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Many people wonder about the shower in a motorhome, caravan, or RV, how long you can shower with warm water until you run out, and how long you can shower in total using a full fresh water tank.
In my motorhome, I can take a warm shower with low water flow for 18 minutes and maximum water flow for 7,2 minutes. I have a warm water heater of 12L (2,6 gallons) set at 60 C (140F). And my 100 L (26 gallons) water tank would last 66 minutes at low water flow and 26 minutes at max water flow.
Here comes a table showing how long you can take a hot shower in a motorhome, RV, or caravan at 38 degrees Celsius (100 F), depending on the size of your water heater and what water flow you are using.
| water heater capacity @ 60C (140F) | *Low water flow @ 38C (100 F) | *Medium water flow @ 38C (100 F) | *Maximum water flow @ 38C (100F) |
| 10L (2.6 gallons) | 14,6 minutes | 8,8 minutes | 5,8 minutes |
| 12L (3.2 gallons) | 18 minutes | 10,8 minutes | 7,2 minutes |
| 23L (6 gallons) | 34 minutes | 20,4 minutes | 13,6 minutes |
*Low water flow is calculated at 1 Liter (0,26 gallons) per 40 seconds
*Medium water flow is calculated at 1 Liter (0,26 gallons) per 24 seconds
*Maximum water flow is calculated at 1 Liter (0,26 gallons) per 16 seconds
I made this test to see what the actual water flow in an original motorhome shower is, and this can vary quite a lot depending on what type of shower head you are using. Still, from these videos I have made, you can estimate what water flow you usually use.
In the table above, I have calculated that the fresh water tank is at 20 C (68F) and with the water heater at maximum heat, which for me with my truma water heater is 60 C (140F), so these numbers can vary depending on what temperature you set your warm water heater too and how warm your fresh water tank is or if you are connected directly to another water supply from the ground that is even colder.
The other setting I have for my warm water heater is at 40 C or 104F, which is almost the same temperature that I want to have during my warm shower, so if you use this setting on your water heater, you would need to cut the times in the table above by roughly 50%. As you notice, a big reason why the small water heaters in motorhomes last quite long is that they reach very high temperatures, so be careful not to put the tap on too warm since it is easy to get burned from too hot water.
And another factor to count on is how long it takes for the warm water heater to reheat the next batch of water. Again, I cover this question in my other article, where you will learn more about warm water heaters.
Be careful not to put the tap on too warm since it is easy to get burned from too hot water in a motorhome.
Do you use entirely different temperatures on your water heater and the cold water than I have calculated? Then you can use this link to calculate the mixture between the water temperatures and how much warm/cold water you need to reach the right shower temperature and see how long it would last.
How Long Does Motorhome (RV) Fresh Water Tank Last While Showering?
Are you wondering how long your full fresh water tank will last if you would use it all for showers? Maybe you have an on-demand water heater and want to see how long a warm shower you could take with that?
Here is a table showing how many minutes you can use your shower at different water flows and with fresh water tanks between 100L (26,4 gallons) and 300L (79,2 gallons).
| Fresh water tank capacity: | *Low water flow | *Medium water flow | *Maximum water flow |
| 100 L (26,4 gallons) | 66 minutes | 40 minutes | 26 minutes |
| 200 L (52,8 gallons) | 133 minutes | 80 minutes | 53 minutes |
| 300 L (79,2 gallons) | 200 minutes | 120 minutes | 80 minutes |
*Low water flow is calculated at 1 Liter (0,26 gallons) per 40 seconds.
*Medium water flow is calculated at 1 Liter (0,26 gallons) per 24 seconds.
*Maximum water flow is calculated at 1 Liter (0,26 gallons) per 16 seconds.
I have counted the same water flow in this table as the one above, where you also can see the videos of the different water flows.
We have a 100L (26,4 gallons) fresh water tank, and this usually lasts for four showers, cooking, and doing the dishes for 2 to 3 days. Hence, refilling the fresh water tank is one thing that limits our wild camping or boondocking trips the most unless we find a good mountain stream to stay nearby where we can refill water.
A reminder for the fresh water is that you don’t want to keep the water in the tanks for more than two weeks to keep it clean and safe, so it is suggested that you empty it if you don’t use it within that time, here is an article about how to empty the fresh water the best way And also one that covers if the water in your motorhome, RV or caravan is safe to drink.
How To Make a Motorhome, Caravan, and RV Shower Last Longer?
The best way to get longer showers in your motorhome, RV, or caravan is to lower the water flow in the shower; this can easily double your shower time. Combine low water flow with an efficient shower head and turn off the shower while putting on soap and shampoo, and you will enjoy longer showers.
As you have seen in the tables above, it will be a massive difference in how long you can shower if you use a low water flow, so this is, for me, the number one factor to save water in the motorhome to be able to shower longer or more times.
You can also look into installing an on-demand water heater but is that necessary? Isn’t it enough to have a small water heater that lasts 5,8 – 14,6 minutes, depending on the water flow? Of course, if the next person who wants to shower waits a few minutes in between, the shower will be warm and ready again, so I don’t see why it would be a good investment unless you are living full-time with hookups and have a big family that wants to take long showers all the time.
