Hot Water Odors

When odors are found in your hot water only, the most common cause is that the water heater is fitted with a magnesium (anode) rod, which is used to protect the tank from corrosion. But the magnesium also is a food source for non-pathogenic, sulfate-reducing bacteria. Those bacteria can create a very strong sulfur odor. Ironically, the odor was less common years ago when water heaters were set to 140 degrees instead of today’s 120.

How to Get Rid of the Odor

Unfortunately, removing the magnesium rod negates the manufacturer’s warranty. Changing the rod to aluminum doesn’t seem to help. Once the water smells, raising the temperature to 140 degrees doesn’t help. And chlorinating the well is a short-lived fix.

So, there are two ways to solve the problem:

  1. Remove the magnesium rod and chlorinate the hot water tank with a pint of liquid bleach (Clorox). Allow it to sit for several hours (3-5), then run the water until it’s clear and odor-free. Note: some of the magnesium rod may have disintegrated and fallen to the bottom of the tank. If so, it may provide a little food for the bacteria. But will be used up within a few weeks.
  2. Chlorinate the water heater by using a simple cartridge filter as the “dosing” station. To do so, simply unscrew the filter sump, pour out the water (leaving the old, wet filter inside), add a pint of chlorine (Clorox), open a hot-water faucet, and let it run for two minutes. The chlorine will go directly into the water heater. Allow it to sit for several hours (3-5), then run it till it’s odor-free. You may need to repeat that process periodically.

As always, please call us if you have any questions.