Water smells like sulfur

[Randog83]

What causes water to smell like sulfur and how do you get rid of it?

[Javi]

Most likely you need to drain and flush your water heater.

[NH_Bulldog]

The water heater could be related, but can you share some other details? Like are you running off the onboard fresh water tank or city water? What is the source of the fresh water (municipal water supply, campground water supply, home water supply, well water, etc.). Have you flushed and sanitized your RV water system before use? How long has this been an issue?

Very often the heating of water can cause minerals to precipitate out of solution and if your water heater has an anode rod (some do, some don’t), it can react with those minerals and cause bad odor and/or taste, but only on the hot water side. If your concern applies to both hot and cold water ( after a good system flush), then the issue is somewhere else.

[flybouy]

Has the camper been setting in the heat with the water heater filled? Very common issue in the summer time. Remove WH anode a flush well with fresh water. You can buy a WH flush tool that attaches to a garden hose and the angled outlet can be inserted and rotated to flush out the tank.

Drain the fresh water tank. Fill with water and about a1/4 cup of bleach and run the FW pump by opening all the faucets (incuding outside shower or kitchen) and flushing the toilet until you smell bleach at every outlet. Let it set for an hour to overnight then drain FW tank and fill with fresh water only and repeat until there's no bleach odor in the water.

[JRTJH]

Just a bit of "clarification"...

There are several types of RV water heaters and they all are built with different style tanks (or no tank at all in some modern "tankless water heaters)...

Two brands typically used in Cougar trailers are Atwood and Suburban.

This is from the Atwood Owner's Manual:

"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 main water supply. Drain the water heater tank and
reinstall drain plug. Remove the pressure-temperature relief valve.
Mix solution of 4 parts white vinegar to two parts water. (For a 10
gallon tank, use 6 gallons vinegar to 3 gallons water). With a
funnel, carefully pour solution into tank.
2. Cycle water heater with the above solution, letting it run under
normal operation 4-5 times.
3. Remove the drain plug and thoroughly drain all water from the
tank. 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 valve on the rear of the
tank or through the pressure-temperature relief valve coupling
located on the front of the unit.
TO FLUSH TANK WITH AIR PRESSURE:
Insert your air pressure through the pressure-temperature relief valve
coupling. With the drain valve open, the air pressure will force the
remaining water out of the unit.
TO FLUSH TANK WITH WATER PRESSURE:
Fresh water should be pumped into the tank with either the onboard
pump or external water pressure. Continue this flushing process for
approximately five minutes, allowing the fresh water to agitate the
stagnant water on the bottom of the tank and forcing the deposits
through the drain opening.
4. Replace drain plug and pressure-temperature relief valve.
5. Refill tank with fresh water that contains no sulphur.
The Atwood water heater is designed for use in a recreation vehicle. If
you use your vehicle frequently or for long periods of time, flushing the
water heater several times a year will prolong the life of the storage
tank."

This is from the Suburban Owner's Manual:

"ODOR FROM HOT WATER SYSTEM
Odor from the hot water system is not a service problem and many water
supplies contain sufficient am ounts of sulphur to produce an odor. The odor is similar to rotten eggs and is often referred to as "sulphur water". It is not
harmful - only unpleasant to smell. Sulphur water can be caused by a
chemical action or by bacteria. The solution to eliminate is chlorination of the water system . Add about six (6) ounces of chlorinated common household liquid bleach to each 10 gallons in the water tank. Then run the chlorinated water throughout the system, opening each faucet one at a time until you
smell the chlorine. Let the RV sit for a few days and the chlorine should take care of the problem . Then you will need to take care of the chlorine.
Remove the chlorine by flushing the system with fresh water. This may take several attempts. You may consider adding a filtering system that removes chlorine and prevents sulphur water. If the sulphur or rotten egg smell continues, flush the system once again as described above and replace anode rod as necessary."

[dutchmensport]

The most common cause of the Sulphur (rotten egg) smell from hot water in the camper is because of the magnesium anode rod in the water heater.

Pull the drain in the water heater, remove the anode rod, flush the tank out. (You can find YouTube videos how to do this... very easy), then replace the magnesium anode rod with an aluminum one.

Magnesium rods (the sacrificial rod) inside your camper is designed to deteriorate. This protects your water tank. It deteriorates before the tank does. There's a chemical reaction occurring, always, inside these tanks, that's why you must have the rod. The problem is, the magnesium rods deteriorate quickly and the disolved particles sit on the bottom of the tank. That is where the odor is coming from.

The solution is very simple... just flush out the water heater. Drain it, flush it, and put the rod back in.