How to Put Vinegar in an RV Hot Water Heater

Hot water is another awesome RV convenience that will come in handy. Taking a shower without needing a hotel room, bus stop, or random beach shower is a great feeling. Doing dishes is certainly helpful too.

Hot water heaters do require some maintenance, especially when getting water at RV stops. Some parts of the country also have higher concentrations of minerals and other things that can build up in your RV’s hot water heater. Vinegar use helps get rid of these.

Not many people have tried to put anything in their hot water heater. Methods include pouring the vinegar in through the exterior of the RV or opening the top of the hot water heater tank.

Safety precautions in getting vinegar in your RV hot water heater

Regardless of how you access your RV hot water heater’s tank and water, you’ll want to turn your hot water heater off and let it cool down. You’ll also want to turn off the supply of propane.

Both are necessary because your hot water heater produces hot water – obviously, and could burn you if you touch the water directly in the tank.

The on and off switch for your propane should be near the tank, probably close to the wall. The on off switch for the heater itself is likely on the floor or somewhere midway up the tank.

Let the tank cool for as long as it needs to avoid having hot water splash on you during the following steps. 

How to put vinegar into your RV hot water heater via the outside

This method involves using your RV’s gravity port. The gravity port allows water to flow into your RV fresh water tank. Some RVs will not have a gravity port but support a threaded connection for a hose.

You’ll want to open the gravity port if it has a cap. Ensure the fresh water tank has some water in it too. Pour the mixture of vinegar into the tank and let it flow in. Put the cap back on the gravity port if necessary.

Using the pressure relief valve to pour vinegar into your hot water heater

This one is a little more difficult. You may also want to read your RV and hot water heater manual first. 

There is a valve near the top of your hot water heater that releases heat if your water heater gets too hot. 

  1. Locate the pressure relief valve
  2. First, take a picture of the pressure relief valve to ensure you remember how it goes on. Remove the pressure relief valve. This can be as simple as turning a crank on the outside. Generally, the easiest way is with a large adjustable wrench. You might also need a screwdriver to remove any plates around the pressure relief valve. 
  3. Pour the mixture of vinegar directly into the top of the water heater’s open pressure relief valve.
  4. Put the pressure relief valve back on the way it was. This is an important element for the water heater so be sure it’s back in nice and tight.

Having the pressure relief valve off can also give you a glimpse inside your tank, if you are tall enough to see it. You could also stick your phone camera near the opening to see the inside. This can give you a good idea as to how badly the tank needs cleaning.

How to get the vinegar into the tank

You are almost there! Regardless of your method of getting vinegar into the hot water tank, you’ll want to turn your hot water heater back up.

Turn the liquid propane back on, then switch the water heater itself back on. Let the water heater heat up and warm up the vinegar.

If you want the vinegar to really sit in the water heater, we suggest not turning on any hot water. Also, any hot water you receive while the vinegar is sitting in the tank will smell and taste like vinegar, of course.

Heating the water will allow the vinegar to take it’s full effect of remove sediment from your tank. 

How to get vinegar out of the tank

Water heaters generally have drains that sends the water back into the gray water tank.

Turning the drain on should let the hot water and vinegar into your gray water or black water tank.

Another option is to use the hot water and vinegar mix to clean your sink and shower. Turn on the hot water and the combination will come right out. We’ll also warn ou not to combine bleach products with this process as bleach and vinegar or ammonia create a toxic gas.

You could also just drain the water directly into the sink or shower without cleaning it at the same time – entirely up to you.

RV owners will also likely want to drain their grey or black water tank after draining the entire hot water heater into a tank.


Cleaning out your hot water heater tan is a good idea for routine maintenance. The water heater can receive water from many sources as you travel, and minerals and sediment can build up. The gradual build up can lead to the need for further repairs or an inefficient heater – as well as harder water.

Get your funnel and potentially screwdriver and adjustable wrench ready. You’ll quickly learn the easiest way to get into your hot water heater’s access ports and be well on your way to cleaning out the inside.