Friday, June 2, 2023


Got hard water problems? Try vinegar!

By Russ and Tiña De Maris

Having spent a number of years in the “naturally soft water” country of the Pacific Northwest, it was a shock to us when we learned about the effects of hard water on RV plumbing. In a few short months we helped out with a number of RV plumbing failures in the Southwest, all related to hard water. Seems like the stuff makes deposits inside pipes, and can even eat through fittings.

Some swear by “the vinegar treatment.” Once a year, it is said, a solution of white vinegar and water should be pumped through the RV water system, allowed to sit and dissolve hard water deposits. We haven’t tried it yet, so if you’d like to be an RV Guinea Pig, let us know how it works.

First, turn off your “city water” supply and the power or gas to your hot water heater. Drain your hot water tank and, if you have one, use a tank flusher like this one from amazon to scour the inside of the tank to blast away “klingons.” Close the drain fitting when your swish-out job is complete. If your heater is equipped with an anode rod, take it out (temporarily) and replace it with a plastic plug – you should be able to find a suitable plug at the hardware store.

Next, if there’s water in your fresh water holding tank, drain it out. Now turn on the RV water pump. Open all your water-flowing fixtures and run them until air spurts out. Turn off the fixtures and water pump – you’re ready for Phase 2.

Tell tale signs of hard water corruption. R&T De Maris photo.

You’ll need plenty of white vinegar. We’d recommend dumping about 4 gallons of the stuff into your fresh water tank, along with an equal amount of fresh water. If you can, drive your rig “around the block” to swish the solution around in the fresh water tank. Of course, you took the time to close the fresh tank drain valve before pouring in the vinegar!

Back home, turn on the water pump. Open your valves, one at a time, and let the water flow until you smell that good old strong vinegar odor. Close the valve, and repeat with all the fixtures in your rig. You’ll also be doing the “hot” side, so your hot water tank will fill with this same solution. Allow the solution to “sit” for several hours–overnight would be good if you can.

Afterwards, drain your fresh water holding tank and hot water tank. Refill the fresh tank with fresh water, and thoroughly run all fixtures until the odor and any color is gone. You may need to do this several times to get all the hard water minerals out of the system. Be sure to replace your anode rod!

Here’s another trick: If your shower head is likewise besieged by the hard water army, take it off the connecting hose and soak it in straight white vinegar overnight. Then rinse it thoroughly and replace.



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2 years ago

Vinegar (even high acidity vinegar) doesn’t remove ALL hard water deposits. Where I live, there’s a lot of iron and other minerals in our well water in addition to calcium. Vinegar removes calcium deposits but it doesn’t touch the scale from the other minerals. (Even after days of soaking in high acidity vinegar.)

Brian Gilbert
2 years ago

Why allow the mineral buildup occur in the first place? A portable water softener eliminates the problem entirely. We purchased ours online about five years ago for around $150. It is recharged with plain table salt. It requires no electricity.

It not only eliminates mineral buildup and damage, but you also get the additional advantage of much improved showering and shampooing. It’s probably the best accessory I’ve purchased for our motorhome.

Tommy Molnar
2 years ago
Reply to  Brian Gilbert

I just bought one of those portable water softeners last year. Liked it SO much we had a home unit installed in our house when we returned from our extended trip. What a difference.

My only complaint is that the portable unit is NOT light so now I’ve got yet another heavy ‘thing’ to cart around with us when traveling.

2 years ago

I coat my cruddy faucets with ketchup. Leave it overnight and they come out like new.

3 years ago

A quicker way to clean your bathroom shower head is by putting vinegar in a baggie tie or fasten over shower head, making sure there is enough vinegar to cover the whole shower head. Leave on overnight and the next day it will be nice and clean. DO NOT DO THIS WITH A METAL SHOWER HEAD – it ruins it’s finish. Works great on plastic shower heads.

3 years ago

You can actually use vinegar as a sanitizer. It kills microbes.
Of course, bleach is much cheaper to use as vinegar has to be used at much higher concentration to be effective.

Another great use for vinegar is getting rid of mold. It works great. I had a car that sat unused for about 6 months and had a small water leak into the trunk. The back dash got quite moldy from it.
A 20% vinegar and water solution and a rag took care of the problem.

Vanessa Simmons
3 years ago

Once you do this remove the aerators from the faucets and clean out the gunk trapped in them from your cleaning…or remove them before you start.

Chris Ingmanson
3 years ago

The vinegar does work well however, I would add a caution. If it has been awhile and you have build up from hard water, the vinegar may work too well and release some deposits that can clog parts of the plumbing. Learned from experience and had to dismantle the toilet rinse drain which had a smaller tube. Since then, no problems.

Malcolm Benson-Dyke
3 years ago

I ran white vinegar through my entire fresh water system last winter in Arizona.
I used the winterizing kit and sucked the vinegar up through the hose and waited until I could smell it at each faucet. I did bypass the hot-water heater. I let the vinegar sit in the lines for a couple of hours, and then flushed all the lines out with fresh water. Could not believe the difference in water pressure. Probably 75-80% better.
This will now be part of our regular maintenance every year.

John S.
3 years ago

Yes, white vinegar works extremely well! It also is great on French Fries! But why wait until you have plumbing problems. I tried a product called “NUVO H2O” in my A class coach and never had a problem or need to dissolve build up with white vinegar. At first I was hesitant to try it. It is basically a citrus impregnated filter cartridge that is housed in an fancy water filter housing. Initial purchase price was expensive but you can buy a standard housing (save $250-$300) at Lowe’s or Home Depot and buy the cartridge from NUVO H2O for about $50 for the “Studio” size, ideal for most RV’s. Cartridge is good for six months. When you are nearing replacement time, call the toll free number and they deliver right to your door included in the price. Hook it up to your water like any other filter systems and you won’t have the buildup issue again. It will also help break down existing build up but not as fast as white vinegar will.

Colin Grant
3 years ago

Buy pickling vinegar which is 10% acetic acid not the regular which is 5% acetic acid and the price difference is usually $1.00 for a gallon.

3 years ago

If you add the vinegar first and then fresh water you won’t need to drive the RV to “swish” the solution. The water pressure from the hose will do it.

Another use for vinegar is after sanitizing the tank with the bleach. After draining the bleach water we then add a gallon of vinegar, refill the tank and then drain with the fresh water pump. The vinegar removes the taste of bleach and the vinegar taste quickly dissipates.

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