This Is How You Flush Your Navien Tankless Water Heater Properly

How to Flush Navien Tankless Water Heater, in these simple steps. Don’t have a tankless water heater? Or maybe you’d like one in your home? We can arrange that! Please call us today!

Watch our Video and You’ll Learn:

  • How Often You Flush Your Navien Tankless Water Heater.
  • How To Flush Navien Tankless Water Heaters Properly.
  • Find Out If It’s Okay To Use Detergent For Flushing A Navien Tankless Water Heaters.

Listen To The Audio

Enjoy this transcript below!

Troy: Hey everybody. Troy and Cole of Champion Plumbing out of Eagan. We’re going to show you how to flush a tankless water heater. Obviously we’ll do it for you, but if you want to save some money, it’s not that hard of a task.
We’ve got our Navien, it’s been installed up in the shop, Navien tankless water heater. This time we’re going to use, it’s called Haymaker. There are so many different kinds. You can also just use white vinegar and flush it through.

So what Cole is doing is getting set up. On the valves, they have the wash machine hookup on them. The hoses hook up. So he just turned off both the hot and the cold going into it. So now it’s completely isolated. He hooked the line in up to this, the line out up to this. Got a little pump in the bucket. Always read the directions if you’re getting stuff. If you’re using vinegar, I’d go what? Two gallons of vinegar probably.

Cole: Yeah. It’s more diluted than the actually descaling.

Troy: So we’re going to mix up the solution. This is a one to one solution. You put this in with a gallon of water, and it’s going to be easy. How often should they flush their tankless Cole?

Cole: I recommend once a year.

Troy: Okay.

Cole: Regardless of the status of, oh, I have great water or mine’s marginal water, just do it once a year. It’s the maintenance part. This is your heat exchanger that heats up and heats your water. When we flush it, it’s going to cruise through all of those fins and back down and just clean all that out so that burner stays good. Maintenance for warranty purposes. If this never gets maintenance ten years down the road it needs a new heat exchanger, they could potentially say we’re not going to warranty it because you didn’t do the maintenance call on it.

Troy: Yeah, that’s a great call. We warranty. If we put a new softener in like that BrassMaster we did with this one, we will absorb the 15 year labor warranty with the manufacturer warranty. So they have a 15 year manufacturer warranty on the heat exchanger. If we install a water softener with the install of a tankless, we will warranty the tankless parts and labor for 15 years. So you have nothing to worry about bumper to bumper. So he’s got the solution mixed up, one gallon of water, one jug of that. He’s got both his hoses. We’re going to make sure we unplug the machine or turn it off and open up those valves. Did you get it turned off already?

Cole: Yep.

Troy: Power?

Cole: Power’s not plugged in.

Troy: To the tankless so we don’t heat up our solution.

Cole: Nope.

Troy: There we go. So just pull the cord out quick. He’s got both things on and just dumping it right into the same bucket, pumping it through into the heat exchanger. It’s dumping it back out into the bucket. How long do we need to do this for?

Cole: 30 to 45 minutes. I mean, if you really see a lot of crud coming out and discoloring, I’d probably go a little longer, but if you’re going to do your maintenance once a year, that’s how long you really need to do it.

Troy: All right. Well, I’m going to chime off now and then we’ll get back on when we turn the pump off, because this literally just let it run. Let it run for 30, 45 minutes and we’ll show you how to shut it back down and fire it back up.
All right. So we’re back on. Been flushing her out. Now he is going to turn the pump off by unplugging it. You can see the solution. There is some crud in there. Not too bad though. We don’t use this for showering or anything. It’s just for training. So what’s the next step?

Cole: Well, I usually like to take the hoses off. Turn the cold and hot on and run the faucet without the tankless on for about five minutes. Just so if there’s any residual in here, we can kick it out of here.

Troy: Oh, so you’re kind of flushing out the solution.

Cole: Yeah. You could leave this one on, open the cold up and then let it shoot out of the hot side for a little bit if you wanted to. It’s the same difference if you just leave your faucet run. Don’t go around and open up all your faucets. Just go to your main one.

Troy: We always like to use a laundry tub faucet if you ever have one, because it doesn’t have flow restricters and stuff like that. Less of a problem. So you can see he’s closed the valve there. Got that valve closed. Both hoses are being disconnected. So you’re not going to flush that through?

Cole: No, I’ll just go through the faucet. If you don’t have a drain or something by you, you just got to let it run a little longer.

Troy: Notice he still hasn’t plugged the machine in. You want to give it a good flush before we turn it back on.

Cole: Going to pop this filter out quick too.

Troy: Yeah. This is important. This is a once a year gig with the Navien. It was just a quick pin you saw him pull.

Cole: If there’s any debris it will get caught in there. There’s nothing in there right now.

Troy: Let’s show them that clip. That was just a simple pull and popped out. So here he’ll put it back in.

Cole: Yeah. When put it back in, you got to be careful you don’t get that O ring off, because it will start to drip a little bit on you.

Troy: So just go in straight and smooth?

Cole: Yeah. You kind of might have to turn it a little bit.

Troy: Okay. Then you can see the two little holes, put the pin back in. That’s the filter. So you want to make sure you clean that every time you’re doing the flush of the tankless water heater.

Cole: Then we got one more that’s our incoming filter right here. This is any cold water coming into the unit. This is the screen filter for anything coming in.

Troy: So explain what the other one was. I thought this was the other one.

Cole: This is where the heat exchanger, any debris in here it’ll fall down and collect into here. This one is your cold water coming in, the screen so it protects any debris going into your unit.

Troy: Got it. And that one we can just do a backwards flush in the sink?

Cole: Yep. You can just take it off. Rinse it out. This one looks pretty clean. Obviously, this is a training purpose tankless so it doesn’t get used like a home.

Troy: That was just hand tight. No wrenches?

Cole: Yep. There’s just the O ring in there so you just get it snug and done.

Troy: So this entire process takes the only tool is the pump and two garden hoses, two small garden hoses.

Cole: I’m going to turn the cold and hot on, keep it unplugged still.

Troy: Again, the laundry tub is our favorite use.

Cole: Obviously open up the hot side. Just let it run for a few minutes.

Troy: All right. So flushing a tankless water heater, less than three minutes to do the steps, 30 to 45 minutes to complete the flush. How long should they flush this through now?

Cole: I’d probably go five minutes.

Troy: Just a quick five minutes.

Cole: Then you know you’re getting all that fresh water in the system and kick back out of it through the lines down on here, then you can shut it off, plug it back in.

Troy: There we go. So once you plug it in it will fire up all by itself. If you Have a tankless water heater, you need it flushed, you can obviously follow the steps on this video or give us a call 651-365-1340. Look us up on the web, and as always, please click the like and the subscribe button. Anything else?

Cole: That should be it. Thanks for watching.

Troy: Thanks for watching.

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We work Monday through Friday: 7:00 AM – 5:00 PM and Saturday: 7:00 AM – 12:00 PM. After hours emergency service is available. You can find us at 3670 Dodd Road in Eagan, MN 55123 during our open hours. You can also call us at (651) 365-1340 or email us.