Shower water smells like septic

2015 Bighorn 3875FB.
No problems with water for first 2 years. In 3rd year when using the shower, the hot water smelled like sewer water for a few minutes but would clear up and smell would dissipate. Doesn’t matter if we’re in Virginia or Florida, same smell. Tried draining the hot water tank and fill it with vinegar, heat it and run it til cold. Worked for about 2 weeks. Tried small amounts of Clorox which worked for a while then the smell came back. Now (3yrs more) problem still exists but now cold water smells just as bad. Have to run hot and cold water for 2-3 minutes and run fantastic fan on high to remove the smell. All other water has no smell hot or cold. Sounds stupid but is a real problem.
Anyone else have a similar problem?

It's seems more likely you're getting gray tank odors while using the shower. This could be a venting problem. Start by checking under the sink for a Studor Air Admittance Valve. It's supposed to act as a vent, allowing air to flow into the drain. If it's stuck open, odor from the tank will come into the room. If you have one, put a plastic baggie over it with tape or rubber band as a temporary bypass to see if the odor goes away. If yes, you can get a replacement at many hardware stores.

Another place to check is on the roof. The shower could vent there.

If you don't think it's coming from the drain, but rather from the water out of the shower, you might fill a bucket with that water and take it out of the bathroom to evaluate the odor. If it does smell, then you may want to use the antifreeze intake to pump a diluted chlorine solution through the water lines. Since you've already treated the water heater, maybe bypass it this time. Run the solution through each faucet and fixture and then let it sit in the lines for 3 hours before rinsing. Don't forget the outside shower and washer prep.

Outakash said:

2015 Bighorn 3875FB.
No problems with water for first 2 years. In 3rd year when using the shower, the hot water smelled like sewer water for a few minutes but would clear up and smell would dissipate. Doesn’t matter if we’re in Virginia or Florida, same smell. Tried draining the hot water tank and fill it with vinegar, heat it and run it til cold. Worked for about 2 weeks. Tried small amounts of Clorox which worked for a while then the smell came back. Now (3yrs more) problem still exists but now cold water smells just as bad. Have to run hot and cold water for 2-3 minutes and run fantastic fan on high to remove the smell. All other water has no smell hot or cold. Sounds stupid but is a real problem.
Anyone else have a similar problem?

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Since the smell is only in the shower and you seem to have done almost everything else, I believe the smell is coming from your p trap in the shower. When you run enough water thru it, the smell goes away. First thing I would do is plug off the drain and see if the smell continues. My guess is that there will be no smell. I would put a cup off baking soda down the drain followed by a cup of vinegar. Let sit for a couple hours and then pour a gallon of hot water slowly down the drain. Hopefully you’ll wash out the bacteria buildup.
If this doesn’t help, you have a bath venting problem or one extra thought that if it’s not the drain, you have some kind of a chemical reaction going on in the shower faucet.

If the studor valve test that Dane spoke about didn't provide positive results try bleach.
Drain your fresh water tank then pour some bleach in you fresh water hose then fill the onboard tank. Open each spigot until you smell the bleach. Let stand for 15 minutes then drain an rinse.
If there is a filter in line remove it and put a new one in.

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This has happened to me. The problem is the anode rod in the water heater. Anode rods can be either aluminum or magnesium. Under certain conditions, there is a reaction that creates sulfur compounds. This stuff is harmless but you get the sewer gas smell. Flush the water heater and change the anode rod and this will go away. An aluminum-zinc anode rod is supposed to prevent this.

Gary521 said:

This has happened to me. The problem is the anode rod in the water heater. Anode rods can be either aluminum or magnesium. Under certain conditions, there is a reaction that creates sulfur compounds. This stuff is harmless but you get the sewer gas smell. Flush the water heater and change the anode rod and this will go away. An aluminum-zinc anode rod is supposed to prevent this.

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If you pull out the anode rod and it's covered with a white slime, you've got bacteria (from the water source). The bacteria produces hydrogen sulfide, which is the rotten smell. Recommend you set up a two stage water filtration system for your rig with the second stage a filter for cysts and other nasties. Check RV Water Filter Source for filter suggestions.

Gary521 said:

This has happened to me. The problem is the anode rod in the water heater. Anode rods can be either aluminum or magnesium. Under certain conditions, there is a reaction that creates sulfur compounds. This stuff is harmless but you get the sewer gas smell. Flush the water heater and change the anode rod and this will go away. An aluminum-zinc anode rod is supposed to prevent this.

Click to expand...

Agree with comments on anode rod,I was experiencing same issue, stunk like crazy for a few seconds and then disappeared,the anode was deteriorating badly. I flushed tank and replaced anode...no more smell

Resurrecting this post. Getting a skunky smell for the first couple of seconds when turning on the shower. Took off shower hose and head and put in a baking soda/vinegar solution for a couple of hours. The hose still smelled after doing this so think the plastic hose needs to be replaced since it evidently has been infiltrated by something causing the smell. Shower head appears to be OK. Secondly, getting a musty smell from the shower drain. Went behind the storage wall and removed the shower p-trap and cleaned. Also cleaned up the stand pipe to the drain. After doing this, the smell is still there. Since the p-trap is full of water, the smell must be coming from the pipe going from the drain to the p-trap. Both Air Admittance Valves have been replaced by Studor valves in the bathroom sink and kitchen sink. Have used a baking soda/vinegar mix in the past down the shower drain - will try again tomorrow. Running out of ideas on how to fix this smell issue. And yes, I have replaced the anode rod also.

You could try cleansing your water system.
What I do is empty the fresh water tank. Then I pour a 1/4 cup of chlorine in my water hose add fresh water to the tank. I don't fill it, just enough to run bleach water in and through all my water faucets. When I smell bleach at all the faucets I wait 15 minutes then flush the lines with clear water no bleach. Empty water tank and refill.

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