I'm having this same issue. We have well water. The problem appears to only be one faucet, and cold water only. I think the problem started when one day I ran 2000 gallons through my water softener without re-charging (usually re-charge at 400 gallons). I'm new to well water and made the mistake. Most water in my house does not have the smell, but this one bathroom faucet does. And it only seems to have the problem if it is left off for a while. The smell is pretty strong, too. Enough that it is not drinkable.

If this is enough information, I'd appreciate any advice.

-Chad

Not enough info. Is this fuacet on soft water, or hard.

It is softened water. The faucet is in an upstairs bathroom that has two faucets and a shower. The pipes for both faucets are not visibly joined, but probably join somewhere in the wall. One faucet has the issue. The other faucet and shower head in the bathroom do not produce smelly water.

FYI, my post was originally made as a reply on another thread. I did not write the subject to this thread, and I believe some information was lost due to the context of my response. Sorry about that.

The smell is a very potent sulphur / rotten egg smell. If you leave the water running a little while, the smell is reduced a lot. But will come back after an hour of in activitiy.

Also, the faucet is used daily. It is the faucet my wife would usually use to wash her face, etc.

Thank you in advance for any help / information that can be provided.

-Chad

Chad, I didn't change anything that you posted.
You piggybacked your complaint onto another post and that's confusing.
Perhaps you figured if we answered him that your problem would be solved.
That's not how it works here. We give each poster individual attention because even though the problem might sound the same the solution might be entirely different.

Now, on to your problem. Sounds like some smelly bacteria moved in. Uscrew the aerator , (see image) and see if the water smells better. Still stinky? The water off and open up the faucet. Pull the cartridge and soak it and the aerator in bleach. Now block off the spout and pour bleach in the open valve and let it set for a hour. Reassermble and flush by running water.
Let me know if it comes back. Good luck, Tom

Thank you for you response, Tom. I agree you didn't change what I wrote, but the detail of a sulphur smell was lost when my response was moved off the original thread, and I feared this new subject was not very descriptive. In the future, I will start my own thread from the beginning. Sorry if I made things confusing.

Back to my issue, I have removed the aerator and flushed water through the faucet for a long period. However, the smell returns if the faucet is left idle for a while.

I will now try your suggestion about soaking the cartridge and the aerator in bleach.

Could you clarify what you mean by blocking off the spout and pouring bleach in the open valve. Do you mean to shut off the water supply under the sink, disassemble the faucet and separate the water line of the faucet away from the valve. Then pour water down the hole in the faucet spout and have it come out the disconnected line under the sink? Does my question make sense?

Thank you for your help, Tom.

-Chad

Could you clarify what you mean by blocking off the spout and pouring bleach in the open valve. Do you mean to shut off the water supply under the sink, disassemble the faucet and separate the water line of the faucet away from the valve. Then pour water down the hole in the faucet spout and have it come out the disconnected line under the sink? Does my question make sense?
My fault for not explaining it more clearly. If you followed directions you will have shut the water off at the angle stops in the cabinet and opened the valve, ( I could be more helpful if you would give me the brand name of your faucet.) and remove the cartridge. If you poured bleach in the opening left by the cartridge it would simply pour out the spout. Block off the spout to keep the bleach in the faucet. All clear now? Good luck and I hope it works. Tom

( I could be more helpful if you would give me the brand name of your faucet.)

I'm not possitive of the model number but the faucet looks very similar to the Delta faucet 3530-24. Intead of a cartridge, it looks like I have a stem unit. So I plan to remove the stem unit from the cold water handle, I'll add some bleach and let it sit. Also, I think I'll do the same with the hot water handle. I want to bleach the heck out of things.

If you have any other hints, please share.

Thank you for your help. I'll report back on my results.

-Chad

Try that and get back to me with the results. If that don't solve the problem we'll go to "plan B". Regards, Tom

Success! Thank you so much, Tom!

I made the mistake of using a full strength bleach, instead of watering it down. If I had to do it again, I would probably use five parts water to one part bleach, from reading other articles on the internet.

After opening up both handles and removing the stem units, I used a can of compressed air to blow out the water from the lines. Then I poured bleach into both stem holes until a little came out of the spout. And I placed the stem units and aerator in bleach. Everything sat for twenty minutes. Only twenty minutes because I was worried I shouldn't have used pure bleach. Then, I re-assembled and let the water run for an hour on full blast. After the water was off for an hour, I smelled a slight bleach smell when I poured a cup so I turned the water on for another hour at half blast.

This morning, there was no smell at all. A beautiful thing.

Thanks again,

-Chad

You're most welcome Chad, Just glad we coul help. Glad you got it stopped before it spread. Have a good one, Tom