Descaling needed with softened water?

[Lifespeed]

I have only used my Noritz NRC1111 with a backwashing carbon filter and water softener. I thought I read that descaling wasn't required with soft water.

Anybody run a tankless and water softener together long-term without issues?

 

[Killer95Stang]

Did you install service stops? Even though I have a water softener that feeds my Rheem tankless, I still make it a habit of descaling about about every 6-9 months. I use two washing machine hoses, a small pump from harbor freight, some vinegar and a 5 gallon bucket. Let it run for 45 minutes and flush it with clean water. Never had an issue, but I've only had my system since 2013.

My friend from work who has been using his tankless with an undersized gas line, no water softener and a puzzled look when I asked about descaling ,has never had an issue in the five years he's had one. Go figure.

 

[Sponsor]

 

[Lifespeed]

I did it all correct with 1" gas hard pipe right up to the unit as well as flush valves. It has been in there for three years and hasn't been flushed. I suppose I should do it, but kind of a PITA not to mention $80 worth of hardware. And it may well not need it . . .

 

[Master Plumber Mark]

It will work fine without de-scaleing the unit ....until it finally gives out sometime in the next few years....

Of course it voids the warranty

 

[Lifespeed]

Gives out from what? There is no Ca++ or Mg++ in the water.

 

[Master Plumber Mark]

If you read the very fine print with all these dogs, somewhere you will find that they state
that the warranty on the unit will be Voided if the unit is not "periodically " de-limed....
You can argue with them till you are blue in the face but they expect this maintenance to be done
even in pristine water ....they will not send you out another unit or warranty it...

we have a bunch of them in town that were never serviced since they were installed and eventually
after 3 years or more they finally just seize up ....
It normally cost about 250- 300 bucks to have someone come out and de-lime the units once a year.

they are simply a pain in the ass and unless you de-lime them yourself they will not save
you a dime over a normal tank type water heater.....

thank you

 

[Killer95Stang]

This is a good example of the setup I use to flush my tankless with vinegar. I also use this Rheem technical service bulletin as my guide to service my Rheem unit. http://hometips.me/Tls/Rheem-De-lime-tankless.pdf

This is pretty much as simple as plumbing (if you can call it that) gets. If you can change oil then I would consider this to be an easier job. A few dollars worth of white vinegar, a cheap pump from Harbor freight, bucket from home-cheapo and some washing machine hoses. Takes less than an hour, and doesn't require that you babysit the it while its doing its job.

Seriously, no disrespect to real plumbers, but I imagine that you guys consider this job as interesting as putting air in tires for mechanics.

Also, in my situation the tankless unit freed up a lot of space over having a traditional large 50 gallon tank . With that added space I installed a water softener and R/O system within the same footprint. I also enjoy long showers without fluctuations in water temp. When family stays over, we take shower after shower without anyone being left out in the cold. Not to mention, my previously normal $25 - $40 gas bill dropped to $10 - $20 per month... with a couple bills being about $8.00. I think overall for me, the positives outweigh the negatives.

 

[Master Plumber Mark]

you are doing ok if you can de-lime the heater yourself and will probably save some money
but if you are not willing to get your hands dirty and fool with the vinegar and pumps about 2 times a year then you are gonna lose money calling a plumber out to do this task for you....

One big company in town charged 300 bucks to come out and perform this task.. of course they provide the vinegar for free....

I dont do this job because usually if the error codes are going off and it dont work right after you have de-limed it
for a over an hour ....
then for some strange reason they expect you to get the
unit running right for them just because you are there which might be impossible to do.....

and you can get accused of somehow damaging the unit....
so we dont touch them

 

[Lifespeed]

Flushed it with vinegar tonight. $70 for the equipment. The 1/6 HP Harbor Freight submersible pump was pretty impressive at 23 gallons/minute. No, it wasn't hard to do.

I agree with Stang about the benefits of tankless, including the space savings. I also put my water treatment where the tank heater was in the garage. The tankless is in the attic above the two bathrooms.

Got some fine black grit out, but I did not see any chunks of lime scale. Copper pipes, softener, and carbon filter are only three years old so I didn't expect to find much.

 

[Jadnashua]

You'd only see chunks of scale if they became dislodged before they were dissolved. The acid in the vinegar dissolves the deposits, so you will not generally see much of anything except non-soluble debris (like maybe those black specs from the carbon filter).

 

[Lifespeed]

You'd only see chunks of scale if they became dislodged before they were dissolved. The acid in the vinegar dissolves the deposits, so you will not generally see much of anything except non-soluble debris (like maybe those black specs from the carbon filter).

Yes, it dissolves but I have seen plenty of pictures and comments on the internet about particles of scale coming out of tankless operated with hard water. And I still question where the scale is going to come from given my softened water does not have the calcium ions to form scale.

I guess de-scaling isn't going to hurt even if it may not be needed.

 

[Killer95Stang]

Seems like Mark The Plumber really hates Tankless water heaters. Has the carb vs. fuel injection battle in full swing.