When you smell sulphur coming from your house's pipes, whether the taps or the drain pipes, several potential problems could be causing the smell. You should not ignore the sulphur smell since it may indicate the presence of toxic gasses in your house or bacteria growing in the plumbing system.
Sewer gasses contain a number of gasses, including sulphur. If you smell sulphur in your house's plumbing, specifically coming from the drains, the smell may indicate the presence of sewer gasses in your house. Sewer gasses will cause health problems for anyone who breathes them in too long and can explode if exposed to open flame. The p-traps or the curved pieces in the house's drain pipes act as natural blockers against the entrance of sewer gasses, unless the pipe connections have leaks or nobody has run water down a drain in so long that the water in the p-trap has evaporated.
The drain pipes in the house all connect to vent pipes, which serve to vent sewer gasses in the drain pipes safely outside the home. If you look at your house's roof, you will see the vent pipes poking up. Sometimes tree leaves, twigs or debris dropped by animals falls into the vent pipes and clogs them, allowing the sewer gasses to come into your house. Damage to the pipes inside the house's walls will also allow sewer gasses to leak into the house.
If you smell sulphur in the water coming out of your faucets, the problem may have to do with sulphur gas in the water supply or bacteria growing in your plumbing. Decaying organic matter from plants or animals may make its way into the water supply and will produce sulphur gas. The presence of minerals in the ground, which contain sulphur, will also introduce sulphur to the water supply. Bacteria growing in your water well, water filter system or the water heater will also produce a sulphur smell in the water.
Clearing obstructions from your house's vent pipes may eliminate the sulphur smell. If the smell comes from the water, run the hot water and then the cold water to determine if both smell like sulphur. If both do smell like sulphur, flush and clean the water purification system or clean your well. If just the hot water smells like sulphur, clean your water heater with a bleach solution. If you are unsure how to clean your house's plumbing or cannot clear obstructions from the vent pipes, contact a plumber for professional help.