This goes into maintaining a tankless water heater. What we're going to talk about today is the basics that you really need to maintain the system. This systems, it's very very important because they have such small tubing in them, that you maintain them at least once a year. To do that, what you need to do is be able to run white vinegar through the system to clean it out from all the calcium deposits. It keeps the heat exchanger inside clean, and keeps things going. Also, you'd want a certified guy to come in and check on gas pressures and make sure it's burning clean, i.e. carbon monoxide, to keep it from being harmful. This one being outside, it's not so critical, but it really does help to maintain the gas burning of the system because it could end up with hot spots and that can wear your heat exchanger out. So basically what we do here, is we have a little pump set up, something that you can pickup at Home Depot or any place. They're a little bit expensive, but it's something you need to maintain one of these things. And if this is something that seems like it's above you, or anything along those lines, you need to call a certified guy to come in a do it, which is what I'd recommend anyway with these tankless water heaters. Now, I'm doing this as a demo without these valves installed because these were to be installed on this system and they're not on this system. But I have some so that we can go through what we've got to do. So you take... you have a five gallon bucket. You take one end of it. You can use a suction pickup like what I have here that'll pick the vinegar up out of the water. You dump that into the bottom of the water. Make sure that that's down to where you've got flow. You just take regular white vinegar that you pick up at any store and you fill it up in your bucket. Give it, oh, three or four inches over the thing, over the top of your suction, just so you've got plenty in there to clean out 'cause you'll be surprised actually what you'll pull out of the tankless itself. So you hook your hose into the inlet on that, and then the outlet hose, which is a basic standard washing machine hose, goes to your valve that goes into the cold side of the tankless water heater. As you can see the blue indicator here indicates the cold side, so it makes it visually also, you know, pretty simple to pick out which is which. Now the next thing that you want to do is make sure that the water is shut off to the unit itself. You do that by turning this valve. That was actually in the on position. This is the off position when it's ninety degrees. When it's this way, it means that the water is going to pump through and up and in to the unit and then back out. That's what you want. Now, also, with this valve here can close and open. With this valve closed, you're not going to pump anything through, so basically it completely isolates what you're doing right now. No water can come in or out of the system. A lot of these pumps need to be primed. What priming means is they need to have water put into them before you turn them on. So what you have to do is leave this cracked, leave this cracked wide open and go ahead and run some water back in until you see water bubbles going out into your barrel there. Once you see that, go ahead and shut the water off, and then it's ready and primed ready to pump. So this, this is set up over here. We'll just set that on the cold water side. This is on your hot water side coming out. In this valve you do the same thing, shut it to the off position which means it's shut the water off, isolated it from the house and it's coming up right here. And with this valve in the on position as it is now. As you can see it goes off as well. When it's ninety degrees from your pipe direction, those valves are off. When it's in line with the pipe, the valve is on. Now you're ready to begin pumping. What you do is you stick this outlet in, back in to your bucket. So you have two hoses coming out of your bucket. One of them is going into your pump, and out to your cold water side. And one of them is coming out of your hot water side going back into the bucket. And then what you do is simply plug the pump in and let it do its thing 'cause what it does naturally now is pump the vinegar through there and cleans it out in one of the most natural forms that you can with white vinegar, so it's really not harmful to your system. Now you let that run for about ten to fifteen minutes until you kind of see clear gunk. If you want to change out the fluid, you know vinegar's not that expensive to where you can see that you're actually getting clean out of it, then you're good to go, but typically if you just let it run about ten minutes, you've done the job that it needs to be. And then you of course reverse the process. Here's your hot. You basically make sure your side waters are off. You shut this valve off. You disconnect your hose. And then that'll sit there like that. Some of these have little hose covers. You put that on there just to cover it up from any leaks. Then you do the cold. You don't turn the side valves on until you have everything done. And the first one you turn on is the cold. So you do the same thing over here. Your pump is off. You shut your inlet valve. You disconnect it. You put your little hose cap back on. Now you're good to go ahead and turn your water on. You need to make sure that the power is off to the unit or it is unplugged or disconnected. You do that before you do anything. Power is very important. If you do not disconnect the power in the unit, you can harm yourself or you can harm the unit itself. So it's very important that you shut the power off before you do anything. Now, you go ahead and turn the water on before you turn the power back on to it or plug it back in, and you let the system flush into your sink or wherever. You can let it flush, and it flushes out the vinegar is what it does. Both the hot valve, or cold valve in the on position and the hot valve in the on position. And then you go inside and turn the tap on and it lets it flow out. And typically you can smell when it's done running the vinegar through. Then you go ahead and fire it up and you may notice a little distinct vinegar smell for a little while longer, but it won't be there long because it'll cook it out when it fires the unit back up fire wise.