Flushing A Hot Water Heater

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Flushing A Hot Water Heater

How To Flush A Hot Water Heater To Remove Sediment


Hey everybody. Today we’re going to talk about how to drain a hot water heater.

And this is really important to do about once a year because sediment can build up inside your hot water heater, and it kind of collects all down at the bottom of the tank and eventually turns into this big deposit that’s turns into like a solid concrete mass at the bottom of your tank.

This reduces the efficiency of your tank and can actually shorten the life of the tank because that deposit is very corrosive and it can actually eat right through the metal of the tank, and before you know it your tank starts leaking and it’s an emergency middle of the night replacing a hot water heater situation. So by draining the tank about once a year you can stir up all that sediment and flush it out so that it doesn’t collect in the bottom of your tank and cause you problems down the road.

It’s a pretty simple process, so let me show you how to do it.

So the very, very first thing that we want to do is turn off our heat source.

This applies for both gas and electric. I’ll show you on how to do it for gas because that’s what I have here.

If it’s electric, then you should just go find the breaker where your hot water heater is plugged in and flip that breaker or simply unplug the hot water heater from the wall.

For a gas one though, the simplest thing to do is just to change your temperature setting all the way down to either pilot or vacation mode if yours has one like that.

This will prevent the burner from turning on as we’re flushing the tank with the cold water and if you forget to do this, you have a very real possibility of completely ruining your tank, because that burner will turn on and try and heat up an empty tank which can actually melt the metal and cause your tank to fail. So, very, very important first step: turn off your heat.

Alright, now that our heat source has been disabled, the next step is to locate your cold water supply valve for your hot water heater and turn it to the off position. Mine happens to be up on top of my tank and it’s just a simple ball valve that you rotate just like that.

Now the next step is to connect a garden hose to the drain spigot at the bottom of your hot water heater. You want to put it on nice and snug, but don’t over tighten it as you can damage the threads.

So now we’re almost ready to drain the hot water, but there’s one last thing we have to do.

If we were to open this valve now, since there’s no water being allowed into the tank anymore, it would act like a straw with your finger over the end of it and no water would flow out. So we need to allow some air to get into the system. To do that, we just open up a faucet anywhere in the house on the hot water side only. This will allow air to travel in from the faucet side so that the water can drain out of your tank.

Okay, with our cold water supply turned off and a faucet opened so that we can let air into the system we’re ready to open up this valve.

On my particular hot water heater this valve is the kind that only takes a quarter turn so that the valve gets in line with the drain pipe. Now, when you open these valves if you don’t hear any water flowing or any air being sucked into the system then you might have a backflow preventer valve installed somewhere in your plumbing, and as a result, opening a faucet is not enough to be able to let air into the system so that this can drain properly.

So instead of a faucet open we’re going to use a pressure relief valve to allow the air to get into the tank. Now, you want to be careful with these because they are an important safety feature of your hot water heater.

These are here because if the pressure inside your tank ever gets large enough that the tank might possible explode, then this relief valve will open up and let all that extra steam and hot water out so that your tank doesn’t explode. You shouldn’t play with these too often or too much and you want to make sure it gets seated correctly when you’re done with this job. But to open it is very simple, you just grab this little arm right here and bend it straight up.

Then you’ll immediately hear the air is getting into the tank and the water is flowing out the bottom.

So while the water is draining it’s a good idea to come and inspect what’s coming out of your tank. In my case the tank has only been installed for a little less than two years.

This is the first time it’s been flushed and the water that’s coming out is quite clear. This will take quite some time to drain – be patient and wait until the entire tank is empty. One quick word of caution: this water is hot. Don’t let kids or dogs or friends or anybody come and play in it while it’s draining. Just let it drain out into the street. Don’t put it on your flowers.

Don’t put it on your garden. This is scalding and it can damage things or hurt somebody, so be careful.

Alright, so it has been draining for about fifteen or twenty minutes and the tank is basically empty at this point.

But the drain is such a gentle process. It doesn’t really agitate any of that sediment at the bottom of the tank. So before I’m completely finished I’m going to do a couple of things. I’m first going to open up the cold water inlet for about fifteen or twenty seconds which is going to spray a whole bunch of cold water down to the bottom of the tank and agitate whatever’s down there.

I’m then going to let it rest for fifteen, twenty seconds, let some of that drain out, and then I’m going to repeat that process three or four times.

You can see, maybe it’s a little difficult to see, but there is some particulate that is coming out with this water that’s draining out of the hose now that I’ve done that one flush. So I went and grabbed a bucket so that we can see some of this sediment a little bit better. This is a clean bucket and you can see there’s little flecks in there, in the water that we’re kind of swirling around.

These are all coming directly off the bottom of my hot water heater tank. That’s the stuff you’re trying to get out of your tank and that’s what’s built up over the last year and a half of us living in this house. Yeah there’s still definitely sediment coming out of the tank so we’ll keep flushing until we get a bucket that’s clear.

Alright so I’ve flushed it four times now that way and let’s see how our water looks now. That looks very clear.

There is one little visible speck floating around in there. But it’s significantly better than it has been. Alright so we’re done with the agitating kind of flushes and we’re ready to move onto the next step.

Alright, so at this point the tank is pretty clean. There is very little particulate still coming out and most folks at this point would just fill the tank back up, turn off all the valves and business at usual. There’s one more step that I’m going to take just to make sure it’s as clean as I possibly can get it, and that’s is I’m going to fill the tank completely back up with cold water and drain it one more time.

By filling it back up completely I’m going to agitate even more of that water that’s at the bottom of the tank and that’s the whole point of this exercise: to try and scrub out the bottom of that tank as well as I possibly can. So I’m going to fill it all the way back up one more time, drain it all the way one more time, and then fill it back up for regular use.

So to fill it all the way back up, I open up the valve on the top of the heater, and then I’m also going to close the valve on the drain hose and I’m going to close my pressure relief valve just like that. Alright, I don’t hear anything flowing anymore into the tank so as soon as you think it’s full open that valve back up at the bottom and close the valve at the top.

And then we’ve got another twenty minute wait while this drains again.

Alright, so my bucket looks pretty clean. Let’s go ahead and check to see how this water coming out now looks. This is after a complete refill of the tank. I see a few small specks in there but it’s really not bad. So I’ll let this tank completely finish draining and then I’ll close the hot water heater back up and refill it completely.

Alright, so my tank is now completely empty and I’m going to close the drain valve and I can remove the hose. Next I can open the cold water inlet one more time and that will start to fill the tank. Now I’ve still got my pressure relief valve open because as the tank fills all that air that’s in there now needs to go somewhere and I’d rather it go out the pressure relief valve than into my plumbing.

Now, you do need to use a little bit of caution here because if you just leave the valve open and fill up your tank the water level will come up to the height of that valve and come right back out that pipe and down all over your floor.

So I’m not going to leave it open for very long. I’m going to stand here and I’m going to listen and as I can tell that the tank gets closer and closer to full I can go ahead and close this relief valve and then I’ll have very little air in my tank.

Okay the sound has changed a little bit, I no longer hear the water trickling all the way down to the bottom of the tank. It is filled somewhere better than halfway. I’m not going to risk it, I’m going to go ahead and close this pressure relief valve now so that no water comes out down the bottom.

Alright, with the pressure relief valve closed again now I can set my thermostat back to my desired temperature. The burner will turn back on underneath the tank and I’m done.

And finally the last step is to open the hot water valve on any faucet in the house to make sure all of the air gets bled out of the system. Once the water is flowing normally again you can shut it off and you’re finished.

Alright, so that’s it. It’s not a very difficult job to complete but it is an important job that you do need to do to extend the life of your hot water heater. Flushing it out about once a year is all it really takes to keep that sediment from building up and ruining your tank and making you run into an emergency at some point down the road when your tank finally fails.

So flush it once a year and your hot water heater will give you plenty of hot water for many, many years.

That’s it for this one, I hope you’ve enjoyed what you’ve seen. I hope you’ve learned a little something. If you did, go ahead and hit that subscribe button down wherever it is and as always, thank you very much for watching.

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