You will have a shut off for the commode and each sink. The only way to turn the supply to the shower is to turn off the supply to the entire home.
advise the customer to store some water as the supply is going to be turned off.
You go to the bathroom and run on the hot water faucet.
It could be mould. If you don't turn on (or you don't have) a fan in the bathroom to remove steam, condensation can be left on the walls and black mould can grow where it is wet.
It is absorbed into the drier air from outside the bathroom.
Replace the faucet.
first turn water off at main supply. remove handle and loosen packing nut around handle shaft use good pliers to turn shaft clockwise.it may be hard but they should break loose.once working retighten packing nut till water stops dripping from shaft.
City water can have additives in it such as fluoride. This can make the water have an odor to it.
Check the shut-off valve for the hot water side that's under the sink and make sure it's fully open.BECAUSEThe installer did NOT remove the aerator prior to the installation and the flow restrictor is blocked
If there is a downstairs bedroom, expand it to include an efficiency kitchen, a bathroom suite and a large walk-in closet. If possible, a private entrance would also be an advantage.
Just keep a cup (plastic, or a spare coffee cup) on the bathroom sink, fill it with your water, then shut off the water.
You need to turn it off at the base of the sink. Or depending on the problem you may need to turn it off at the water main valve.
Probably the hot water heater is off, either it has broken down or the pilot light has goen out.