Smelly Hot Water

[Robert Mann]

Other than the hot water I'm normally in, the variety on the boat has a distinct, unpleasant odor since being refilled after the winter.  The cold side is fine but the hot smells like H2S.

I traced another thread that discusses changing the element, but I have a hard time thinking this is the cause.

Has anyone nailed down the reason?  Could it be growth or mold in the lines reacting with heat?  Is it caused by the potable anti freeze I used over the winter?  Will a simple bleach attack on the  system cure the problem?

Any input welcomed.

[Jeff Kaplan]

bob, end of last season i completely emptied both tanks. prior to refilling this season, i filled the aft tank with about 5 gals. and added a gal of bleach. turned on the pump, opened all faucets and ran till water came out of each. shut off pump and let solution sit over night. drained all water and refilled with fresh. smell gone. try the easy approach first to see if this corrects the problem...jeff

[Rick Johnson]

Damn, I have the same issue and never thought to ask.  It always seems worse when the water has been sitting in the tank for awhile.  Once I start using the hot water the smell quickly disappears.  I would love to know a solution or at least what causes this.  My water heater is only about a year old.

Cheers

[RV61]

I add a cap of beach with every fill of the tanks to keep the bacteria that is causes odors at bay. Have not had any problems since. 

[Stu Jackson]

Part of the answer is to get into the habit of using the hot water faucet ALL THE TIME. 

This continues to move the water through the heater all the time, and avoids having anything drop out of the water, onto the element and create a stink.  If the water is cold (heater hasn't been heated up by element or engine) it doesn't matter, right? -- you get cold water from either tap.  If the water is hot, then start with the hot water and adjust the cold.  Some argue that this uses up more hot water, but either get really quick about it, or start the cold faucet first then the hot if the heater is hot.

I learned this from reading the tech notes.

[Jeff_McKinney]

What is the source of your water? The H2S may be dissolved in the water at a low concentration and not noticeable when cold, but when you heat it up the stuff is liberated as a gas.  

The latest issue of Sail Magazine just had a quick article on sanitizing the H2O system. Don't forget to rinse out any anitfreeze first, and get BOTH tanks treated. They recommended a similar approach to Jeff's, but say keep the contact time with high concentration solution at about 8 hours. Flush it out with plain water until it doesn't smell like bleach, then add 1/2 oz of bleach per 5 gallons of water & fill it up.

Good luck.

[Robert Mann]

Thanks guys, I will head into the Memorial Day weekend with a gallon of bleach and give the tank a good treatment.  Seems logical.

To answer Jeffs question, the water comes from the dock side supply which is normal city water.  This is first time I have noticed the problem, so while not being 100% sure, i don't think it's a problem of water borne H2S.

[Stu Jackson]

WATER TREATMENT FOR BOATS

This is regularly re-posted by Peggie Hall on the www.catalinaowners.com website.  I copied it for my own files and reprint it here.  Evidently, adding a little bit'o'bleach everytime isn't the appropriate thing to do.  Read on...

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Title: Recommission the system at least annually

"This is all it takes to keep onboard water safe, and tasting/smelling as good as any that comes out of faucets on land: Fresh water system problems--foul odor or taste--are typically caused by allowing water to stagnate in the system. Although most people think only in terms of the tank, the plumbing is actually the source of most foul water, because the molds, mildew, fungi and bacteria which cause it thrive in damp dark places, not under water. Many people—and even some boat manufacturers—believe that keeping the tanks empty reduce the problem, but an empty water tank only provides another damp dark home for those "critters."   There are all kinds of products sold that claim to keep onboard water fresh, but all that's really necessary is an annual or in especially warm climates, semi-annual recommissioning of the entire system—tank and plumbing.

The following recommendations conform to section 10.8 in the A-1 192 code covering electrical, plumbing, and heating of recreational vehicles. The solution is approved and recommended by competent health officials.  It may be used in a new system a used one that has not been used for a period of time, or one that may have been contaminated. Before beginning, turn off hot water heater at the breaker; do not turn it on again until the entire recommissioning is complete.  Icemakers should be left running to allow cleaning out of the water feed line; however the first two buckets of ice—the bucket generated during recommissioning and the first bucketful afterward--should be discarded.

1. Prepare a chlorine solution using one gallon of water and 1/2 cup (4 oz) Clorox or Purex household bleach (5% sodium Hypochlorite solution ). With tank empty, pour chlorine solution into tank. Use one gallon of solution for each 5 gallons of tank capacity.
2. Complete filling of tank with fresh water. Open each faucet and drain cock until air has been released and the entire system is filled.  Do not turn off the pump; it must remain on to keep the system pressurized and the solution in the lines
3. Allow to stand for at least three hours, but no longer than 24 hours. 4. Drain through every faucet on the boat (and if you haven't done this in a while, it's a good idea to remove any diffusion screens from the faucets, because what's likely to come out will clog them). Fill the tank again with fresh water only, drain again through every faucet on the boat.
5. To remove excess chlorine taste or odor which might remain, prepare a solution of one quart white vinegar to five gallons water and allow this solution to agitate in tank for several days by vehicle motion.
6. Drain tank again through every faucet, and flush the lines again by fill the tank 1/4-1/2 full and again flushing with potable water.

People have expressed concern about using this method to recommission aluminum tanks. While bleach (chlorine) IS corrosive, it's effects are cumulative.  So the effect of an annual or semi-annual "shock treatment" is negligible compared to the cumulative effect of holding chlorinated city water in the tank for years. Nevertheless, it's a good idea to mix the total amount of bleach in a few gallons of water before putting it into either a stainless or aluminum tank. People have also expressed concern about the potential damage to rubber and neoprene water pump parts. Again—the cumulative effect of carrying chlorinated water is far more damaging over time than the occasional "shock treatment." And it's that cumulative effect that makes it a VERY bad idea to add a little bleach to each fill.  Not only does it damage the system, but unless you add enough to make your water taste and smell like a laundry, it's not enough to do any good.  Even if it were, any "purifying" properties in chlorine evaporate within 24 hours, leaving behind only the corrosive properties.

An annual or semi-annual recommissioning according to the above directions is all that should be necessary to keep your water tasting and smelling as good as anything that comes out of any faucet on land.  If you need to improve on that, install a water filter. Just remember that a filter is not a substitute for cleaning out the system, and that filters require regular inspection and cleaning or replacement. To keep the water system cleaner longer, use your fresh water...keep water flowing through system. The molds, fungi, and bacteria only start to grow in hoses that aren't being used.

Before filling the tank each time, always let the dock water run for at least 15 minutes first...the same critters that like the lines on your boat LOVE the dock supply line and your hose that sit in the warm sun, and you certainly don't want to transfer water that's been sitting in the dock supply line to your boat's system. So let the water run long enough to flush out all the water that's been standing in them so that what goes into your boat is coming straight from the water main.

Finally, while the molds, fungi and bacteria in onboard water systems here in the US may not be pleasant, we're dealing only with aesthetics...water purity isn't an issue here--or in most developed nations...the water supply has already been purified (unless you're using well-water). However, when cruising out of the country, it's a good idea to know what you're putting in your tanks...and if you're in any doubt, boil all water that's to be drunk or used to wash dishes, and/or treat each tankful to purify. It's even more important in these areas to let the water run before putting it in the tank, because any harmful bacteria will REALLY proliferate in water hoses left sitting on the dock. "

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[Ron Hill]

Guys : Be careful about using too much bleach.  A cap full per 25 gal should do the job.
Here are some other thoughts on eliminating smelly water:
1.  I filter the water BEFORE it goes into the tank thur a filter I made that attachs to a hose.
2.  If you have the head water hoses pop up in the engine compartment, reroute them as I mentioned in a Mainsheet article.
3.  When I rerouted the hoses from going thru the engine compartment, I also changed to a different type of hose - same Mainsheet article.
A few thoughts - I now have NO smelly water coming out of APACHE's faucets!! 

[Fred Jackson]

Robert,

Avoid heating the hot water tank when it has even traces of antifreeze in it.  Before I start my engine in the spring, I flush the hot water tank out thoroughly.  I found in the past that if I have heated antifreeze in the water tank it takes a long time for the odor to go away.

Fred J.
Amante Catalina 36 #2209

[Robert Mann]

Drained the tank, refilled, after letting the hose run for 10 minutes and added 4 pints of Clorox bleach.
Ran water from all faucets and the shower until bleach solution was coming through. Pressurized the system with the water pumps and then we let the system stand for almost 5 hours.  Drained the system, flushed one tank of clean water through the system and then refilled.  The water still has a slight bleach flavor but it's a vast improvement with no bad taste even when the water heater has been working all night.