Stale RV Water Solutions
Take care of your RV water system and in return it will provide you with many years of reliable service. The potable water system in your house is pretty much maintenance free. The potable water system in your RV, on the other hand, requires some maintenance to keep it trouble free. Something I’ve run into quite often is the complaint that there is a stale odor coming from the RV water system. When you return from a trip and you’re not going to use the RV for a while you need to drain the entire water system to prevent it from getting stale and musty.
You can start by draining the water heater tank. Go to the outside compartment where the water heater is located. The drain plug, or petcock is normally located in the bottom left hand corner. Remove the plug and open the pressure relief valve on top of the water heater to assist in draining.
Caution: Never drain the water heater tank when it is hot or under pressure. Turn off any water source going to the RV(i.e., city water, water pump). Open a hot and cold water faucet to relieve the pressure. Allow the water in the tank sufficient time to cool before draining.
If you have a suburban water heater it will have an anode rod. The anode rod is designed to help prevent corrosion in a suburban steel water heater tank. Corrosive elements in the water will attack the rod rather than the tank. Inspect the anode rod every time you remove it to drain the tank and replace it when approximately ¾ of the rod is consumed. Atwood water tanks do not require an anode rod, and use a nylon drain plug because the tank is made of aluminum.
Next you need to locate the low point water line drains. It may take a while to find them, but I assure you they are there. There will be one for the hot and one for the cold water lines. This is the lowest point in the water system. Open these and let the water drain out. There’s one more thing left to do; find the drain for the fresh water holding tank and drain all of the water from it. At this point you can turn the water pump on for a moment to force any remaining water out. Do not let the pump continue to run once the water stops draining. Close all of the drains.
If by accident you forget to drain the water system and you get that notorious stale odor all is not lost. You just need to sanitize the water system.
* Start by draining all of the old water out of the system, and then close all of the drains.
* Take a quarter cup of house hold bleach for every fifteen gallons of water that your fresh water tank holds. Mix the bleach into a one-gallon container filled with water and pour it into the fresh water holding tank.
* Fill the fresh water tank completely full of water.
* Turn the water pump on, open all hot and cold faucets and run the water until you smell the bleach at each faucet.
* Close the faucets and let it sit for about 12 hours. Note: If it’s possible drive the RV or pull the trailer so the water can move around to assist in cleaning the entire tank.
* Drain the entire system and re-fill the fresh water tank with water.
* Open all of the faucets and run the water until you no longer smell any bleach. It may be necessary to repeat this process again to eliminate all signs of bleach from the water system.
Once this is done it is safe to use your water system. It’s also a good idea to use a water filter at campgrounds and to keep bottled water on hand for drinking.
To learn more about maintaining your RV check out our RV Care & Maintenance DVD
Happy Camping,
Mark Polk





Your comment about low point drains is incorrect. Not all RVs have low point drains.
Somewhat as a spin off of the issue of keeping water fresh I have a question. Always heard the only dumb question was the question not asked?
So many times I have been in various camp sites which had terrible tasting water that we so often carry our own water for ice, coffee, drinking, etc. If one used the potable tank to carry good water from home once hooked up on camp system water, I presume the camp system is your main flow of water even if you turned on the water pump? Is that true or does the water pump over-ride the camp water inlet?
You would always have to run enough out of the camp system to get to the potable water if probably wouldn’t be worth the effort?
Just wondering?
Jim,
I guess I could have said 99% of RV’s have low point water drains. I can’t recall seeing any without them, but I’m sure there are some around.
GlenO,
You should use one or the other, but not both. We alway fill our fresh water tank at home before we leave on a trip. If we do connect to a water source it is filtered before it comes into the RV. And we almost always have bottled water on hand too. If in doubt about the water source use the potable water in the fresh water tank.
don’t believe you should use your pump when
your hooked up to outside source of water……..city, campground
or whatever.
Another silly question. How do you figure out the number of gallons your tank holds? I bought my RV second hand and it doesn’t have any manuals. Thanks guys…
Sue,
Its not a silly question and there is no easy answer.
1) If the RV is fairly new try going to the manufacturers website and look for a brochure on the model you have. The specifications normally tell the size of the fresh water, black & gray water holding tanks.
2) If that doesn’t work try calling an RV dealer that sells the brand of RV you have. Many salespeople keep brochures on file for previous year models.
3) Go to the RV forum for the type RV you have and ask if anybody else has the same year and model with the information you are requesting.
4) Possibly the least favorite method would be to fill the water tank, when it is empty, using a 2-gallon bucket and large funnel. Most monitor panels register the tanks contents in thirds i.e.,, 1/3, 2/3, full. Fill the tank until it reaches 1/3 (or whatever increment yours measures in) and then do the math based on how many gallons it took to get to 1/3. This certainly isn’t full proof, but it will get you in the ballpark.
5) If your water tank is easily accessible, measure the length, width, and height in inches. Multiply length times width times height. Divide this product by 231 and the result is in gallons. be sure to keep all measurements in inches. (231 cubic inches =1 gallon)
If your tank is not a neat rectangle, it will be very difficult to measure it this way.
6) Or, if this method is practical for your particular setup, you could fill the tank and drain it into a 5 gallon bucket, emptying each time it fills, (or other convenient known size) and keep track of how many times you emptied the bucket while emptying the tank.
I always put a little bleach in my tank, between trips, and drain it before we leave so I can fill with fresh water. I would like to run some of that bleachy water through my faucets but afraid some of it may get in my expensive inline water filter and I would never get the taste out (unless I buy another filter). Do you think it’s safe to run the bleach through the filter?
Mark, I know you said to drain the water from the holding tank but, how long can you safely leave water in your holding tank. I also use a product to help keep the water from getting stale i believe it is called pure water and is sold at most RV dealers and Wal-Mart, is this safe to use and will it allow you to keep the water in the holding tank longer.
Randy A.
Mark, One final question regarding water systems. We have an Everpure filter at the kitchen sink and wonder if the element needs changing after circulating chlorine? Very expensive proposition. thanks, Jim
Len & Jim,
I would remove the water filter (place iot in a plastic bag) when I sanitize the water system. After the system is flushed out reinstall the filter.
Randy,
I’m sure that products like Pure Water are safe to use and that they do what they advertise they do.
I don’t know exactly how long water can be left in the system before you experience problems. If we have a trip planned 2 or 3 weeks after returning from a trip I leave the water in the RV. If it’s going to sit for a moth or longer I drain it.
I think the majority of water related problems occur from letting water sit in the unit during long term storage. One problem with many RV’s is that even when you drain the fresh water tank there is still a litlle water remaining because of where the drain is located in relation to the bottom of the tank. This little bit of water (moisture) in the tank gets musty and stale over time and eventually causes a foul odor.
The same is true with the water heater tank. You can drain it but not get all the water and sediment out of the bottom of the tank. That’s why you should periodically flush the water heater tank. Check out this video clip for more info. http://rveducation101.com/videostream/?clip=Water_Heater_Maintenance
[...] Stale RV Water Solutions: You can prevent those notorious musty odors in your RV’s potable water system by taking a [...]
I get a rotten egg smell ONLY when I open the HOT water tap in the bathroom lavatory. No other tap has this odor, i.e., the lavatory cold water tap and the hot and cold water taps for the shower and kitchen have no odor. Please tell me what I can do to eliminate this problem. Thanks.
I have the rotten egg smell with both hot and cold water. It is the kitchen sink, the shower and the lavatory sink.
We do not store any water in the fresh water holding tank.
Is the solution still with the hot water heater needing to be drained and cleaned, or is there something else?
Thanks!
Opening the pressure relief valve to drain the hot water heater is a sure way to create a leaky pressure relief valve. Been there, done that!
Why all this bottled water? All public water is tested and certified by the water companies, not so for bottled water. I drink it all the time but I do drain before leaving camp every trip and refill after I get where I’m going. At 8lbs per gallon all that weight really costs to haul around.
I was hooked up to city water when I lost pressure. I disconnected from the scource and the check valve was bad. Hot water backflowed out of the input . I replaced the check valve but still get no water pressure. The water pump works fine and I can get water pressure with the pump but not from the city hook up. Can you shed some light on this? thanks, Robert