Time for either the anode to be replaced or a good flushing. Some corroding anodes react with certain well water to get that awful smell.
Atwood (or Atwood Bowen for the real old timers)
And Suburban (formerly Mor-Flo and American Standard).
Many of the questions are specific to one brand only. There are some differences between the two. I will try in this article to address any differences that would be of consequence to the average RV'er in normal use and operation. It is not my intent to get into specific detailed technical troubleshooting and repair, but to address some common complaints and questions that the average RV'er can easily address.
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 causes for the same basic problem. I have found three different techniques to this problem. The cause always seems to be pretty much the 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.
Step 1 : Turnoff the water heater and let water cool if need be.
Step 2 : 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 careful 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.
Step 3 : (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. You 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.
Step 4 : (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. Clean and reinstall them before the next step.
Step 5 : (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 whole system.
Step 6 : When you are convinced you have all the vinegar, detergent, and bleach out, close the system and refill the water heater and the system.
