Rotten egg smell from kitchen hot tap

loveisdivine

Can anyone suggest might what be wrong here? Rotten egg smell coming from just the kitchen hot tap. All other hot taps/shower are fine and cold is fine too.

Noticed it first Saturday morning. Not sure if it's connected but Saturday afternoon, after heavy water usage, the washing machine gave an error that it wasn't getting a water supply. Waited for the tank to fill and once switched on again it was fine.

Hot water heater working fine, hasn't been off or ran at a low temp or anything.

Edit to add more info - We're on a private well, but we have a water softening system and reverse osmosis for the drinking water. We have a mixer tap in the kitchen and both the tap and sink are less than 6 months old.

monseiur

The rotten egg smell is hydrogen sulphite gas, the gas may be created by reaction between certain bacteria in the water with sulphur, aluminium anodes etc. in water heater or in pipe supplying your sink.
Mains water has chlorine added which kills the bacteria, hence the problem is more often associated with private wells etc.

One solution is to turn off cold water supply to water heater, open all hot water taps (assuming the problem is with hot water only) and drain water heater if not drained fully by opening taps.
Close all taps.
Add 4 to 5 pints of hydrogen peroxide to water heater and fill with water, open hot water taps one at a time until water flows, then close - this is to ensure the peroxide solution gets into all pipes.
Leave for 3 to 4 hours, then flush out the whole system fully.
If symptoms return in 2 to 3 weeks repeat the process above.

loveisdivine

Thank you!

To be honest I wouldn't know how to add anything to the water heater and I wouldn't be comfortable messing around with it. It's a pressurised unvented system and I'd be worried about getting air into the system or something!

If the source was the water heater would we not get the smell from all hot water outlets? Or are you saying it could be confined to 1 particular pipe?

monseiur

The culprit may be along the pipe supplying the sink, at a joint, bend etc. where a combination of metals meet to create the right environment for the gas to be created. It may very well be at the point where the copper pipe is connected to the tap - but the system has to be treated at least once to remove the cause, hence it's important to ensure that the peroxide mix gets into all the pipes & taps.
It's a job for a handyman/plumber. By the way I'm not an expert, but there are some professional plumbers on here who may be along later with more thorough & expert advise.
Although the smell can be off putting it's not a health hazard in this instance.

M.