Guide on How to Flush a Rinnai R53i Tankless Water Heater with Vinegar

Going to show you how to flush Rinnai R53 tankless water heater. Need a few items here need a bucket. Three gallons of Vinegar is what I use. Get the white distilled vinegar. And I use a quarter horse utility pump. It does real well for me.

I think you can use like an eighth horse pump. I prefer a little more power of course you need a set of appliance hoses, washing machine hoses and get the one with a 90-degree end on it. Okay, so I’ve shut off my water supply now I need to drain the water out of the water heater. What I’ll do is turn off this valve this valve here that will cut off the incoming and outgoing water from the water heater and I’ll take these caps off and open up these two valves. That will course drain the water out. And then allow the vinegar to pump through the water heater and back out into the bucket. Now before we get started we’re going to unplug the water heater. And of course turn the gas off right back here. And let’s get started. Okay, so now I connect my hoses. Take the hose coming from the pump, hook it to the cold side. Probably doesn’t matter which way you do this, but this is what I prefer. Okay, take your other hose, hook it to the hot side. Alright, those are pretty tight. Now, let’s put some vinegar in a bucket. Dump in all three gallons of vinegar. Now we’ll go ahead and set our pump inside the bucket of vinegar let it sit down on the bottom and Put the other end of the other hose in the bucket as well. Okay, now before we get started pumping there’s one other thing I like to do. There’s a filter inside here I like to take that filter out. It allows the vinegar to run through the water heater. A little better, and I’ve also got a new filter to put in anyway, so I’m going to take that out of there. Just remove the cap take the filter off put the cap back on and we’ll be good to go. So let’s take this filter out. Okay, so there’s the filter Pop that off of that black cap there and put the black cap back on. Alright, so here’s the black cap without the filter. Just screw that back in there tighten it up so it doesn’t leak we’ll start pumping.

Okay, we’re in good shape. Let’s get this pump plugged in Vinegar is flowing through. So let that pump I usually let that pump for about 30-40 minutes. Maybe even an hour sometimes. Depending on what I get busy doing so we’ll come back and check on it here in a little bit. Okay, so it’s been about 40 minutes. The vinegar turns blue.

This is a chemical reaction from the copper pipes. I’m going to unplug this pump, Lift the pump up out of the vinegar to let it drain out of the water heater. That’s pretty good. Set that aside I’ll take this and use it as a as a weed killer probably make some salt with it and spray it on some poison ivy, and crabgrass rinse this bucket out and put about that much water into it and then flush the vinegar out out of the water heater. Then get it all put back together, turn on the water, the gas, plug it in and we’re good to go okay, so I put some fresh water in this bucket and put my pump back into that waterand the end of the other hose. Plug it back in let that water run through for a minute. That’s probably good enough same thing, let that drain out, Set that off to the side. All right now I’m going to go and empty this water out, and start putting everything back together be right back. All right, so take our hoses off. And close these valves. Put our caps back on snug those up. All right, so we gotta change that filter out I already took the old one out.

All right, so we have a new cap, new o-ring, new filter. So let’s put that in That’s that Alright, got her plugged back in, got the gas on, I just turned the water on. Let the water flow back through and we’re all done.