If it really is the hot water tank creating the sulphur smell you can rinse it with a vinegar/water solution.
Rotten egg smell in the hot water.
One of the fun things about RV repair is it is very common to find varying
opinions about solutions and caused for the same basic problem. I have found
three different techniques to this problem. The cause always seems to be pretty
much same however.
Cause: Sufficient amounts of sulfur in the water to produce an odor. This is
caused by the electro-galvanic action of either the special 15% thickness of the
type 7072 aluminum (pure aluminum and zinc) that is fused to the inside of
Atwood tanks since 1988 or the anode rod in the Suburban. Bacteria in either
brand can also cause it.
: Turnoff the water heater and let water cool if need
: Drain and flush the tank. By flush I mean let fresh
water run through the tank quite awhile and get out all the sediment that can
settle in the bottom of the tank. The agitation action of the water coming into
the tank should help unsettle and flush the sediment. Compressed air can also
agitate the sediment or you can use a bent stiff wire or brush and go in through
the drain hole to stir things up. If you do this be not to damage the threads.
This is also a "tool" available in most RV stores that hooks on the end of a
water hose and is specifically designed for this purpose. The primary objective
here is to get the sediment out. I might also advise to be certain the water you
use to flush does not have a sulfur odor. Keep the drain hole clear as the
sediment can stop it up.
: (optional): Remember the varying opinions? Here is
one. Fill the tank with 2 parts distilled vinegar to 1 part water and let set at
least 2 hours. That is a lot of vinegar! I checked to be certain my manual did
not have a misprint and that is the correct ratio. Let it sit for a couple of
hours and rinse with fresh water. To fill the hot water tank only you must go
through the T&P valve (the valve on the top of the outside of the tank with
a lever and metal tag on it.) Screw a male fitting into it and let gravity feed
the solution in through a funnel and flexible hose (open a hot water faucet to
let air escape). You can also go through the drain valve or anode rod opening
using the same procedure. Your can open the T&P valve to let air escape. Be
sure to hold funnel/hose high. The third way is to pump it through the fresh
water system. This will also pump the vinegar water into most of the rest of the
system. You will need to flush real good before proceeding to the next step.
: (optional): Add about 4 teaspoons of household
detergent for every 10 gallons of water into the fresh water tank. If you will
add a little detergent then water then detergent then water, and so on this will
help mix the solution. Run this solution through your whole water system (all
faucets, valves, and toilet). Use your water pump and continue putting in water
and pump through until the detergent is gone. Be certain to remove faucet
aerators and shower heads during this procedure. Reinstall them before the next
: (recommended option): Do the same as step 3 using
common household bleach at 5-6 ounces (2/3 to 3/4 cup) per 10 gallons of water.
You might let this set in the system for a couple ours to a few days. Then flush
out till chlorine smell is gone. Some people advise this step may need to be
repeated several times.
As you can easily see, Step 4 & 5 also help freshen your
: When you are convinced you have all the vinegar,
detergent, and bleach out, close the system and refill the water heater and the