Freshwater Tank Smell

B

bartender66

New member
We have a 2006 25 CD. When we use the water from the freshwater holding tank it smells like rotten eggs/sulphur. It is bad! We don't like to turn it on or use it. We have flushed and refilled the tank 3 times! We have our boat moored at the same marina where we kept our 22' CD. We have only filled our tank using the water at our marina which is fine, no odor or smell. The marina water is good. I started suspecting that the factory had plumbed the boat wrong. I contacted them and was told that the head and sink plumbing were two separate systems which is what I would hope be the case. We had no problems with the water on the 22'. Has anyone else experienced this problem? Thanks!
 
I have a 25 and have not experienced anything like what your are describing. I just last week for the first time in the year that we have had the boat, added bleach to the tank, run water through the system and let it sit for an hour or two and then pumped the tank dry and refilled. I think this should be on everyones check list at least yearly or more. That should disinfect the whole system.
Bleach only need a contact time of several minutes to do its germ killing thing. I used a teaspoon per gallon.
 
Anna Leigh":3dpo62wv said:
I have a 25 and have not experienced anything like what your are describing. I just last week for the first time in the year that we have had the boat, added bleach to the tank, run water through the system and let it sit for an hour or two and then pumped the tank dry and refilled. I think this should be on everyones check list at least yearly or more. That should disinfect the whole system.
Bleach only need a contact time of several minutes to do its germ killing thing. I used a teaspoon per gallon.
Click to expand...

The RV department at Wally World has a water purefier in a little bottle that can be used as well as the annual or semi annual flush as suggested by "Anna Leigh". Use per directions.

Without tracing your lines to verify the plumbing, theres not much else to do. If the plumbing was mixed up, I doubt there would only be a sulfer smell, it'd probably be much worse.

Try draining and filling the tank at another source other than the Marina if possible. Maybe they have done something different than before.
 
Also, after the bleach flushing, you can put a bit of baking powder in the water as you fill - that will help eliminate the bleach smell. No smell on ours (with all of 5 days now). A skanky dock hose could be suspect. On a lake we used to frequent, you couldn't stand to put their fresh water in a tank... smelled like old socks. Try putting some of that water from the hose into a water jug and see if you get any smell - may help determine the source. HTH

Best wishes,
Jim B.
 
If you have a hot water heater installed, it can build up hydrogen gas when it hasn't been used for a while. My 5th wheel used to do the same thing. I always made sure the pilots were off and flushed the hot water system for a while before firing it up.
 
Heavens forbid, but if you can't isolate the source and think your two systems might just be cross-plumbed, you could flush them both out, then refill the water system and then flush several of those dye pellets they use to detect leaks in toilet tanks into the head. Blue tap water would bring the bad news that ...........................

The above would show a liquid cross over, but wouldn't show an air vent cross-over. For that, you might have to use something like oil of wintergreen that would definitely cross through an air connection, but not be dangerous or unplesant.

Joe.
 
As Roy and Lucky relate, the hot water heater is usually the culprit on Sulphur smell. You can never 'reheat' a tank without increasing the Sulphur smell here in the Midwest. We drain our motorhome hot water heater everytime we go out again - even if it is only a week or two. It is an easy task if you just turn on the hot water tap. I think it helps keep the lines and drains fresher by using them more in this way also.

So, I am voting for re-heating as the culprit based on my experience. John
 
I've got the sulphur smell in the fresh water. I have completely flushed the hot water heater three or four times by turning on the water pressure and opening the heater drain. I've then run full tanks of water through. I've flushed the cold side as well, and the smell seemed to have gone away. But it's back. Today the water coming through both the hot and cold taps has the smell. I have not used the hot water heater at all. Aside from the possibility of the dock hose being bad - any other possibilites come to mind?
 
If you have the rotten egg smell, you have to shock the fresh water system with chlorox. It may be necessary to do this every few months.

Chlorine does not last long in water and if there are underlying problems the bacteria/algae will grow when the chlorine is gone.

The newer boats do use fresh water in the heads--but there is little chance to back contamination.--and it is just a "flush"--even if the sea/raw water is used on a head, there is no way that it can get into the fresh water system.
 
Anode rods are installed on top of the water heater. Look for a large hex nut near the water lines. If not present then it does not have one or at another location. First, I would check the operating manual for the parts diagram. The anode rod is attached to the nut and hangs inside the tank. The length varies but for this discussion assume it is 2 foot long but some at up to 4' long. Turn water off and use a long box end wrench to gently remove the nut. I bet you dollars to donuts that the nut does not have any teflon tape or pipe compound on the threads and might be rusted in place. Be careful with the wrench b/c you might twist the water lines b/c a water tank is usually free standing but maybe in a marine application will have braces or SS bands to secure it. After removing the rod and most of it is gone then install a new one.
 
Lucky Day,

I don't know how the Hot water heater's anode could make the sulphur smell.

From many decades of camping and boating, it has been my experience that reheating water increases any sulphur odor. It is best to run the hot water out after each camping/boating session. Some areas have more sulphur in the water than others, which could be a factor. Some bacteria increase the detectable sulphur - maybe that is the cold water problem.

I think you ought to put about 1/3 cup of clorox bleach in every 30 gallons of water all the time, not just now and then. Fill the supply tank and let it sit for an hour or so, then fill the hot water tank and let it sit forever. You can buy water sweeteners, but all the old salts on my docks say just go with Chlorine bleach - all the time - each fill, and run the hot water out if you're leaving the boat for an extended time. You can leave fresh, chlorine bleach water filling the hot water tank, but you want to avoid re-heating the same water over and over. That increases the smell.

John
 
Thanks for all of this input. I used Clorox a few months ago and will redo the flush with bleach. I am definitely going to confirm whether or not the dock water has any odor to it. My understanding is that the dock water is municipal fresh water, but I will check it directly for smell, and the hose as well. As for the hot water heater itself - I have never used it. It was checked during the pre-purchase survey in October of 2006 and worked properly, but has not even had the power switched on since then. I'm going to run down all of the leads you all have offered and see what the result is. Probably will be over this next weekend, and then I'll post the result.
 
Dr John
You are correct. The anode protects the tank for corrosive and rusting out. If the anode rod is bad and the water quality has high mineral content and salt, this can cause odors in the water.
 
Another possiblity is entrapment but you will need to know how the water system was plumbed. If bad water is trapped in the system, it is difficult to remove by cleaning, flushing and draining. It is still trapped and the plumbing will be to redone. This occurs in city water supply sytems. for example An end pipe with poor or none water cirulation and low water pressure will cause bacteria to grow and produce large amounts of slime and odor b/c the chlorine levels are low and poor circulation. To resolve the problem then the water line needs to be repaire.
 
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