Update and bump: I finally got around to replacing the anode rod today with a zinc aluminum rod purchased on line. I took this picture of the old and new anodes:
As you can see, the old anode is pretty much shot. When I flushed the tank out, all sorts of black junk came out. I think the iron reducing bacteria were eating the manganese chunks coming off of the rod. This water tank is only three years old, it kind of floors me that the anode rod would go so fast. A part of it is the water from the old well, which was acidic, ph around 5.5 or so. The new well water is neutral, ph is 7 so perhaps the new anode rod will last a little longer. I will have to add that the my annual check list of things to check.
Update: I investigated the hotwater heater anode today, I think I found the culprit:
I have ordered a new zinc/aluminum anode today and I will install it as soon as it arrives. In the mean time, I poured about 1/2 a cup of bleach in the open port where the anode was installed. That took care of the rotten egg smell temporarily. Getting a new anode should make the fix permanent. There is a lot of information on the web about water heaters and sacrificial anodes. The purpose of the anode is to prevent the steel tank walls from corroding. If the anode wears out, then the tank will eventually fail, leaving the home owner to replace the entire hot water tank. Most people recommend checking the anode every 3 to 5 years. The above anode is 3 years old.
This one has me scratching my head a bit. Our hot water is now smelly (like rotten eggs), not the cold water, just the hot water. This is a recent development which likely has something to do with the new well. Here is what I know:
- Our well has ferric iron (mineral iron dissolved in the water).
- We are using a green sand filter to remove the dissolved iron, it appears to be doing a good job (the water looks clear and does not turn brown when exposed to air).
- The green sand filter backwashes twice a week.
- The well and filter went on line about two month ago, the smelly hot water just showed up about a week ago
- It is only the hot water
- I have drained some water out of the bottom of the hot water tank, the first gallon or so came out dark, the rest came out clear.
- The water tank (electric) is about 3 years old
- The temperature is set to about 110-120 degrees
Obviously, it seems that some type of iron reducing bacteria is in the hot water tank creating hydrogen sulfide (H2S) which accounts for the rotten egg smell. But where is the iron coming from? Is the green sand filter not getting all the iron?