Water heater stink and color of residual water

[Rideblue51]

I have an Atwood GC6AA-10E water heater. It's been getting a sulphur smell in it so I sanitized it with bleach a couple of trips ago. Seemed to help a little but not really. Next trip, same thing and I thought maybe it was because I didn't drain the tank and the water was in there for a couple months. Draining the tank always made a mess coming out of the drain so I installed a short hose with a valve on the end. Tough to drain that way I guess because of the check valve in these new systems. Anyway, I drained the tank thinking that would take care of the issue. Today drove 3 hours to destination. Get out of the truck to set up and see white dried fluid all over the side of the rig emanating from the little drain valve at the end of the drain hose for the water heater. Was slightly open and I guess some residual water came out. White? Alkaline? Anyway, go in the rig to open up faucets to fill water heater, bad sulphur smell again. I can't win. Any suggestions? Had the old 10 gallon style before for 15 years and never had an issue. Changed the drain plug on that old one that has the thing on the end that slowly disintegrates. Do I need to use that style on these new ones? I was with the understanding that it wasn't necessary with these new ones.

[Second Chance]

Perhaps there's something useful on this page:

https://www.corroprotec.com/blog/sul...BoCqTIQAvD_BwE

Rob

[sande005]

Atwoods don't have an anode to replace. So the issue is bacteria growing.
The white residue is minerals that have precipitated out of the water - just like hard water stains on showers and coffee pots, except a lot more.
Your fitting is exacerbating the issue, as the flow of water when draining the heater is reduced, meaning less of the residue is getting flushed out.
Bleach solutions get neutralized very quickly, and it can be very likely that bacteria hide in the residue and never encounter the bleach. Hence why the problem returns.
Try repeated flushing of the heater without the fitting. Even better, Camco makes a hose wand that can go in the output to help spray out the heater tank.
Then resanitize with bleach solution.

I've never done it, but mild acids (vinegar) can help dissolve/loosen any build up. I'm sure there is an RV specific product someone would love to sell you to help.
Best would be to call Atwood, and get their advice first - to avoid anything that may potentially harm the heater.