Extreme calcium buildup In hot water pipes

[SK Sharma]

Hello everyone. New Post here. Thought I would throw this out there to acquire advice. Our house is fairly new construction, just over five years old in the Westlake Hills area. The water service company is Aqua out of the Rivercrest water system.
My system is a two water heater, gas furnace, 60 gallon AO Smith commercial with a hot water recirculating loop tied in with a timer by TACO. We never had shut the circulating a loop off in the 5 1/2 years that we’ve been in this house. And has been running continuously during that time. (I know: in hindsight big mistake.)

We have been having slow flow of water in the fixtures and build up of scale throughout the house increasingly for the past six months, having called in handyman every now and then to help troubleshoot the fixture valves and or aerators in the house.

In the end, the water became a trickle mostly on the hot water side, to which I eventually got a water mineral test or hardness test. One company came in and said it was 12 grain/gal which I thought sounded awfully high for this area. Got a second opinion that rated the hardness around 6-7. As a side note, I had only flushed the hot water heaters (both of them) once, last year for the first time which seem to help for a little while.

So I purchased a water softener system 2 weeks ago—I can give the details if you want—but it’s from a local company here that has a pretty good reputation, and they also flushed and drained both water heaters at the time. The comment that they made was that there’s too much buildup in the water heaters and could only do so much given a limited time they had and the small outflow valve of the water heaters.

I had another company come out today and for the first hour and a half and they continued to see constant large calcium/mineral chunks and the conclusion was that new water heaters were in order.In the end today I purchased two new brand new A.O. Smith water heaters, installed professionally, and again they they spent all afternoon trying to declog the shower hot water line. Seems is still way too much calcium and scale within the pipes. They blow out the pipes hot water, reassemble the valve, turn the shower back on, and it clogs right back up within 3 to 5 minutes. It is clogging the bathroom shower fixture mixing valve, to the point where there is no hot water. So these are my questions– – what’s the solution here? Is there a way to run a wire into the hot water lines to break up the suspected calcium in the walls of the pipes? Acid flush of the pipes?
And Shouldn’t the water softening system at some point rid me free and clear of continued calcium scale buildup?

 

[WorthFlorida]

What is the type of pipe is in your home? Take some of the scale debris and put in in a small glass with vinegar. If it effervescents, it is calcium.

A Google search on "how to remove calcium buildup in pipes"
You could use vinegar in the pipes, but it would take a lot of vinegar and you would have to leave it in the pipes at least 24 hours. You would have to remove all of the water in the pipes and replace it with vinegar. Vinegar dissolves calcium and minerals. Then you would have to flush your pipes.

Probably the soft water is slowly dissolving any remaining scale and it does seem that your plumbing contractor did all the right things to help it out. At a bathtub I would open the hot water side to full flow since and let the tub fill to see how much scale is coming through. The tub faucet is probably the only fixture to allow large volumes of water in the house. At the shower heads remove them for a while if you can shower without them just to allow time for the debris to be flush out. From what you stated the tub fill test may clog up the tub/shower cartridge. If it does and you know how remove it you can run the hot water without the cartridge at a slow rate to flush the pipes.

 

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[Reach4]

12 gpg is not unusually hard. That is to say that many people have water harder than that that never have those granuals. May I presume that your water heater was electric?

A lot attention has been paid to your solids already, but I would still want to confirm those are hardness materials by dissolving some in acid such as vinegar. Also confirm that your bits don't melt or burn in a flame. If it was bits of plastic it would be a shame to work hard to treat it as calcium+magnesium deposits.

I am not a plumber or other pro. This is an untested idea, and maybe flawed: Seems to me that you could rig something in series with your recirculation to run the water through a filter (to filter out particles) and circulate acidic water. Undiluted vinegar would be one way, but you I first thought you could carefully use HCl (muriatic acid). You would measure the pH with suitable test strips. Adjust for a suitable pH.... I am thinking around 3. Straight vinegar has a pH of about 2.5. So you could afford to fill the pipes being treated with vinegar, but I presume the reaction with the materials will deplete the vinegar. So drain some off and add more vinegar to compensate.

Using vinegar would be safer than HCl if your techniques were flawed. You can easily get standard vinegar for about $2.50 per gallon. I don't know how much you would need, but 2o gallons would not be expensive compared to everything else.

 

[WorthFlorida]

Right now there isn't a single bottle of vinegar to be had anywhere. Too many read that to use vinegar as a substitute for bleach and other sanitizers as a disinfectant.

 

[Reach4]

Right now there isn't a single bottle of vinegar to be had anywhere. Too many read that to use vinegar as a substitute for bleach and other sanitizers as a disinfectant.

I had not heard that. Interesting. I have 2 gallons of vinegar in case I decided to sanitize my well this spring. However I have not had any indication that my well needs re-sanitizing.

I know that vinegar +water +bleach makes for a much better disinfectant for wells than does bleach + water alone. But you don't want to mix bleach with straight vinegar, because that makes deadly chlorine gas.

 

[SK Sharma]

What is the type of pipe is in your home? Take some of the scale debris and put in in a small glass with vinegar. If it effervescents, it is calcium.

A Google search on "how to remove calcium buildup in pipes"
You could use vinegar in the pipes, but it would take a lot of vinegar and you would have to leave it in the pipes at least 24 hours. You would have to remove all of the water in the pipes and replace it with vinegar. Vinegar dissolves calcium and minerals. Then you would have to flush your pipes.

Probably the soft water is slowly dissolving any remaining scale and it does seem that your plumbing contractor did all the right things to help it out. At a bathtub I would open the hot water side to full flow since and let the tub fill to see how much scale is coming through. The tub faucet is probably the only fixture to allow large volumes of water in the house. At the shower heads remove them for a while if you can shower without them just to allow time for the debris to be flush out. From what you stated the tub fill test may clog up the tub/shower cartridge. If it does and you know how remove it you can run the hot water without the cartridge at a slow rate to flush the pipes.

Thanks. I'll try the vinegar test, but pretty sure its going to be a mixed mineral deposit.

 

[SK Sharma]

12 gpg is not unusually hard. That is to say that many people have water harder than that that never have those granuals. May I presume that your water heater was electric?

A lot attention has been paid to your solids already, but I would still want to confirm those are hardness materials by dissolving some in acid such as vinegar. Also confirm that your bits don't melt or burn in a flame. If it was bits of plastic it would be a shame to work hard to treat it as calcium+magnesium deposits.

I am not a plumber or other pro. This is an untested idea, and maybe flawed: Seems to me that you could rig something in series with your recirculation to run the water through a filter (to filter out particles) and circulate acidic water. Undiluted vinegar would be one way, but you I first thought you could carefully use HCl (muriatic acid). You would measure the pH with suitable test strips. Adjust for a suitable pH.... I am thinking around 3. Straight vinegar has a pH of about 2.5. So you could afford to fill the pipes being treated with vinegar, but I presume the reaction with the materials will deplete the vinegar. So drain some off and add more vinegar to compensate.

Using vinegar would be safer than HCl if your techniques were flawed. You can easily get standard vinegar for about $2.50 per gallon. I don't know how much you would need, but 2o gallons would not be expensive compared to everything else.

Gas heaters. Your plan is similar to what a plumber suggested: get a 55 gallon drum with a pump and isolate the hot water line to circulate a commercial grade acid. He's still researching what that might be. I have muriatic acid at home for my pool already. I could suggest this to him

One thing i'm wondering is the circulating hot water loop is likely pushing the detritus minerals to the whole house. Wondering if that line in particular needs a good flushing.

 

[Reach4]

Your plan is similar to what a plumber suggested: get a 55 gallon drum with a pump and isolate the hot water line to circulate a commercial grade acid. He's still researching what that might be. I have muriatic acid at home for my pool already. I could suggest this to him

I think a new clean plastic 33 gallon garbage can might be a good container if doing that. If you discharge low, and suck out water higher, I don't think you would need a filter to take out particles -- let them settle.

I was thinking of letting the recirc pump do the pumping, but having a separate pump would give you more flexibility.

Hydrion (325) Narrow Range pH Test Paper, 3.0–5.5 pH

seems about right for deciding if your acid needs refreshing.

 

[Reach4]

Very interesting. Never knew so much could get deposited. Reminded me of my father's by pass surgery thanks to 3 blocks!

Nor did I, and especially I did not know it would slough off like that. Your water may be less than average hardness for those who have a softener.