DHW and sulpher smell

[muncybob]

With the VERY warm temps here lately I decided to shut down the boiler and turn on the electric water heater. Boiler/water heater are piped such that I rely on the boiler coil for hot water in heating season and close the ball valve on the electric heater hot water supply line to the house. Today I closed the ball valve on the boiler hot water supply line and opened up the electric heater ball valve. Very strong rotten egg smell in the water at the faucet. Why?
I connected a hose to the electric heater drain and drained out a lot of water(for about 5 min.) but still have the smell. Do I need to drain more? Is there something else I should be doing? Should I have left the electric heater feed line open all winter?

 

[webie]

Its probably due to the stagnant water in your heater all winter . See if you can completely drain the water heater that should take care of it and as you use water it should get better , obviously you know its sulpher comeing from the water . I actually heat directly from a coil in my storage but I have my water piped so that it actually is cycling thru my water heater to avoid a stagnant situation . Next year you may want to just drain the water heater once you start burning wood.

 

[WoodEnergy]

I have the same problem. My well water (no chlorine) has a SMALL amount of sulphur (nearly undetectable) but also has iron bacteria/sulphur bacteria. This is a very basic lifeform that "eats" elemental sulphur, and emits hydrogen sulphide (as a waste), which smells like rotten eggs and leaves a black residue. This bacteria thrives in warm water (hot water tank). My somewhat flawed, temporary solution is to crank up the temperature to "max" for a few days which kills off the bacteria. Unfortunately, it returns within a few weeks, and I have to kill it again.
A better solution would be a chemical feed pump injecting chlorine to kill the bacteria, oxidize the iron and sulphur, and then a TERMINOX filter to remove the chlorine and rust, then a softener to remove the minerals. However, that takes money, which is in short supply right now :long: . See www.budgetwater.com
Hope that helps.
Steve

 

[muncybob]

If it's stagnant water in the heater will I run into the same thing with no circulation thru my coil in the boiler over the summer?

 

[webie]

Could be but your coil will be easy to flush out because there is not much water there .

 

[tbsdolmar]

The smell is caused by your anode rod in the heater. The factory rod is probably aluminum. You can change it to a magnesium or let it out and take the chance it will rust out quicker. This should take care of it.

 

[benjamin]

I thought it was the other way around, the standard anode is magnesium which can cause the hydrogen sulfide, and I cured it with an aluminum anode rod. I think I remember there was something about aluminum anodes functioning only under a certain temperature, and actually contributing to corrosion at higher temps. I turned down the temp to avoid this and also "flush" out the tank by using more hot water.

 

[tbsdolmar]

Sorry I had it backwards. It's magnesium from factory. You can get replacements in aluminum or a mix of aluminum/tin.

 

[muncybob]

Yep, the anode is magnesium. Flushing out and setting the initial temp to the max (165) seems to have cured the problem. I have since lowered the temp. Perhaps next winter I'll run the hot water thru the electric heater to avoid this in the spring or I'll swap out the anode since we normally keep the temp under 130.