YES and No Yes if you are going to be working on the gas water heater and No if you are working on a cold water line and if you are working on a hot water line you can shut off the gas or electric to the water heater so in case your water heater drains but what I usually do is just turn the water heater's water supply valve off.
because the water is turn off
Have the new valve in hand. Cut the toilet water supply off at the commode, or even at the street meter box.Remove water tube or pipe supply and old flush valve. Install new valve and new supply line if required.
air in the water lines causes banging and whistles/screams. Turn off main water, turn on the faucet, turn main water back on, and it should force the air out.
Turn off at curb stop to decommission whole house or building. Inside of house or building, turn off valve at main water supply at meter and cut and cap cold water line to be decommissioned.
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.
I think your fill valve is clogged with seddiment.Just replace it.
This is becasuse of shape of commode. The lower part has a upward bend which does not allow the commode to go empty. Only water which has a prresure can go over the bend and moment the presurre is stopped, the last portion of water can not climb the full bend and therfore remain at the bottm of commode.
take the bolts off there should be two bolts on the bottom under plastic caps Turn water off at toilet, flush toilet to empty tank. Two nuts under decorative caps at the pedestal where it meets the floor.. lift toilet off after loosening. There is a wax ring seal that may offer a little lifting resistance.
The float valve shutting off the water flow.
Commode / Water closet
To turn off the water to the water heater, locate the shut-off valve on the cold water pipe leading into the water heater. Turn the valve clockwise to shut off the water supply.
To turn off the water supply to the water heater, locate the shut-off valve on the cold water pipe leading to the heater. Turn the valve clockwise to shut off the water flow.
To turn off the water to the hot water heater, locate the shut-off valve on the cold water supply line leading to the heater. Turn the valve clockwise to shut off the water flow.
To turn off your water heater, locate the shut-off valve on the cold water supply line leading to the heater. Turn the valve clockwise to shut off the water flow to the heater.
To turn off your water heater, locate the shut-off valve on the cold water supply line leading to the heater. Turn the valve clockwise to shut off the water supply to the heater.
To turn off the toilet water, locate the shut-off valve behind or near the toilet. Turn the valve clockwise to stop the water flow.