You want to get an aluminum/zinc/tin anode rod if possible. This is said to reduce the rotten egg smell you are talking about....Anode rods are available at some home supply stores and all plumbing supply houses...checkout these sites for more information on these rods and the issues associated with them
Water Heater Anode Rods
Water Heater Help: Fixes, tips and caveats
According to what I have read, you may also need to do a
hydrogen peroxide cleanse of your water heater (see websites provided).
OK..anode rod is either by itself under a 1-1/16" nut (or 1-1/18" nut) or it is integrally built into the hot water nipple at the hot water tapping. If you see a large nut on top of the heater ..that is the anode rod. IF THE NUT TYPE, all by itself, then you need to shut off water, drain say 5 gallons off the heater and then remove the anode rod using a 1/1-16" six-sided socket and ratchet tool..you will also need persuader as these nuts are factory set and are tight (makes a SNAP sound when you finally release)..then back out, observe...does it look deteriorated? If so..off to the supply house....research which type is best for you ( I think the aluminum/zinc/tin rod fits your profile).
If rod is integral to the hot water nipple, then shut water into heater off and drain 5 gallons off at heater and then cut hot water pipe and remove the hot water nipple...observe the rod..look beaten..? Then off to supply house.
AT this time you may also want to add a bottle of hydrogen peroxide (either in anode rod tapping or hot water tapping of heater) and follow directions provided at the website I provided (basically, will not hurt you guys...just run your water out for 30 seconds so the hot pipes at end run also get treated.....
this hydrogen peroxide kills bacteria that make these smells.
If anode rod looks good...definitely bacterial here...if not, may be just the rod and water hardness causing odors.....read up at these sites and let me know your thoughts.
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