Clean/flush tankless water heater???

[Muse]

I have a couple Ace #40003 submersible 1/6th HP water pumps to deal with a major puddle that forms right next to my house when I get moderate to heavy rain. Two, because one can fail, which I found out the hard way. Looking at reviews at Ace's website for my pumps I encountered the following, which makes me wonder if I should likewise flush out my tankless water heater:
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"This pump works great for flush/cleaning of my tankless hot water heater using 4 gallons of plain white vinegar that will clean out mineral deposits and gunk where the cleaning will improve efficiency of the water heater. Several videos are online demonstrating how to do this using a kit including such a pump, 2 washing machine hoses, and 4 gallons of vinegar. ACE had a much better selection of water pumps than 2 "big box" home improvement stores I visited and the prices were actually lower at my ACE hardware."
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I'm in Berkeley, CA. AFAIK, this area is NOT notorious for hard water, but maybe I should still flush my system. It's a Noritz Model N-069M-OD. It was installed in June 2006 and I can't remember doing any maintenance on it. I did a Google search and came up with some videos and watched one. The guy did like it says above, poured 3-4 gallons of white vinegar in a 5 gallon bucket and used a couple of washing machine hoses to cycle that vinegar through the heater continuously for 60-90 minutes. Should I do that?

 

[Greenman]

Couldn't hurt.

 

[Muse]

Couldn't hurt.

I figure. 12+ years. I'm not aware of an issue, but I don't use it all that much. Compared to most people I figure I'm using mine less than 1/3 of them. I should ask my neighbors if they think the water is "hard" here, or rather just how hard it is. I wonder if there's a way to analyze just how gunked up my heater is? And/or how hard the water is.

 

[NetWareHead]

I wonder if there's a way to analyze just how gunked up my heater is? And/or how hard the water is.

By analyzing the vinegar that is used after the descaling process. It will change colors from white to whatever depending on the mineral composition of the scale. You may even see whole broken off pieces of scaled int he vinegar. Another way is to judge the hot water quality before/after the descaling process.

 

[Muse]

The guy who fixed my plumbing issue yesterday (talented plumber!) says I should descale the tankless water heater every 2 years. He suggested Flow-Aide:

Amazon.com: J.C. Whitlam FLOW32 Flow-Aide System Descaler ,32 ounces (1 quart): Home Improvement

Buy J.C. Whitlam FLOW32 Flow-Aide System Descaler, 32 ounces (1 quart): All-Purpose Cleaners - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Sukhoi]

The guy who fixed my plumbing issue yesterday (talented plumber!) says I should descale the tankless water heater every 2 years. He suggested Flow-Aide:

Amazon.com: J.C. Whitlam FLOW32 Flow-Aide System Descaler ,32 ounces (1 quart): Home Improvement

Buy J.C. Whitlam FLOW32 Flow-Aide System Descaler, 32 ounces (1 quart): All-Purpose Cleaners - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

The reviews on that aren't great. It's apparently dilute HCl, and thus is pretty aggressive. You may want to stick with vinegar, which is a lot cheaper too.

 

[Muse]

The reviews on that aren't great. It's apparently dilute HCl, and thus is pretty aggressive. You may want to stick with vinegar, which is a lot cheaper too.

Interesting. Of course, I can buy gallons of vinegar at local supermarket (maybe Costco too), I hear you need 4. I have a gallon of HCL on hand that I bought for my kitchen tile repair job, which has been on hold since no hot water, but now I can get on it. I figure not to use it for the tile job. I could dilute it... hmmmm.

 

[Muse]

The reviews on that aren't great. It's apparently dilute HCl, and thus is pretty aggressive. You may want to stick with vinegar, which is a lot cheaper too.

Funny, the Amazon questions (I've read around 1/2 of the 40 or so questions) don't reveal this at all, but the Amazon customer reviews sure do! Thank you. I think I'll use vinegar and Noritz' instructions (the manufacturer of my tankless water heater), who do specify using vinegar. I had extra washing machine hoses but I think I put them out on the sidewalk as freebies a few years ago. Will see if my local public library tool lending library service has the hoses. If not, will buy a couple more.

 

[Muse]

Found a heavy duty extensive thread where the pros (plumbers, evidently) discuss the ins/outs/complexities, etc. of descaling tankless water heaters:

Flushing A Tankless

I am scheduled to flush a tankless on Monday, it has not been flushed since it was installed approximately 4 yrs ago. Because of this I've chosen to use muriatic acid. I do not have one of those neat little flush kits, I've put together my own, it consists of a 5 gal food grade bucket...

www.plumbingzone.com

 

[Sukhoi]

Interesting; maybe vinegar isn't enough after all.

 

[Muse]

Interesting; maybe vinegar isn't enough after all.

A poster down in the thread said that the Flow-Aide formulation was something other than HCL, but a phosphate solution. So, the info in the Amazon reviews may be incorrect.

There's no hurry, before I proceed I may contact Noritz for their input. I think they may have some informed pros I can talk to.

When I posted above that Noritz recommended vinegar, I think I was in error. I reviewed my data yesterday and I got the vinegar idea, evidently, from Youtube videos, not the manual for my TWH. I saw no info in it yesterday about descaling. I have to inspect it more closely, but yesterday I didn't see it.

 

[john3850]

When I repaired Dishwashers I used lime scale remover or muriatic acid to remove the hard water scale with only cold water.
Most hard water kits are cheap and most water has minerals in it.
I also had many problems with tankless hot water heaters not going past 115+ degree's.

 

[Muse]

When I repaired Dishwashers I used lime scale remover or muriatic acid to the remove hard water scale with only cold water.

I have a gallon of muriatic acid I got at Home Depot ~6 months ago. Don't have a use for it now. I'm worried that it would screw up something in the tankless water heater. Even the washing machine hoses used to cycle fluid through. I suppose I'd need to dilute it (i.e. pour it into water not water into it, I noticed that little bit of advice yesterday).

Yes, in the thread linked above it's said several times to turn off the device so the fluid going through is cold.

They said vinegar's only good for removing calcium scale.

 

[john3850]

The muriatic acid is great for stainless steel but may make holes in copper tubbing.

 

[waffleironhead]

I have very hard water and descale my tankless every year. I have the the isolation valve/cleaning ports installed, and use vinegar. Its a pretty simple process. Bucket, pump, washer hoses and a gallon of vinegar. Man the water is pretty nasty afterwards.

 

[MtnMan]

Glad I live where hard water isn't anything we have to deal with. Scale building up in plumbing, stain in tubs and sinks.

Our water supply is from a watershed in the mountains 15 miles away.