Idea to remove scale from hot water line in house

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themarkg

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I want to attempt something to get rid of scale in my hot water line
in my house. I need your advise to make sure I'm not going to damage
the existing plumbing. First let me explain the problem, then I'll
explain what I'd like to do. I'm out of ideas and really need help as
this is driving me nuts! Sorry for the long post but I need to give
you the background.


BACKGROUND

My double story house built in 1995 and there were 2 x 50G gas hot
water heaters upstairs in the attic above the master bedroom.

When I purchase the house in 2010 the owner replaced the original hot
water tanks with a fancy 50G A.O.Smith Vertex high efficiency gas
water heater. That single tank provided enough hot water for the
whole house!

After being in the house about a year (so maybe tank was 1.5 years
old) I started noticing particles coming through the hot water line in
the kitchen. I'm 99% sure the particles are calcium build-up (scale) as
vinegar seems to soften them. Also the dip tube on the A.O.Smith tank
was blue PVC, not white. I used to flush the tank frequently which
helped but didn't solve the issue. I got so fed up with particles
blocking faucet screens that I replaced the high efficiency tank with
two 50G Rheem conventional water heaters two years ago. I'm sure the
super fast heating was producing precipitates. Tank was 80K BTU insead
of the typical 36-40K.

I had the plumber connect one of the new tanks to the master and guest
bath, and the other tank to the bathroom upstairs and then, downstairs
to the utility room and kitchen.

After installing the new tanks I still noticed the particles in the
kitchen sink faucet. I waited figuring this would clear itself out of
the pipe. It didn't. So this lead me to think the scale is in the hot
water pipes themselves since the tanks were new. So I tried one last
thing. I installed a 3M Aqua-Pure Scale Inhibitor (AP430ss) which a
buddy of mine told me about. The unit fits on cold water inlet going
into the hot water tank that feeds the kitchen. The fitting takes a
replaceable cartridge with "food-grade" acid and is supposed to
disolve the buildup in the pipes. It's been on for 2 years now but I
still get particles blocking the sink faucet.

In the past winter, water flowing out of the sink faucet has got so
slow that I've had to remove the faucet head and wash it out 3 times
while washing dishes. It's always worse first thing in the morning,
which has to be due the scale in the cold pipes expanding as the hot
water flows over it.

This summer I hardly notice any scale. I was thinking the 3M scale
inhibitor was finally working, but as it has started to cool down at
night, the scale has started reappearing.


I have one idea short of ripping open walls and replacing the hot
water line to the utility room and kitchen,



MY LAST IDEA (and I need your advice here)

I had an idea of creating a recirculating loop in the hot water line
and running vinegar through it. I'm sure this will help.

To do this I'd connect a short hose from the washer hot water outlet
in the utility room and run that into bucket. The bucked would have a
submersible pump with a 100' garden hose attached. The hose would run
to the hot water sink value in the upstairs bathroom. This would
create a recirculating the loop and I'd simply pour vinegar into the
bucket and let the pump run for a while.

What I need to know is what size pump I should use. I don't want to
connect something and damage the plumbing. I think there's a 12'
difference in height between the washer downstairs and since faucet
value upstairs.

Also, would it be better to have the pump downstairs and "push"
vinegar upstairs to the 3/8" sink facucet value fitting, or, have the
pump upstairs feeding directly into the faucet value and "push" the
vinegar from upstairs, through the copper line downstairs, then
through the hose upstairs?



Couple of things I should mention:
0) my neighbours don't have hot water issues
1) the sink fixtures attached to the other new tank don't have any scale
issues
2) I've turn down the water temp which should limit new scale buildup
3) there is PEX pipe running from the new hot water tank across from one
side the house to the other, and then connects to the original copper
pipes that feeds the upstairs bathroom and the goes down to the utility
room and kitchen. Can the PEX to copper connections be causing
scale? The PEX was apparently added when the Vertex heater was
installed.
 
Are you on well or municipal? Do you have any idea of your water hardness (calcium and manganese)?

The 3M™ Whole House Scale Inhibition Water Treatment System AP430SS contains polyphosphates to bind calcium and magnesium hardness minerals, preventing them from precipitating out (or becoming a solid) and building up on metallic surfaces such as water heaters and plumbing fixtures like faucets, pipes and shower heads.

The above relies on the Water Conditioner (Salt-less Water Softener) which only works in low grade impurity levels. If you have a high level of hardness, a true water softener is the only way to prevent scaling and blockage.

-Saltless Water Softeners: Fact or Fiction?-
 
KULTULZ, thanks for the response. I'm on city water. No idea about hardness level. It's definitely a little hard. But I have no issues at all with cold water. Also it's just one of the two hot water tanks.I'm convinced it was the A.O. Smith Vertex hot water tank that accelerated scale production in the pipes.
 
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Heating the water causes calcium to fall out of suspension.

You can buy water test kits to measure your level(s) of hardness. The actual calcium is too small to filter before or after the WH. It has to be treated with a softener (ion exchange).

About all you can do now, is add vinegar to the WH, let it sit and then flush. This will have to be done frequently as if the calcium (and possibly sediments) are allowed to collect may hinder proper operation and the ability to drain/flush). Once the calcium sticks (coats) the tank and components inside, it is usually too late.

Clean-out-gas-water-heater-350.jpg

Gas WH Thumping.gif
 
:(

I have been ciphering on this...

The 3M Aqua-Pure AP430SS system installs BEFORE the hot water heater in order to filter the water before it reaches the hot water heater. This helps prevent damage to the hot water heater from scale buildup. The 3M Aqua-Pure AP430 Hot Water Filter System comes with the AP431 water filter cartridge and the 3/4-inch inlet and outlet water pipe connector. The 3M Aqua-Pure AP430 hot water filter system installs directly on the 3/4-inch pipe leading into your hot water heater. The AP430SS will extend the life of your hot water heater or tankless hot water system by stopping scale buildup and corrosion, and helps save money on maintenance costs. Features a stainless steel fitting and a consistent dose of Siliphos. Siliphos is a 100% pure food grade scale inhibitor approved by the USDA.

The AP430 filter system binds calcium and magnesium hardness minerals, preventing them from precipitating out of solution and building up on metallic surfaces which helps prevent piping systems from corrosion and inhibits scale buildup in hot water heaters & water-using appliances.

You were experiencing this sale build-up before this installation. It may be that the filter (conditioner) is adequate but the WH was full of dissolved calcium and the filter (conditioner) would not make a significant difference in this situation.

Have you ever drained and flushed the tank? The hardness precipitated out of suspension during the heating process and has settled on the tank's bottom. It is regularly agitated by cold water introduction via the dip tube and goes back into suspension. It (tank) has to be drained and flushed and start with a clean slate.

An actual water softener install brings on a new set of problems. These conditioners are recommended for tank-less units as well as tank units. You can buy different capacity conditioners.

I tried a conditioner system on my home and it had no effect. Of course I have extremely hard water (well) and they are recommended for usage up to a certain amount of hardness which they didn't bother to tell me.

Sediment Buildup _2.gif
 
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So I tried one last thing. I installed a 3M Aqua-Pure Scale Inhibitor (AP430ss) which abuddy of mine told me about. The unit fits on cold water inlet going into the hot water tank that feeds the kitchen. The fitting takes a
replaceable cartridge with "food-grade" acid and is supposed to disolve the buildup in the pipes.

It's been on for 2 years now but I still get particles blocking the sink faucet.

Wondering... Have you ever replaced the element in the water conditioner over the two years? The substance does deplete.
 
KULTULZ, the 3M T has a cartridge which I replace every 6 months. It's on the cold water inlet into the tank. As for flushing, the tank is about 2 years old now and I flushed it today for the first time. The scale particles are in the lines because I replaced the tanks and still had particles clogging my faucets.

Today I made a recirculating loop with a 1/6HP submersible pump and two garden hoses. With the arrangement I was able to keep the bucket on my patio and ran the hose from the pump in the bucket to the hot water outlet hose on my tank, and a hose from my washer valve into the bucket. I recirculated 6G of vinegar in my hot water line (not in my tank) for 3 hours. The pics below show the setup. I was quite amazed at the size of the chunks. I need to do this once more and I plan to do it and let the vinegar recirculate overnight. Also I want to use a 1/4 HP pump to get the flow a little faster.

The first picture is my washing machine hot water inlet after I pulled off the hose hose today. I cleaned it in last in Apr. As you can see I have a problem!

I'd like to use the a tankless cleaner but 6G is pretty cost prohibitive. It would work much faster than vinegar.

IMG_3126.JPG

IMG_3128.JPG

IMG_3136.JPG

IMG_3134.JPG
 
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As for flushing, the tank is about 2 years old now and I flushed it today for the first time. The scale particles are in the lines because I replaced the tanks and still had particles clogging my faucets.

It may be that the calcium deposits (particulates) on the bottom of the tank have become too large to be able to flush.

Do you have the original drain valve or have installed a full bore ball valve for drainage?

Can you show a photo of the WH(s) installation? I would like to see how he split the supply side to both. Allowing a vinegar mixture to sit in the tank for twenty-four hours and then flushing the house may help also. Remove all faucet aerators when flushing the lines.

What is puzzling is that you have excess calcium and the neighbors don't... :confused:

Sediment Draining _2.jpg

Sediment Draining _3 Flushing (Reverse Pressure).jpg.jpg
 
Kultulz, went into a plumbing store today and came out with 2 gallons of Flow-Aid descaler and a hole in my wallet. They mix 4+1 so I'll have plenty to use. VInegar worked but takes a long time and didn't get it all.

The buildup I flushed out of my pipe turns white when it dries. The stuff from the tank in your picture looks like sediment.

I'm 99% sure my problem is in the pipes as I still had the same issues when I installed the new tanks. Also, my second tank (same tank) has no issues feeding section of the house it supplies. Thanks G-d I decided to keep the tanks seperate instead of connecting them together.
 
Forgot,to answer your question. When the plumber installed the two tans, I had him relace the drain values with ball valves.
 
I know I'm posting in an old thread here. But there is some misinformation here I want to point out to anyone reading: Siliphos (used in the Aqua Pure scale inhibitor cartridge mentioned above) does NOT remove, soften or dissolve existing scale. It stops new scale from "sticking" so easily.

You can write 3M and ask them like I did. 3M did say that, over time, a whole house water softener will remove some scale from inside pipes. So that really is the very best solution if you can do it.

I couldn't add a whole house softener to my house without it being a major renovation project and costing me an arm and a leg. So I added the Aqua Pure scale inhibitor to cold feed on my 10 yo tankless (Rinnai) instead. I have moderately hard city water and had been descaling every six months since it was new. I change the cartridge every six months. It has cut my descaling routine from every six months to every two years. I could probably go longer but two years is so easy by comparison. I see far less visible scale collecting in tub and shower, faucets, sinks, washing machine, dishwasher, etc. It is a good compromise.
 
I know I'm posting in an old thread here. But there is some misinformation here I want to point out to anyone reading: Siliphos (used in the Aqua Pure scale inhibitor cartridge mentioned above) does NOT remove, soften or dissolve existing scale. It stops new scale from "sticking" so easily.

You can write 3M and ask them like I did. 3M did say that, over time, a whole house water softener will remove some scale from inside pipes. So that really is the very best solution if you can do it.

I couldn't add a whole house softener to my house without it being a major renovation project and costing me an arm and a leg. So I added the Aqua Pure scale inhibitor to cold feed on my 10 yo tankless (Rinnai) instead. I have moderately hard city water and had been descaling every six months since it was new. I change the cartridge every six months. It has cut my descaling routine from every six months to every two years. I could probably go longer but two years is so easy by comparison. I see far less visible scale collecting in tub and shower, faucets, sinks, washing machine, dishwasher, etc. It is a good compromise.
 
I replaced my water softener headache with a Pelican (now part of Pentair) water conditioner. Ar about three months of the conditioner's installation, the shower head and aerators had to be cleaned from the scale from the lines.
 

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