Calcium Buildup in Drains/Pipes? Dissolve & Remove it

Slow draining fixtures, weak flushing/slow drain toilets and low water pressure in the house can be caused by calcium build up. Calcium is the main mineral in hard water and it coats the inside of drains and water pipes reducing their internal diameter, subjecting them to clogs and as well as reducing water pressure.

Calcium deposits can also settle at the bottom of the water heater effectively reducing its volume and efficiency. This is why flushing the water heater at least once a year is recommended.


The best and long-term method to prevent calcium build in pipes and drains is replacing your old pipes with PEX or/and installing a water softener. To remove calcium buildup, dissolve it using vinegar and baking soda or a chemical/acidic drain cleaner. Chemical drain cleaners should not be used in water pipes.

Apart from clogging water pipes and drains, calcium and other minerals found in hard water can discolor fixtures like toilets, sinks and bathtubs. Installing a water softener and cleaning the fixtures using vinegar and baking soda or borax will help remove the calcium build up.

Calcium will especially clog the tiny holes found in shower heads and faucet aerators. Removing and soaking shower heads and faucet aerators in distilled vinegar will dissolve the calcium thereby opening up the holes.

Chemical drain cleaners like CLR will dissolve calcium buildup in drains but they are not eco-friendly and are not recommended especially if you are on a septic system. The chemicals will kill the good bacteria in the septic tank, which is what breaks down the waste.

CLR and other chemical drain cleaners should not be used to remove calcium and other mineral deposits in water pipes. They are toxic and ingesting them will result in health hazards.

The best way to dissolve calcium buildup in water pipes is by turning off water to the house, draining out all the water and replace it with vinegar. Let the vinegar soak up and dissolve the calcium and other mineral deposits for 24 hours then flush it out with water.

A vinegar taste will linger in your water for a while but it is completely harmless. The only problem with this method is that you will be without water for 24 hours.

How to Remove Calcium Build Up In Pipes

calcium buildup in pipes

To be very honest with you, it is not easy to get rid of calcium build up in water pipes. But you can try. You will need a lot of vinegar (depending on the size of your house) and you will be without water for  up to a day.

Here are the steps to follow:

1. Turn off and Drain the Water

Before turning off water to your house, you will first need to fill several pots/buckets (or even a barrel) with water for your consumption throughout the day. You may have to flush toilets with a bucket.

The next step is to turn off power or gas supply to your water heater. If you do not water to mess with the water heater, you can bypass it by turning off the cold and hot water shut off valves.

Bypass other appliances like washing machines, dishwasher, refrigerator icemaker/dispenser etc.

To turn off water to your entire house, look for the main shut off valve where the main water line from the street enters the house. This could be on an external wall or inside the house in the basement, garage or crawlspace.

After turning off the water, open all the water faucets to drain the water already in the pipes. Don’t forget to turn off outside faucets as well as flushing all the toilets.

2. Remove and Soak Aerators and Shower Heads in Vinegar

If you look at the tip of your faucet spouts, you will see a small attachment whose opening looks like a mesh. That is called a faucet aerator.

A faucet aerator introduces air into the water which helps to increase the spray width, prevent water from splashing back at you and also makes it soft to the touch.

Faucet aerators and shower heads are easily clogged by calcium deposits. Use a wrench to remove the shower heads or check out this post for more information.

While removing aerators, you need to be very careful not to peel off the finish with a wrench. Wrap a cloth or tape on the aerator then grab on it with the wrench to safely remove it.

Fill a small bucket with vinegar then drop in the faucet aerators and shower heads. Let the vinegar dissolve the calcium deposits.

Since you will also need to clean the shower head water pipe, plug off the connection and leave the shower faucet open (or tub faucet diverted to the shower).

Turn off all the other faucets.

3. Pump in the Vinegar

With water to the house turned off and all the pipes drained, it is time to pump in the vinegar. To make sure you have no air trapped in the pipes, open the faucet at the furthest or highest point of the house to flush out the hair.

Pump in the vinegar until it starts to shoot out from the faucet you left open. Turn off the faucet at that point. You need to fill both the cold and hot water lines with the vinegar. As I said, you will need a lot of vinegar.

Let the vinegar sit in the pipes for up to 24 hours.

4. Flush out the Vinegar

After you are sure the vinegar has sufficiently dissolved the calcium build up in the pipes, turn on all the faucets to remove it. Let the faucets run until nothing is flowing out anymore.

Turn on the main water shut off valve and let the water blast out of the faucets at full pressure to flush out the vinegar and calcium debris still trapped in the pipes. Open the cold and hot water shut off valves on the water heater and turn it on as well.

When you are sure that the vinegar and calcium deposits have been flushed out, it is time to turn off the faucets. Again, you will need to be methodical to be sure you do not have air trapped in the pipes.

Start by turning off faucets closest to the shut off valve and work your way to the faucet furthest from the valve, or the one at the highest point of the house.

When that is done, connect back the shower heads and faucet aerators. You may need to scrub the aerators with a toothbrush to completely clear them. Poke through each hole on the shower heads using a toothpick.

And basically that is how to dissolve and remove calcium buildup in pipes.

What About Drains?

If you have a slow draining fixture and you suspect that you have calcium buildup in your drainpipes, vinegar and baking soda will very well help you dissolve the calcium and clear your drains.

Every fixture in your house (toilets, sinks, washing machines, tubs and shower drains) has a U-bend called a P-trap or drain trap. You can see it under your kitchen/bathroom sink. It is what allows you to have water at the bottom of the toilet bowl.

Washing machines and shower/tub drains also have P-traps only that you cannot see them.

A P-trap has 2 functions. It hold a little amount of water that acts s a sewer gases barrier and also traps potential drain clogs. It is easier to unclog a trap than a clog a farther down in the drainpipe.

It is therefore true to say that it is very easy for calcium deposits to build up inside the drain traps of your fixtures, restricting the flow of water. It also makes the drains clog easily.

For a toilet drain, I suggest you start by removing the water at the bottom of the bowl. You can either force it down the drain using a plunger, or soak it up using a cloth/towel.

For a sink , washing machine and shower/tub drain, pour half a cup of baking soda down the drain then slowly add 1 cup of vinegar. A toilet has a bigger trap so you should use 1 cup of baking soda and 2 cups of vinegar.

Baking soda (alkali) and vinegar (acid) will react (fizzle) and break down the calcium buildup. Leave the solution to sit in the drain trap for 2-3 hours.

Don’t flush the toilets, open sink/shower faucets or run washing machine during that period.

After 2-3 hours, dump a gallon of boiling water down the drain to flush out the broken down calcium deposits. Do not use boiling water in toilets and tubs. Normal hot water from faucets will do it.

This method can only be used if the calcium build up is in the drain trap. If the calcium buildup affects the entire length of the drain or sewer pipes, you will need something stronger.

Is Hydro Jetting a Good Option?

So, what is hydro jetting?

Hydro jetting is a way of cleaning drains using pressurized water. A thin flexible hose with a nozzle head is fed into the drains via the drain cleanout where it blasts out water under pressure and in the process scouring out lime scale and other clogs from the drains.

After locating the drain cleanout, the plumber will run a camera through the drain to access its condition. This is important in finding out if hydro jetting is the best course of action for the problem.

If they are sure that hydro jetting is the way to go, they will insert the hose inside the drain and adjust the water pressure up to 3500 psi (pound per square inch).

The hose head moves upstream inside the drain scouring out calcium buildup while the same drops off and washes downstream via gravity.

This method is without a doubt expensive but it will be the only viable one in some cases.

As I mentioned earlier, installing a water softener is the best and long-term method of preventing calcium build up in pipes.

Leave a Comment