufacturer will have technical details on what length/diameter is still acceptable, but it works perfectly until it is gone. If it's pitted badly and pretty eaten away, I'd replace it. Check out the link for pictures.
Two years is OK, but there is always the risk that the junk in the tank is what's holding it together...you should flush yearly.

I'd also check the bottom element for buildup.

Google Images

Google Images. The most comprehensive image search on the web.

images.google.com

 

[panthera]

bad link try this

sigh

http://www.gentleplumbing.com.au/2009/08/a-secret-to-double-the-life-of-your-hot-water-heater/

 

[yogitunes]

I flush mine every other month....just have a washer hose permanently hooked up to the floor drain....I leave everything on, and turn the valve on for a few minutes....also check the pressure relief valve to make sure it is functioning, also piped to the floor drain

the anode rod is sized according to the warranty of the heater, under normal usage, bad water may make it go faster, your mileage may vary, I had a 10 year tank replaced after 16 years of heavy use...3 Bathrooms and 6 TL washers...

but always a good idea to flush regularly....whats ever easier for you....but at least once a year you should turn off everything and do a total flush for safe measure....never hurts

 

[jeffg]

If you have a lot of sediment in the tank, you should do a complete flush:

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www.chilipepperapp.com

 

[sudsmaster]

In order to tell if the anode needs replacing, a little explanation is required. Most if not all sacrificial anodes are made with a wire running down the middle, and then either aluminum or magnesium (rarely, zinc) coating that. The ones I've seen are about 3/4" diameter. As a general rule, if less than 1/3 of the coating is left on the wire, then the anode needs replacing. Replacing it anyway is proabably a good idea if you have a replacement anode ready.

The most difficult part may be getting the anode out. Most of them have very large hex nuts on top of the water heater, and these can be very tight. I used an old 1/2" torque wrench (which I now use as a breaker bar) with a very large socket (something like 27mm) to unscrew the anode nut. Then you just pull the anode up and up and up. Some are flexible for tight spaces. Others are not, so make sure there's not a low ceiling over the water heater. Of course you'll want to disconnect power/shut off gas, turn off the water heater, and turn off the water supply valve before opening up the top of the water heater.

I don't understand how flushing a water heater could do more harm than good. If the water tank is being held together by sediment then it a ticking time bomb, and it's better to know when you are around to shut off the water/gas/electricity than have it happen in the middle of the night when you're asleep or when you are out of the home for an extended period. And a tank in such bad shape won't last long anyway, considering there is up to 60 lbs water pressure inside the tank.

It's also a good time to check the pressure release valve - making sure it works properly. These often lime up in time which in turn leads them to fail to activate, or if activated, fail to close properly. A leaking pressure release valve should be replaced. Also, the drain valve may get so much crud in it that it won't shut off. It should be replaced as well. And of course the tank should be drained for that job.

Prudence would dictate that before doing all of this, have a spare anode rod, a spare pressure release valve, and a spare drain valve at hand, or know that a nearby plumbing supply store has all three in stock and will be open if you need them. These are not very expensive items and much less than the cost of replacing the entire heater.

 

[fltcoils]

Water Heater Rescue

Google that, water heater rescue

a cool museum
links for anode rods
a cool energy efficient house.

You'll like it.

I have soft water, and it eats the anode rod about twice as fast.
My last heater died and I found the bottom weld had dissolved away. The especial cause, someone putting copper pipe in my 1927 galvanized pipe house. That action causes ALL the steel pipes to dissolve.

ouch.

Anyhow, replace the anode rod, be aware of the check ball flaw, be aware of the dip tube failure.

 

[cadman]

Some sound advice posted above-

If you've never flushed/drained your tank before, you may find the POS plastic drain valve will either refuse to reseat, or, worse, break off in your hand. I know of several engineers that have swapped over to brass ball valves as a matter of course.

 

[jasonl]

THANKS

Waterheaterrescue.com has a complete kit, anode, curved dip tube, and brass ball valve drain for $95. Looks like if I'm going to do the maintenance, just do the whole thing and get it done. Then next year, do just a flush.

I never realized all that could even happen in a water heater.

As far as soft water goes, I'd rather it eat anodes than ruin appliances (especially if vintage ones are connected).

 

[mayguy]

Ours is a GE 12 year model, and I flush it every other year. The water heater itself has a "self flushing" or whatever they call it, and does a good job keeping it clean.

When I flush ours, I turn the gas off first thing in the morning, Do our showers, and a load or two of wash till the hot water is gone.

Then I empty the tank out, once it's empty, I open the water valve to give it a quick burst of water to clean up the bottom..

 

[stevet]

Better late than never!

The first thing I do whenever I install a water heater of any size or means of heating is to take it out of the carton and take off the ridiculous drain valve the manufacturers put on them. Have you ever opened one up to drain a tank and the stem breaks off, the snap on washer falls off or the built up sediment is so great that water stops flowing? Have you ever been unable to stop the drips for the debris stuck on in the valve?

I remove the plastic POS and replace it with a 4-5" brass nipple and ball valve with a NPT-hose adapter to which I can attach a nice large diameter hose for draining.

In this manner, you will certainly get a larger volume of water to flow out of the tank and it will carry most of the sediment and debris out of the tank.

When it is empty, I will them turn the cold water on full force so it will flush the bottom some more.
I will repeat this a few times, it only uses a few gallons of water each time and stop when the water clears up.

A.O. Smith has some nifty kits available to "wash out" the bottom of the tank which can be easily fabricated by most of us. I have used the small, 1/4 " copper pipe attached to the end of a hose and a drain pan to get the last of the crap off the bottom and it works effectively as well. It can just be messy so use care!

I haven't replaced an anode yet but do have to try that soon. There are segmented ones available in case the ceiling ht is a problem.

This has all worked well for me and I have really never had a problem since I started installing a real drain valve.

BTW, I usually drain my tank once a month and no more than every 2 months. Our water is 7-10 gpg hard so excess lime buildup isn't a real problem.But why not be sure that the tank is clean, right especially on a gas fired unit?

 

[stevet]

One more piece of sage advice...

I was told once by a City Water Department supervisor back in NY that one of the best preventive measures you could add to your hot water heater is a fine screen line strainer or a sediment filter on the tank inlet line to keep large particles of dirt, sand and debris out of the tank.
Of course one step better would be a whole house sediment filter. That will protect all the appliance valves as well as keep debris to a minimum in your faucet strainers!

 

[tolivac]

When flushing your water heater or draining it otherwise for any maintenance BE SURE to turn off the power going to it-electric water heater elements should NEVER be allowed to run dry!This will burn them out in short order.Also its a good idea to shut off the water heater power if you are on vacation-not only to save power but to prevent hydrogen gas build up.An idling water heater still running but no water taken from it will build up flammable and explosive hydrogen gas.

 

[jasonl]

I just took a look at the WH today. The anode is up top. Aluminum and looks easy (enough) to get to. Remove the foam and unscrew it.

It does have the pitiful plastic drain valve, so I better have a new one handy dandy because it's gonna sure enough break.

Whoever was the idiot and used non-flexible PVC pipe for the inlet and outlet should be fired. Whoever designed the house with the WH where it is in such a SMALL closet with no drain connection for the T&P valve should be shot too.

But anyway, I'm going to find the brass valve that I need, flush the damn thing, change the valve and check the anode. If it has some anode left, I'll leave it and check it again next year.

I know basic plumbing and my bro-in-law is good at it so he can help me too.

 

[panthera]

Jason,

I'd immediately take a look at the furnace and all plumbing hook-ups if I were you, assuming the same idiots did them, too.

After two years, y'all are beginning to find out the difference between your excellent hand-work and the num-nuts you paid, no?

Three years ago, I was on-hand to watch the dum-asses install my partner's new water heater.

First, they wanted to take it up the stairs undrained.
Then, they wanted to re-use the one-shot flexible gas connection.
Then, they didn't want to screw down the exhaust, it 'ain't goin' noswhere'.
No dialectric (I was upstairs for five minutes on the phone) until I made a scene and, the hot water and cold water were reversed.

Not bad, all things considered.

I leveled it, reversed the hot and cold connections, soap-water tested the gas (it was leaking), and put in three screws to hold the exhaust hood in place on the vent, then another three to hold the vent (which slipped out of it's holder like it had just been lubed and was loose as a goose) in place and then made sure the chimney connection was packed tight.

They re-used the T/P rod, only because I insisted. They didn't even test it...

 

[jasonl]

Well

I'm not a plumber or electrician by any stretch, but I understand how they work and I know not to try to do something that I could get in trouble with.

That being said, I'm going to let it be and when my brother-in-law gets well enough (flu) he will help me do the drain so if something goes awry I'll have help.

When it's time to replace the WH I may go tankless or go 40 gallons and use copper/flexible piping. lumbers are nightmares and I'd be willing to learn it myself instead of having some idiot with an attitude do it.