Jump to content

Smell in Hot Water

Recommended Posts

We have a 2021 Coachmen Leprechaun 311FS and we are hooked to city water. They had a break in the water line some place and the water was colored and you could tell that they were killing bacteria and the like because the chlorine smell was strong. That is all cleared up but now when we turn on the hot water we get a smell, it is not a Sulphur or rotten egg smell it is something different. We have a Dometic WH6-GEA Gas/Electric water heater and there is no anode as I was thinking maybe it is smelling.


Thanks in advance for all your replies.

Link to comment
Share on other sites

4 hours ago, Darryl&Rita said:

Dometic water heaters have an aluminum tank, and don't use anode rods. Otherwise, good information.

Absolutely. There are algae varieties that only grow in hot water that are notorious for that rotten eggs smell in hot water. It it were me, I'd do a full water system sanitization since you know that you probably had some bad water. 

Link to comment
Share on other sites

Get one of these. This is from Walmart, but there's many places to get one from. Turn off the water heater, and let it cool. Turn off the water pump, or faucet, and release the pressure in the system. Remove the drain plug. Connect the flusher to a garden hose, while the tank is draining. Turn on the water to the flusher, and insert into the drain hole. Move the nozzle around, side to side, and in and out. Keep an eye on the white chunks coming out. That's what you're trying to get rid of. When they stop, and you don't hear anything bouncing around in the tank, you're done. Reverse all the above. Enjoy.


Link to comment
Share on other sites

5 hours ago, Darryl&Rita said:

Get one of these. This is from Walmart, but there's many places to get one from. Turn off the water heater, and let it cool. Turn off the water pump, or faucet, and release the pressure in the system. Remove the drain plug. Connect the flusher to a garden hose, while the tank is draining. Turn on the water to the flusher, and insert into the drain hole. Move the nozzle around, side to side, and in and out. Keep an eye on the white chunks coming out. That's what you're trying to get rid of. When they stop, and you don't hear anything bouncing around in the tank, you're done. Reverse all the above. Enjoy.


Thanks D&R


Link to comment
Share on other sites

It takes a long time for the odor to leave. I stayed at a place in South Florida that had the "Iron Oxide" odor in the hot water. Cold water had no odor, but I wouldn't drink it. The house on the property had huge filters and a water softener I had filters but not the softener on the first stay. The second time I did and it worked for a bit, but then no matter how many times I "activated" the softener or changed the filters, there still was an odor when I showered. Thankfully it doesn't remain long enough for anyone to notice and I don't believe it's harmful. I would flush my water heater at least monthly, but usually every couple weeks while I stayed there. I only filled my fresh water holding tank once and then let it drain without going through the pump once I started noticing the odor. 

I took samples to a couple water companies in the area and they found only high iron content, which they said was typical in the area and "Would you like a water softener to take it out?", "Sorry we don't have anything for a RV. "


Good luck with it getting better, thankfully we can move. 



Link to comment
Share on other sites

This will stir up the hornet nest. I used to be in the water treatment business for 20 years   A large portion of my area had iron in the water.  There are a lot of different systems that help with odor. After putting in systems that help a lot of times we would remove the anode rod to get the odor gone. And no I never saw tank failures.

Link to comment
Share on other sites

I use household white vinegar to descale my Custom High Dollar Walmart Tea Kettle from time to time. I put some in it, warm it on the stove, and apply the principle of leave 'er.  Rinse. Looks like new. 

Is household white vinegar ok to use to descale the water heater tank? 

I was thinking I could flood the tank with vinegar via the winterizing kit intake, heat it up a bit not to full blast, then let it stand, repeat the warming process a couple times over a 24 hour period? 


Link to comment
Share on other sites

Hydrogen Sulfide gas is the rotten egg odor. We even emit it ourselves sometimes, depending on our diet.

The only way I used to get rid of it, and it's gone that day, is to move to another area with a different water supply preferably chlorinated city water, and thoroughly flush your system with good water, and then sanitize with bleach. 

Unless you live in your RV stationary all of us will pick this harmless bacterial bloom from some safe well water supplies that have the bacteria, iron and/or sulphur in the water. It is not harmful just stinky. Bleach is not the only the only solution. (pun) You can use Peroxide as below. Unfortunately our winter quarters when we were full-time RVing was a 12 acre family property with rentals and one RV pad with full hookups we set up with a slab. It had iron and the iron/sulfate reducing bacteria.

We tried shocking the well with bleach as we were advised but all that did was to make the water unfit to shower with, the bleach was so strong.

Nothing would fix it as long as we used our well, until we got to another water supply on our way out for the year's travels. We had an RV park off I-20 we stopped at every year for their sweet water to sanitize with and to fill up our fresh water tank. 

So if you want to use the tried and true way, here is a basic video, and a link for more complicated RV water systems.do a search here on sanitizing your fresh water supply with bleach in these forums for directions. Then wait until you move to another place with different water so you aren't just starting a bacterial bloom again. Here's a short video on how: 


Here's the YouTube page with more videos on sanitizing your RV if yours looks different: https://www.youtube.com/results?search_query=Sanitizing+RV+Fresh+water+with+bleach 

I used a double water filter system of two whole house filters joined with a 4" brass nipple between them and a male 3/4 to hose adapter at one end and a 3/4" to female hose adapter at the other. I used a pressure regulator at the faucet, then the hose to the RV, and the two filters, a sediment first and the second with a charcoal filter to take out the chlorine and taste. The filter canisters would get slimy a bit too so instead of messing with valves I would put the bleach and water mixture into the first and second canisters without filters to clean them too, as well as the length of hose from the filters to the rig city water inlet.

Just remember where you took on the "bad" water. Flush and sanitize from another water source so you don't take on the bacteria again.

What causes it?


"Depending on your water source, your water will contain various amounts naturally occurring sulfur. Your water probably also contains naturally occurring sulfate-reducing bacteria. These organisms are harmless to humans, and if you’re on city-treated water, most are killed (along with any harmful bacteria) when your city adds chlorine to the water. But if you’re using well water (which isn’t chorlinated), more of those naturally occurring organisms are in your water, and your water might also contain higher concentrations of sulfur.

If you check the section of Wikipedia’s article on sulfate-reducing bacteria titled “Problems caused by sulfate-reducing bacteria,” it says:

sulfate-reducing bacteria can create problems when metal structures are exposed to sulfate-containing water: Interaction of water and metal creates a layer of molecular hydrogen on the metal surface; sulfate-reducing bacteria then oxidize the hydrogen while creating hydrogen sulfide, which contributes to corrosion.

In other words, if you take sulpher, plus this bacteria, plus a corrosive metal inside your water heater, the end result is that the metal will corrode and the bacteria will create hydrogen sulfide (H2S) … which smells like rotten eggs.

If you’ve read my previous post on anode rods, you’ll recognize right away the source of your stinky water: the metal anode rod in your water heater. Your anode is most likely made of magnesium or aluminum, and it’s designed to corrode (so that your tank won’t). But when the bacteria eats away at your anode, one of the byproducts is stinky H2S gas. But read on to find out why you shouldn’t just yank that anode rod from your tank.

Things that can make the problem worse

If you use a water softener, the water softening process increases the conductivity of the water in your tank, which corrodes your anode even faster, which lets the bacteria form smelly gas more quickly. So if you have well water (which is probably hard, untreated, and has more sulfur and bacteria) and you soften it, you’re far more likely to have smelly water.

Your problem gets even worse if water doesn’t flow though your tank often, like at a cabin or vacation home. Water heaters that sit unused for weeks or months allow the H2S gas to really build up — which is actually why I started looking into how to solve this problem. Our cabin gets its water from a community well (strike one), we use a water softener (strike two), and the water in our tanks sits for weeks at a time (strike three). If it’s been a while since we’ve visited, you’ll hop out of that first shower smelling even worse than when you got in.

How can I get rid of the smell?

Depending on how bad the problem is, and how many “strikes” you’ve got against you, there are a few different things you can try to fix the smell. They all focus on either preventing the formation of the H2S gas, or killing the bacteria that’s causing it. Some plumbing “experts” might tell you to just remove the anode from your water heater. I won’t lie — that will fix the issue… but it’s a dumb idea. Removing your anode actually voids your water heater’s warranty. Why? Because removing the anode will cause premature rust and leaking! Just don’t do it.

Source for some of the above: https://www.stevejenkins.com/blog/2015/02/fix-rotten-egg-smell-in-your-water/

An even easier way to get the stuff into the heater that I use often. If you have the tank drain prepared so that you can drain a quart of water or so, this will take 5 minutes. (1) Shut off cold water intake to tank. (2) open tank drain (you will lose a bit, not much, water, until vacuum stops it). (3) fill a quart jar with however much bleach/hydro peroxide you want in tank (I use a cup or so): I dilute it 3:1 (4) duct tape a short hose section to the most convenient hot water faucet you have and put the end in the quart jar. (5) open hot water faucet-- the line will protest, then it will suck the entire contents of the jar through your system, into the heater (again the same amount of water will drain from the tank) (6) close faucet (7) close h/w tank drain and re-open inlet. (8) forget about it, and when you next use the hot water--3 hours? 8 hours? more, you'll have a tankful of chorinated water that you can use however you normally use hot water. This takes 5 minutes: if you try to drain and refill tank, which is probably better, you make this simple procedure a complicated one.

I like that idea but haven't tried it myself. It makes it easy to treat the water heater only. But if the rig has been sitting for more than a few weeks I rearrange the filters and hoses so all the hose gets exposed to the bleach. Since the bacteria breeds in the water heater tank, once I have the filter canisters empty and full of bleach solution, before I turn the water on inside the rig, I set it up to fill the fresh water tank only. Once the solution is in my full fresh water tank, I turn off the outside spigot, I turn on my water pump so the faucets only draw from the now bleach solution in the fresh water tank. I turn on the hot water faucet nearest the water heater until I smell the bleach, then turn it off, and repeat with each hot water faucet until I smell bleach including the shower. Once all the hot water faucets are done repeat with all the cold water faucets just until you smell bleach. Let it sit for four or five hours then turn on the outside park water spigot and flush the hose and empty filter canisters of bleach then replace the filters.

After four hours or so, using the valves on your water tank, drain the fresh water tank of the bleach solution, and refill with fresh water. Flush out all the faucets for a minute or two and you are ready to use a safe clean fresh water supply.

BTW I liked to close my gray valve and run about a half gray tank of the bleach solution into it using the water pump before I dump the fresh water tank to rinse. I leave that overnight to knock back the gray tank smell and all its lines and pipes.

Hope that helps.

Edited by RV_
Link to comment
Share on other sites

From the Dometic WH-6GEA Owners Manual (Page 18-19)...

Section 6.4.2 Reestablishing the Thermal Expansion Air Pocket is an important read, too.


6.4.3 Flushing the Tank
Use this procedure for general flushing of the water heater tank.
1. Turn off the main water supply (the pump or water hook up source).
2. Remove the drain plug to drain the water from the tank.
If the water drains sporadically or trickles out of the drain hole, open the P/T relief valve then use a small gauge wire or coat hanger to remove any obstructions from the drain hole.
With the tank drained, approximately two quarts of water remain at the bottom of the tank. This water contains most of the corrosive particles. To remove these particles, use an “RV Water Heater Flushing Tool.” [Darryl's suggestion above] The wand of this flushing tool allows the water jet to clean at different angles inside of the tank. Cleaning at different angles inside of the tank will suspend and flush the corrosive particles out of the drain coupling.
3. Continue flushing the tank until the water being flushed from the drain coupling is draining as clear water.
4. Replace the drain plug.
6.4.4 Flushing to Remove Unpleasant Odor
A rotten egg odor (hydrogen sulfide) may be produced when the electro-galvanic action of the cladding material releases hydrogen from the water. If sulfur is present in the water supply, the two will combine and produce an unpleasant smell.
1. Turn off the main water supply.
2. Remove the drain plug to drain the water heater tank.
3. Reinstall the drain plug.
4. Remove the P/T relief valve.
5. Mix a solution of four parts white vinegar to two parts water. [noteven & Kirk]
6. With a funnel, carefully pour the solution into the tank.
7. Cycle the Water Heater with the vinegar/water solution, letting it run under normal operation four to five times.
8. Remove the drain plug and thoroughly drain all of the water from the tank.
9. Flush the Water Heater to remove any sediment.
You may flush the tank with air pressure or fresh water. Pressure may be applied through either the inlet or outlet valves on the rear of the tank or through the P/T relief valve coupling located on the front of the unit. If flushing through the P/T relief valve, lift the handle and apply the air pressure.


Edited by TreyandSusan
Link to comment
Share on other sites

On Edit: Trey good add on thanks.

I don't recommend vinegar for the Sulphur Iron reducing bacteria that makes the foul smell. It is great for descaling which is a separate maintenance item from getting rid of the bacteria. This would explain why some folks say they have to keep sanitizing it. Vinegar will mask the odor but I have seen nothing in the research that says vinegar kills Sulphur/iron reducing bacteria. Again the water is safe just smells. 

If the cold water side smells too it is the fresh water tank that needs sanitizing. If both the water heater and the fresh water tanks need sanitizing.

Since I sanitized my freshwater systems only once a year, just AFTER leaving our two or three month stay at our then Louisiana winter quarters, or again if the rotten egg small comes back.

Using filters is necessary for me and a sediment before a second canister with an activated charcoal filter removed the chlorine and other bad taste elements to make any public tested water supply taste good regardless of the taste unfiltered.

For me, reversing the hoses and treating the filter canisters/outside/city water inlet/fresh water filer lines/inside plumbing lines including shower pipes all at once is an all day affair, mostly waiting as the bleach works. I fill a gallon bucket of fresh water before sanitizing from a potable supply where we are camped if no Sulphur bacteria in its water. If it happened there I just get a few gallons at a grocers.   

The gray tank stinks too and I empty it before sanitizing then close the Gray tank valve. Using the fresh water with bleach in it is fine for dishes and colorfast laundry. Remember we are using from a 1/2 cup or a bit more depending on your water tank capacity. When doing laundry we put that much in a small washer basket. I would not shower or drink it until flushed. But do use it so some goes into the gray tank.

After about 4-8 hours of everything soaking in the bleach solution I put the empty filter canisters and hoses back as used, flush the freshwater system by running the pump and draining turning on all hot and cold water spigots until the bleach small is gone. Then I open the low point valves at the bottom or bottom side of the fresh water tank until empty. Then a refill with fresh water the water heater tank into draining from the fresh water tank low point valves.


As a cleaner, white distilled vinegar is a great choice. It contains 5 percent acetic acid, a compound that can dissolve dirt, debris, and grime.

However, as a disinfectant, vinegar has limited uses. It can only kill or reduce certain types of pathogens, such as:

Source:  https://www.healthline.com/health/is-vinegar-a-disinfectant#disinfectant-properties 

Vinegar for descaling is great! Remember the Sulphur and iron reducing bacteria can withstand very hot water that most bacteria cannot. Bleach for me. Hydrogen peroxide? Never tried it.

More RV specific solutions:


Do not mix bleach, and alkaline, with vinegar, and acid. Gas and reactions can be very harmful.

"Sodium hypochlorite is made up of a sodium, oxygen, and chlorine atoms. When this molecule is mixed with the acetic acid in vinegar or other types of acid, it releases chlorine gas. Chlorine gas is extremely dangerous to human health. It’s so powerful that Germany used it during World War I as a chemical weapon."

Source: https://www.healthline.com/health/bleach-and-vinegar#what-happens-when-vinegar-is-mixed-with-bleach


Edited by RV_
Link to comment
Share on other sites

  • 3 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...