Will Vinegar Damage A Hot Water Heater: My Honest Opinion

Beginner Info, Tankless Water Heater

Will Vinegar Damage A Hot Water Heater
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Definitely, a good question, indeed.

Let’s figure out whether vinegar will damage a hot water heater or NOT.

Well, to begin with, please allow me to share an interesting story of one of my clients and what inference can we draw from it.

Mr. David Hudson was a resident of a region that constitutes minerals such as iron, calcium, etc in abundance in the incoming groundwater to the heater.

In layman’s terms, the water was very hard which implies that the probability of mineral buildup is huge.

The worst part was, David has never flushed his 4 years old water heater which has a 40-gallon capacity and uses natural gas as fuel.

Some of the issues that he was dealing with were boom sounds, audible snaps, crackles, etc.

Quite a few times, David thought of selling the hot water heater.

However, his wife suggested him for taking the help of a certified technician and figure out the solution to this idiosyncratic problem.

Well, many first-time water heater buyers would be able to correlate with this problem for sure.

David interacted with a couple of plumbers and finally, decided to take help from one of them.

So, after brainstorming for a tangible amount of time, both David and Plumber decided to expedite the below-mentioned steps and see whether the outcomes are encouraging or NOT.

  • First and foremost, he drained the tank
  • Secondly, he added two gallons of white vinegar to the tank which has a capacity of 40 gallons
  • Then, he left them as it is for the next 12 hours, and at the 6th-hour mark David was asked by the plumber to ignite the burner for a couple of minutes
  • The next thing that David did was to flush the tank in the best possible manner under the guidance of the plumber
  • And, the plumber said him, lastly to repeat the aforementioned steps if the problem persists

Can you guess the outcome?

Well, after expediting the aforementioned steps for the very first time, most of the issues, were either solved or their intensity decreased drastically.

He expedited the aforementioned steps twice every year, and his water heater is still doing fine with some problems here and there.

I hope the example clearly depicts the importance of vinegar in cleaning a hot water heater, isn’t it?

Does vinegar doesn’t have any flaws?

Frankly speaking, it’s NOT TRUE…

Like any other product in this world, vinegar also has its share of pros and cons.

In fact, vinegar is acidic so it may attack steel as the water and acid can cause rust, and rust may lead to holes in the structure leading to leakage.

So, what is the best way to protect a water heater?

Well, the best way to enhance the longevity of a tankless water heater is to prevent the hard water scale buildup in it.

And, the best way according to me to do it is by using a water softener like the one that I’ve been using as well as recommending it to my clients.

 Many first-time buyers and newbies wouldn’t be aware of the fact that “snap, crackle, pop” is due to little steam explosions in the accumulated layer of mineral sediment on the tank floor. 

It is really important to dig into the sound issue and figure out the reason for it.

Without knowing the reason you’ll not be able to find a feasible solution for sure.

Let’s understand it with the help of an example.

Well, if the cause of the noise in the aforementioned example would’ve been the breaks in the gas lining, then you know what, adding vinegar wouldn’t be able to resolve the issue for sure.

As per my knowledge and experience, the addition of a tangible amount of vinegar might aggravate the intensity of the problem.

 On the other hand, if the cause of the unwanted and weird noise is related to a layer of sediment buildup, then adding vinegar will definitely, help you in resolving the issue by dissolving the sediments effectively. 

In the case of gas and oil heaters, the heat is mainly applied on the outside bottom of the tank on naked steel.

As a result, the scale is on the glass lining inside the tank.

And, once substantial scale buildups, then the probability of steam explosion increases tremendously.

Moreover, steam is powerful and so the force doesn’t strike in one direction but rather goes in every possible direction.

Irrespective of the type of hot water heater that you own, it is your responsibility to ensure that is to keep the scale from forming in the tank.

And, trust me, the best and the most effective way to do it is to remove the hardness with a high-quality softener.

To be honest, I’ve come across quite a few gas and oil heaters in which the scale isn’t only on the bottom but also, it’s on the walls and flue pipe.

However, the case of an electric water heater is a bit different.

In case, you own an electric water heater, then you must be aware of the fact that the scale forms on the elements.

And, in extreme cases, it might break them due to either expansion or contraction, and if that happens, then you’ll find some structure resembling a half circle to the bottom.

Trust me, they might not be impossible to drain out but definitely, hard enough to bring you on your toes for sure.

Will Vinegar Damage a Hot Water Heater?

As mentioned earlier, vinegar is a homemade cleaner that is free from harmful chemicals.

The sediment build-up can be easily removed from the bottom of your tankless water heater with the help of a vinegar solution considering the material to be stainless steel.

At the same time, we don’t recommend allowing the vinegar solution to be soaked for an extended duration as it may damage the base of your tankless water heater and the result may not be satisfactory as well.

Once you’re done with cleaning the base as well as the sides of your tankless water heater, make sure to rinse off the vinegar solution in the best possible way so that no residue is left which may damage the base of your tankless unit.

What I actually wanna convey is that vinegar doesn’t impact your tankless unit adversely if used in a correct manner.

In fact, you need to thank vinegar to be so natural and free from harmful chemicals.

All you need to do is to make sure that the surface and walls of your tankless unit are free from vinegar residue post-cleaning.

Yes, it’s as simple as that.

Can I Put Vinegar in My Hot Water Heater?

You tell me, can we put vinegar in our hot water heater or not?

Of course, you can put vinegar or its solution in your hot water tankless water heater.

Vinegar is a natural compound that is free from any toxic elements so it will not create any problems when kept in a tankless hot water heater.

As we all know, vinegar contains acid that will react with buildup in your hot water heater and thus, will remove the scale in an epigrammatic span of time.

Vinegar is safe when used against stainless steel hot water heater as it will neither rust the former nor will encourage leakage.

For the optimum result, you need to rinse your hot water heater thoroughly post-cleaning with vinegar.

Steps Involved in Cleaning Hot Water Heater Using Vinegar

In order to reap optimum benefits from a vinegar solution, you need to follow the below-mentioned steps.

  • Important types of equipment that you need
  • Turning off your hot water heater
  • Cleaning the valves
  • Cleaning the pre-filter
  • Expediting the flushing process
  • Finishing up

Please allow me to throw light on each step so that you make an informed decision.


Even before starting the cleaning process using vinegar solution, you need to make sure that you’re handy with the below list of equipment.

  • Three gallons of regular household vinegar
  • A couple of regular washing machine hoses
  • A submersible pump
  • A 5-gallon bucket

Turn Off Your Water Heater

You need to turn off your hot water heater by pressing the ON/OFF button.

Also, you need to ensure that the gas supply is turned off which can be done by locating the valve very close to the water heater and then setting it to the off position.

Clean the Valves

This is an important step and needs to be performed in the best possible ways.

All you need to do is to put a 5-gallon bucket right underneath your hot water heater.

You must have a set of valves to adjust underneath your tankless unit.

Three valves would be present which are blue, red, and yellow in color, and are meant to control the water that goes into the hot water heater and out.

All these valves need to be closed and then the flow of water should be stopped from the unit.

Once done, you need to remove the protective caps on the end of the flushing valves, and then each valve needs to be opened up slowly.

To being with, the blue valve should be given priority as you’ll find a little bit of water coming out from it.

You can find a good amount of water pouring when you’ll try to open the red valve.

Furthermore, you just need to wait until all the water drains out.

Pre-Filter Needs to Be Cleaned

Yes, you heard it, right?

It’s high time to expedite the pre-filter cleaning process.

You need to rinse the pre-filter because the tankless unit has a small screen that is uniquely designed to protect it if anything gets into the pipes.

The good thing about most water heaters that we recommend is that pre-filters are present outside of the heater itself.

You must locate it and unscrew it by using a small pair of channel locks.

If you’re not cleaning pre-filters on a regular basis then it may lead to buildups.

And, as a result, the water flow can reduce drastically.

We at izzysmarthomeguide.com recommend our client maintain the prefilter properly by cleaning the dirt buildups using a toothbrush or a similar device.

The next thing that needs to be done is to rethread the filter screen right back into its position.

Time to Flush & Clean Your Hot Water Heater

The washing machine hoses need to be threaded to the ports on the flush valve.

If you’re not sure how to do that then you can contact a technical expert.

Then, you need to connect the blue hose to the top of your submersible pump.

Now, it’s high time to use the submersible pump to pump the fluid up into your hot water heater system.

The red hose needs to be hung into the bucket as the red hose is in the return line.

Once the aforementioned steps are expedited, the next thing that needs to be done is that the submersible pump needs to be put directly into the bottom of the bucket.

Moving further, you need to pour three gallons of vinegar into the bucket.

It’s time to plug the pump and turn it on.

The submersible pump has an important role in pumping the vinegar into the hot water heater through the blue hose and the vinegar will come back into the bucket through the red hose.

As we all know that vinegar contains acid which will eat up any kind of mineral buildup, calcium, or other deposits inside the heat exchanger.

Don’t take your eyes off the bucket in order to ensure nothing spills out.

Furthermore, you need to leave the pump running for 45 to 60 minutes, and post the running you’ll definitely see the clean solution turning nasty because of the cleaning of the buildup.

Finishing Up

This is the final step wherein you need to remove the buildups from inside of your hot water heater.

Furthermore, you need to unplug the pump and close the red and blue valves on top of the manifold.

Afterward, you need to remove the hoses as well as put the protective caps back into their places.

Furthermore, the hoses need to remove, and then you need to put the protective caps back into their places.

The submersible pump needs to be removed from the bucket and then the solution needs to be dumped outside.

You need to turn on the hot water position and then turn both of those valves back to their original position.

By doing so, you’ll be able to flush out a little bit of vinegar that was still inside the hot water tank.

Lastly, you need to turn the gas valve back to ON as well as turn the power back on your tankless hot water system.

Don’t worry, if you’ve some air in the pipes, it will go away in a couple of minutes once you’ll turn the water back on.

Finally, your hot water is ready for work for at least a year.


In this section, I would be responding to the queries related to the topic in order to help you make an informed decision.

What kind of vinegar to flush a tankless water heater?

We at izzysmarthomeguide.com recommend white vinegar to flush a tankless hot water heater.

Make sure the solution is properly diluted so that you can reap maximum benefits from it.

If the base of a tankless water heater is exposed for a longer duration to a highly concentrated vinegar solution then it may lead to damage.

However, as compared to a chemical cleaning agent, vinegar solution has an upper edge as it is non-toxic and doesn’t consist of any chemical agent.

Cider vinegar is equally good for cleaning your hot water heater.

Will vinegar dissolve water heater sediment?

It goes without saying that vinegar will dissolve water heater sediment and for the same reason it is one of the best cleaning agents for your hot water heater.

All you need to do is to pour vinegar solution into your hot water heater and leave it for at least 24 hours for reaping maximum benefits.

The acid present in the vinegar will slowly and gradually dissolve the buildup sediments over a period of time.

Finally, sediment deposits should be removed by flushing your hot water heater with clean water.

How do you remove calcium deposits from a hot water heater?

Needless to say, vinegar is an effective cleaning agent that doesn’t contain any toxic elements and therefore you can rely on it to remove calcium deposits from your hot water heater.

Calcium deposits can be removed in a couple of hours by just pouring water and vinegar into the unit.

The acid present in the vinegar is capable of dissolving calcium buildup in a couple of hours.

Lastly, wash away your hot water heater with clean water so that residue is removed from the unit.

Can I put CLR in my hot water heater?

Yes, you can put CLR in your hot water heater.

The cleaner is capable of eating away the calcium deposits and other buildups present at the bottom of the tankless unit.

If you’re putting CLR then you don’t have to scrub the bottom of your tankless unit for removing the deposit, interesting, isn’t it?

What’s the difference between vinegar and lemon juice?

What puts vinegar apart from lemon juice is the type of acid present in it.

Lemon juice is on average five to six percent citric acid.

On the other hand, vinegar consists of acetic acid.

Different types of vinegar consist of different percentages of acetic acid.

For example, white vinegar tends to have seven percent acetic acid which is higher compared to other types of vinegar.

Balsamic and red wine vinegar is milder vinegar and consists of six percent acetic acid.

Lastly, rice wine vinegar is around four and a half percent.

In terms of pH, vinegar is slightly more acidic than lemon juice.

What’s the difference between vinegar and cider vinegar?

Apple cider vinegar contains about five to six percent acetic acid, while white vinegar contains five to ten percent.

The higher concentration of acid makes most white vinegar more acidic than their apple-based counterparts.

What’s the difference between rice vinegar and white vinegar?

White vinegar is made by fermenting grain alcohol whereas rice vinegar is made from fermented rice.

Rice vinegar is less tangy and acidic than white vinegar, with a subtle sweetness.

White vinegar is sharper, and harsher and comes with a neutral flavor.

What can I use instead of white vinegar?

Let’s have a quick look at a few alternatives to white vinegar.

Baking Soda

Like vinegar, baking soda is a kitchen staple that you can use for your cleaning chores.

But at the same time, you need to understand that, unlike white vinegar which is acidic, baking soda is alkaline.

Baking soda is generally used for cleaning surfaces such as marbles and is best used for scrubbing grime buildup on different areas of your home.

Baking soda can be used for cleaning in the form of paste or solution.

Liquid Dish Soap

Needless to say, liquid dish soap solutions are among the most effective cleaners and perhaps the best when it comes to cleaning dirty surfaces in your home

The only downside I see when it comes to cleaning with soapy water is that you’ll have to rinse the detergent residue.

On the other hand, vinegar evaporates.

Hydrogen Peroxide

Hydrogen peroxide could be a viable option if you’re looking for an eco-friendly cleaning agent.

Compared to vinegar, hydrogen peroxide is better at cleaning bacteria, fungi, and viruses.

In order to disinfect a surface, you need to use a 50/50 hydrogen peroxide and water solution.

Spray the solution on the dirty surface and allow it to sit for at least 5 minutes and then rinse it off.

Other Types of Vinegar

As discussed earlier, different types of vinegar contain different percentages of acid.

You can use other types of vinegar for cleaning purposes as well.

Wrapping Up

First and foremost, I would like to thank you for being with us till the end.

Secondly, I would like to bring to your notice that I along with my team have worked extremely hard to come up with this idiosyncratic superlative explanation.

And, in case, you liked our effort and want to appreciate us, then feel free to share this piece of information with the ones who are in need of it.

After all, sharing is caring, isn’t it?

Coming back straight to the topic will vinegar damage a hot water heater, all I can say is it DEPENDS.

If you’re successful in finding the root cause of the unwanted sounds in your hot water heater.

And, if the cause is due to the accumulation of sediments, using vinegar in adequate quantity will definitely, help you to get rid of the problem.

However, you also need to understand the vinegar if used in excessive amounts more frequently than required can aggravate rust formation which can further lead to leakage in your hot water tank.

To conclude, I would suggest you gather the necessary information about the pros and cons of using vinegar in your hot water tank, and then act smartly to reap optimum benefits out of it.

That’s all, I’ve to say as of now.

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