With a few household tool.
Replace water shutoff valve under sink.
There are two basic types straight stops and angle stops and these valves normally remain on and are seldom closed functioning maintenance free for years.
If this happens to you you can simply replace the valve with a new valve that matches the old one.
Replacing a shut off valve compression valve or angle stop may seem like a daunting task but it really takes less than 5 minutes.
Cut the supply line with a pipe cutter leaving enough room between the escutcheon plate and the cut to allow installation of the valve fitting.
Open the faucet to drain the line.
Turn off the next valve up the line which may be the main water supply valve.
Shut off the water at the main shutoff valve.
Fortunately a bad shut off valve is extremely easy to replace.
These inexpensive little valves rarely get used and when they do sometimes they leak.
Turn on the water supply to the sink once the valve is back in place and the plumbing has been completely re secured.
Shut off the circuit breakers to an electric water heater.
The water to a kitchen or bathroom sink is supplied through small copper or flexible neoprene tubes from a small control valve called a stop or shut off valve under the sink.
The main water shut off valve stops the flow to the entire home from the water meter while other water valve types shut off the water at individual appliances fixtures and faucets.
Residential plumbing systems can contain several different types of water shut off valves that control water flow.
Prepare for valve replacement.
Then open a faucet on the lowest level of your house and another faucet on an upper level to drain the pipes.
As the line fills watch out for leaks.
Deburr the pipe with a deburring tool.
Place a bucket under the old valve.
When cutting the supply line cut slowly and gently so.