Water smell

Can’t quite figure this one out.

I have a friend who owns a home that is approximately 7 years old. He has an odor he describes as slightly “sulfurous” that comes from ONE sink in his house. In particular it only comes when the hot water is running in that sink, and only for a short while (30 seconds or so). The smell does not remain once the water is shut off, and after running for 30 seconds, he can not smell it any more. I did an informal look at this house about a year ago when he bought it - there were no cross contaminations or signs of trouble (or diy plumbing)

Any idea what would cause a smell like that from only ONE faucet? Bathroom faucet, used several times throughout the day. The friend is also a clean-freak, so nothing obvious about dirty sinks :stuck_out_tongue: .

Any ideas from you plumbing guru’s?

Is this a well system?


If the Odour is present only on the Cold, it may be H2S (Hydrogen Sulfide) that is present in the Well water.

If the Odour is only present on the Hot, it is caused by a defective anode rod at the Water Heater.

Jeff -

Yes, he has a well system. My first thought was H2S from the hot water heater, but I’ve never heard of the smell coming from only one faucet in a house. He has tested (for smell) on various faucets (after allowing for his sense of smell to return) and has never detected the odor anywhere else.

I’ve heard of the bacteria growing on the hot water heater anode causing H2S, but my understanding is the smell would eminate from any hot water source - is it possible for the bacteria to randomly grow inside the hot water lines for one faucet only? (Not a science guy, but I dont believe it is…?)

Thanks for the reply.


Directed him to the websites listed, among a few others I found. Couldn’t find anything in any searches mentioning the smell coming from only one supply, but H2S is the most likely source still.

Thanks all for the links.


I’m on a well system too and the only time I got that smell was when the water heater anode was just about shot. But it came from all faucets.

The easiest way to clean out the whole system is the old reliable bleach treatment. I use it twice a year. Add 1 gallon bleach to well pipe and run the closest hose down the well pipe until you smell bleach coming out of the hose. My well is 8’ pipe at 215’ deep and it takes about 15 minutes to smell the bleach. Once that is done, open all the faucets in the house until you smell the bleach. When that is done, let it sit for 24 hours.

After it sits, run the outside faucet out to the yard and let it run until you don’t smell the bleach. Then run the inside faucets until they are clear also. The water will be great tasting and it takes care of any potential coliform also. If you are on septic, put 2 packets of dry yeast down the toilet to help counter the bleach.

As a warning, the bleach will clean out the lines and the pump but you will find that it will pick up sand and any rust in the lines that might clog the screens on the faucets. I always take the screens off before I clean out the lines.

This was taught to me by the head of my local county’s water treatment department. They use other chemicals for the county wells but he always used the bleach for his personal residence and said it works as well.

Done that…works well. Had to do it 6 months later again…been 2 years. Works well. :smiley:

Borrowed from the county health dept.