Informational Guide

How To Drain RV Water Heater

by Ian Haynes

The water heater in your RV is a great way to give you hot water for cooking and bathing while on the road. Maintaining them will ensure that you are not left out in the cold when it no longer heats up the water as you expect.  

Our guide will help you learn why you need to drain out your RV hot water heater to help with routine maintenance. Let's dive in and learn more about the steps you need to take to keep the RV water heater working well.  

tankless water heater on RV

RV owners should consider draining out their RV water heater. This is part of the routine maintenance that the water heater needs. You should do this a minimum of once a year. Many RV owners will do it in the winter when it is time to winterize the unit and get it ready to store until the next season.  

When the water is allowed to stay in the RV, it could result in a foul smell that is hard to remove. Without draining out the system, the water is allowed to remain dormant and will just sit in the system. This makes the perfect environment for harmful bacteria to grow, which will damage the RV’s water tank.  

When you drain out the water, it flushes out all the bad stuff and makes sure water does not just sit there. This will help the RV water heater to last for longer. Some recommend that you change it after each use. If you go out every week, it is not likely that the water will lay dormant and get bad, so you may not need to drain each time.  

If you plan to have a longer time between uses for the RV, or you are getting ready to winterize the RV and store it, then you need to drain the water. This will help the water heater to last for a decade or longer.  

How To Drain A RV Water Heater: Step-By-Step Guide 

Drain A RV Water Heater

Draining the RV water heater is simple, which helps make it easier to accomplish. Some of the steps you can use to do this include: 

  • Step 1:
    Turn off the water pump, LP gas, and water heater. If the RV is hooked up, turn off the city water supply. Take the time to disconnect the hot water bypass and revert it to the standard setup you use if you are taking the RV out of storage. 
  • Step 2:
    Run the hot water in the RV. Keep it on until the water is cold. This will make sure that the water is safe and cool when you do the rest. When the water is cool, go to the outside and open the water heater panel. 
  • Step 3:
    Open the pressure valve. This is on the top of the water heater. An adjustable wrench will help you loosen the drain plug. Remove this plug so the water can run out. Wait until water stops coming out of the heater. Replace the plug, close the pressure release valve, and rinse off the area. Close the panel door. 

The tools for draining the RV water heater are not complicated. You can do most of it by yourself without additional tools. A wrench will help with the valves if they are stuck or you have not drained them out for some time. However, if you are bringing the RV out of storage from the winter, you may need a few other tools to make sure you can get the camper prepared for use.  

Draining Popular Models Of RV Water Heaters 

Popular Models OF RV

Most models of RVs will utilize the same type of system to drain out the water heater. This can make it easier for consumers who may switch brands to figure out how to get the water out. Some of the steps that you can take to drain out the water in popular RV models include: 

How To Drain Atwood RV Water Heater? 

To drain an Atwood RV water heater, you will need some white vinegar, a tank flush wand, and a wrench to move the drain plug. The vinegar will help you clean out the drain while you do the work and can kill off the bacteria that may be inside. You can drain the water heater without it if you don't have any on hand.  

Turn off the water heater and water pump before you start. Let the water run through until it is cold. Then, use the wrench to open up the drain plug and let the water run out. If you are cleaning with the vinegar, add that in and let it flush through to help clean out the system.  

How To drain Suburban RV Water Heater? 

If you have a Suburban RV water heater, there are a few steps that you can take to help drain it out. These include: 

  1. 1
    Check the water heater bypass and make sure it is in normal mode. Turn off the water pump and city water. This keeps the water heater empty if you need to drain it.  
  2. 2
    Turn off any electrical and gas heating elements so it does not get ruined during this process.  
  3. 3
    Take off the cover to the water heater outside and open the pressure relief valve. This is going to get the water drained faster.  
  4. 4
    Use a 1 1/6 inch socket to get the drug plug removed. You can reuse this or pick a new one to keep it strong.  
  5. 5
    Give the water time to drain.  

If you are going to flush it out, this is the time to do it. If not, then you can put the parts back together and turn everything back on.  

People Also Ask (FAQs)

What size socket is needed to drain an RV water heater?  

For most RV water heaters, a 1 1/6 inch socket will be big enough to help get it drained out. Take a look at the drain plug to make sure that it is going to be big enough or small enough to get the work done.  

Will RV antifreeze hurt the hot water heater? 

RV antifreeze is not going to hurt the hot water tank. However, if it is left in there and it gets cold, there could be problems when you try to drain it out of the system. Just drain the water out before winter, and you will not need to use the antifreeze in the first place.  

Does the low point drain the empty water heater?

This will depend on the type of design that is in the plumbing system. Some makes and models do allow this to make things easier, while others will not. You may need to test it out to see if this works.  

How do I know if my RV water tank is full? 

You will be able to tell if the water tank is full based on the sound of the tank if you are near it. Some RVs will also have sensors placed on them to make this easier to tell.  


Draining the RV water heater is a great way to keep it safe and ensure that no bacteria or anything else will get into the system and cause a bad smell. Check out the simple steps above to help you properly drain the water tank on your RV.  

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.