Is vinegar or descaler better for tankless water heaters?

Author: Mr. Reece Botsford Sr.  |  Last update: Friday, May 30, 2025

A tankless water heater descaler specifically designed for this purpose is recommended for optimal results. Alternatively, you can use vinegar as a natural and affordable descaling solution. Prepare the solution according to the manufacturer's instructions.

What is the best solution to descale a tankless water heater?

Use 4 gallons (15.1 liters) of undiluted white vinegar to clean your tankless water heater. Never use chemical solutions of any kind. Since your home's drinking and bathing water mostly likely flows through your tankless water heater, using chemical cleaning solutions could be extremely harmful to your health.

Does vinegar work as well as descaling solution for tankless water heater?

Ordinary vinegar will not work well to flush one of these tankless systems, it has to be WHITE vinegar, that has a much more active acidic reaction on hard water scale. IF THE VINEGAR DID NOT TURN GREEN then that is the problem.

Do all tankless water heaters need descaling?

Maintaining a routine descaling schedule is key to prolonging the life of your tankless unit, whether it is powered by electricity or gas. Most manufacturers recommend descaling your system once per year. For homes with hard water, equipment may require more maintenance.

Should I flush my water heater with vinegar?

To remove that calcium before it can block the tubes, and to improve the heating efficiency of the heater, we need to flush the tankless water heaters about once a year with vinegar. Vinegar is a weak acid which will dissolve the calcium.

How To Clean & Flush Tankless Hot Water Heaters with VINEGAR!

How long should I run vinegar through my tankless water heater?

Flushing Your Tankless Water Heater
  1. To begin flushing, open the hot- and cold-water ports, turn the pump on, and allow the vinegar to circulate for about an hour. ...
  2. Dump the vinegar from the bucket and close the cold-water service port.
  3. Remove the hose and open the cold water shut-off valve to flush any remaining vinegar.

How long will vinegar damage a hot water heater?

Cider vinegar is a mild acid that will not damage the water heater itself but can dissolve mineral buildup within the tank. Once you have let the vinegar work within the tank for several hours, re-open the valve and let water flow to flush the tank again.

How much does a plumber charge to descale a tankless water heater?

Flushing and descaling are important parts of that maintenance, no matter what kind of water you have. Descaling your tankless water costs between $150 and $450 on average.

How long does it take to descale a tankless water heater?

Open the service valves on the water heater. Turn on the pump to circulate the descaling solution through the water heater. Allow it to run for 30-45 minutes. Ensure the bucket has a minimum of 5 pints of water in it the entire time.

What happens if you don't descale your water heater?

Minerals such as calcium and magnesium tend to accumulate and build up over your water heater walls. This is especially the case if your groundwater is hard. Over time, the mineral build-up can reduce the heating efficiency of your water heater.

Is vinegar better than descaler?

Some articles likely mention using common household vinegar to descale, which unfortunately does not turn out to be very effective. Vinegar is very weak and mild acid which is not effective to remove limescale or rust. Plus, you run the risk of leaving a vinegar taste in your machine.

Can I use CLR to descale my tankless water heater?

Q:Can CLR be used to clean a tankless hot water heater? A: Jelmar DOES NOT RECOMMEND the use of CLR Calcium, Lime and Rust Remover in or on any water heaters (tank or tankless); however there is a website that does.

Is vinegar or descaler better for water heaters?

A tankless water heater descaler specifically designed for this purpose is recommended for optimal results. Alternatively, you can use vinegar as a natural and affordable descaling solution. Prepare the solution according to the manufacturer's instructions.

Is haymaker better than vinegar?

The Haymaker solution is 3 times as effective on scale as vinegar, and has no foul odor.

Do I need a descaler with my tankless water heater?

It's important to follow through with an annual maintenance regimen, which should include “descaling”. Descaling is needed, because much like removing the lime and minerals from a coffee maker, the waterways of a tankless water heater will build up similar mineral deposits.

Can vinegar be used to descale a coffee machine?

Descaling a coffee maker with vinegar is a simple way to keep your machine performing at its best. With filters and grounds removed, fill the reservoir to max using half water, half white distilled vinegar. Run a brew or cleaning cycle, empty the carafe and run 2-3 more brew cycles with fresh, cool water.

What happens if you don't clean tankless water heater?

One of the main reasons we perform water heater flushes is to remove sediment buildup. As water flows through your tankless water heater, it will leave behind small amounts of minerals and sediment. Over time, this can create buildup within the unit that may negatively impact the heat exchanger and restrict water flow.

Does vinegar work to descale tankless water heater?

Both vinegar and descaling solution work well for cleaning mineral deposits, calcium, and limescale from your tankless water heater.

How much does your electric bill go up with a tankless water heater?

How Much Electricity Does a Tankless Water Heater Use? Many people wonder if tankless water heaters increase electric bills. The answer is no — tankless water heaters can save money on your monthly electric bill because they're 8%-34% more efficient than storage water heaters.

How often should I flush a tankless water heater with a water softener?

If you have hard water, it is important to descale and flush your unit at least once a year. If you have a water softening system, we recommend performing a flush of the system every 3-5 years.

How much vinegar do you need to descale a hot water heater?

Disconnect the cold-water inlet, hot water outlet, T & P valve, or element holes and, using a funnel, pour one (1) gallon of regular household cider vinegar into the water heater. (Do not dilute with water) ** NOTE: For Electric Heaters, it is recommended you remove the elements from the heater and lay them in a pan.

Is CLR safe for a tankless water heater?

No, Jelmar DOES NOT RECOMMEND the use of CLR on a water heater; however, there is a web site that does. Again, JELMAR DOES NOT RECOMMEND THE USE OF CLR IN A WATER HEATER.

Will vinegar hurt a water pump?

When learning how to clean a fountain pump, vinegar is a better solution than any soap and water. Vinegar is used to break down mineral deposits that can collect over time. For areas with hard water, more frequent cleaning may be needed – approximately every two weeks.

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