Water Heater has a strange odor

J

jmicklov

Member
Joined
Dec 23, 2004
RO Number
15952
Messages
188
Noticed a very strange odor when I ran my hot water faucet. At first I thought it was the basic fresh water holding tank. I put a little chlorine into the fresh water holding tank. This is also the second or third time I've filled up the tank, so any antifreeze is long gone.

When I ran the water today, the cold water had a very faint trace of chlorine odor, which you would expect. When I ran the hot water, which was still warm from the preceding days' trip, it did have a noticeably different odor to it.

Before I added chlorine to the fresh water tank, the odor from the water heater was pretty nasty. Hard to describe.

How do you determine if the water heater is destined for water heater heaven? Is there something that fails in the water heater that generates these nasty odors?
 
Has the water in the hot water tank been there for a long time? Mine will get a stagnant smell during the heat of summer if I miss a weekend at the boat and don't run water out of the tank.
 
It's likely the anode in the tank, most of them have a way to get them out on the top of the tank. The ones I've seen are a six sided bolt like fitting.
 
Rotten onion smell? Comes from using RV anti-freeze in heater over the winter. Never use AF in water heater. The anode, as mentioned, is shot. Some can be replaced--some, like mine (Sealand), can not.
 
When I bought my Silverton they had a recall on water heaters going on. Even though my boat was a 1986 they still included me in the recall and sent me a new water heater. When I had the marina install it, also paid for by Silverton, they suggested a bypass kit on the water to the heater so it would not get antifreeze into it during winterization. I did that and it saves you from filling that tank with antifreeze and yes of course the smell and taste of it.
 
The first time I noticed a foul smell was after the boat sat out of the water for about 3 weeks, during which time the water system wasn't used at all. It was also quite hot during that period. I'm on my first new tank of water after that and the smell is not as strong. So, Planeguy- you might be right. Just stagnant water and since the hot water is not used as much, it could be much more pronounced there.

It's definitely not antifreeze. At the beginning of the season, I flush out the water system to get the antifreeze out of it.

What I might try as a process of elimination is to simply drain the hot water tank into the bilge and then turn on the water and refill the hot water tank. If the odor persists, it could be the anode. Is this where the anode material breaks down and goes into the water?
 
I filter my water before I put it on the boat; seems to take care of the problem.
 
I know bad anodes and antifreez can be a problem. But I think a more common problem is simply bacteria in the lines. It can cause some pretty rank smells. I have found that any mal-oder I've had in my water is cured if I put a heavy dose of clorine into the holding tank. Let it sit a day, then run that water thru all of my fixtures and let that sit a day. I follow that up with flushing 20-40 gallons of fresh thru. That has always taken care of it. But it can still come back if the water sits in your lines for a week or two between uses. But the above is worth a try before replacing the water heater.
 
happens on my boat when i go on a trip for more than a couple of weeks... all it takes is running hot water for a while to thoroughly flush the water heater and it goes away.

now, i turn off the water heater and run the hot water to flush it before leaving, it helps.

i've never had to put anything in my water tanks since i use them a lot. city water has some chlorine in it and that seems to keep the tanks clean since i refill them every 4 to 6 days or so.
 
I've already put chlorine into the fresh water tank. And that has helped the cold water odor. So, I'll flush the hot water tank completely and let the new chlorine laden water replace it and then run that through the lines.

Thanks for the great suggestions.
 
I have the same problem at our lake house, I used to turn the hot water heater off when we were away. This isn't a problem in the winter when it is cool/cold in the crawlspace. In the summer, though, the temp is just right for all kinds of "stuff" to grow in the water, after two or three weeks away it would reall stink when I turned it back on. Now, during the summer I leave the hot water heater on, keeps the water too hot for stuff to grow and in the winter off - too cold for stuff to grow. I would think on a boat I would not want to leave the heater on, so flushing it might be the way to go. I doubt if it's the anode.
 
Install the bypass kit mentioned above or just disconnect the lines and drain the water heater when winterizing. Open the drain valve and the TP valve so air can get into the tank and water can drain. Don't forget to close both before spring filling. You won't be putting antifreeze into the water heater tank.

Turn the electric power off and tag it. You will burn out the element in a minute or so with no water in the tank.

If your hot water smells bad, flush the tank a few times (with the electric power turned off), see if that corrects the problem.

Adding excessive chlorine to the system and leaving it for more than a few hours will cause more problems than it solves. You can add it, run it through all the plumbing and fixtures, and let it sit for a couple hours. After that, you must drain and flush all the tanks, lines, and fixtures.

Use only clean water from a known good source to fill your water system. Use only "a drinking water safe" hose that's used for nothing else and not left around the dock for others to rinse their holding tanks with. If you fill your tank with untreated well water, adding a small amount of chlorine (unscented laundry bleach) is a good idea. A "guess" would be a couple tablespoons for twenty gallons. You can find a more accurate ratio on the Internet somewhere. If you can barely smell it, it's about right and equal to treated city water.

The anode can cause the water to smell if water sits in the tank for a long time. Drain and flush the tank as above. If the problem persists, it's time for a new anode or a new tank. In many cases, by the time you remove the heater to get to the anode, you are better off replacing the tank and starting out fresh. They don't last forever.
 
Before I was getting ready to drain the water heater, figured I'd run both hot and cold faucets first and see what it was like. Smell was gone in both hot and cold faucets both in the galley and head sinks. You can detect a very faint odor of chlorine (I also have a very sensitive nose), so based on what you're saying, should be about the right level. So, I think the culprit was the stagnant water in the water heater when the boat was out for 3 weeks.

Don't have much choice in water sources. Dock is fed from a city source and through garden hoses along the dock, for hundreds of feet. And sitting in direct sunlight, the water can be quite hot when initially turned on. Now, I need to make sure it runs for a while to get cooler, before using it to fill tanks.

Again, many thanks for your thoughts and suggestions.
 
quote:
Originally posted by jmicklov

Before I was getting ready to drain the water heater, figured I'd run both hot and cold faucets first and see what it was like. Smell was gone in both hot and cold faucets both in the galley and head sinks. You can detect a very faint odor of chlorine (I also have a very sensitive nose), so based on what you're saying, should be about the right level. So, I think the culprit was the stagnant water in the water heater when the boat was out for 3 weeks.

Don't have much choice in water sources. Dock is fed from a city source and through garden hoses along the dock, for hundreds of feet. And sitting in direct sunlight, the water can be quite hot when initially turned on. Now, I need to make sure it runs for a while to get cooler, before using it to fill tanks.

Again, many thanks for your thoughts and suggestions.
Click to expand...


My dock water is hot also and I let it run to cool it but it's in plastic water pipe, not garden hoses. I never checked how it gets to the floating dock, If I remember, I'll check the next time I'm there.

"They" say chemicals in standard hoses can leach out into the water and harm humans. I couldn't prove it, but if you don't have to take the risk, it's better not to.

I've never had a problem from leaving water in the tanks or heater but that doesn't mean someone else won't.
 
Everybody who's replied so far is basically correct. It can be any (or all) of the things mentioned up until now. Some water heaters have a glass-clad steel tank. Just about all of these have a magnesium anode rod in them. The anode rods all have an iron core. As the anode is eaten away by chemicals in the water, stray electrical current, or whatever, the iron core eventually becomes exposed to the water. Some sort of chemical action takes place between the water, the magnesium, and the iron, which gives the hot water a "rotten egg" smell.

If your water heater has a glass-clad steel tank, and you're getting that smell from the hot water, it means that the anode should've been replaced last season. Rule of thumb, the anode should be checked annually, usually during spring commissioning. If there is less than 50% of the original metal left on the anode, put a new one in! That way, you'll stay ahead of the stinky water problem.

Once the problem develops, it isn't just a matter of changing out the anode and the problem will go away. The water heater must have it's electrical power turned off, then it must have all its plumbing disconnected, the tank drained, and clean water added via a garden hose, until all the cloudy-looking water stops draining out of it - it must be completely flushed out. Then, the new anode is installed, and the water heater put back into service. Just be sure it has been filled with water, the pressure pump has come up to pressure and shut off, before turning on the electric power to it.

On Raritan water heaters, the anode is the actual hot water "out" nipple that came with the water heater when it left the factory. This must be removed, if you push the plastic finish washer in, toward the center of the tank, you'll see an area on the nipple that has no threads. A small pipe wrench can be put on it there, and the nipple unscrewed from the tank. The new nipple/anode assembly is screwed in - you'll note that you need about a foot of clearance outside the water heater in order to jockey it into position, and then screw it in.
 
Vic- Thanks for your input.

I'm going to pull out the documentation on the water heater now. Not sure what can or can't be accessed or replaced. I seldom heat the water using shore power, as most of the time whenever I need hot water, it's been during/after running a while and the engine coolant that circulates heats up the water. But that's not to say everything is cool either.

Also plan to re-check the water in another day or so. The last time, it was definitely improving, with just a touch of chlorine smell, but nothing else. Hopefully it will not have changed and I can at least get through the remainder of this season.
 
had same issue however mine turned out to be heat exchanger went bad and smell only when engine running
 
You must log in or register to reply here.
Back
Top