I want to replace the faucet for my kitchen sink. The shutoff valves for both hot and cold are stuck open.
I assume I should either try to unfreeze the valves or eventually replace them.
If I'm in a hurry to replace the faucet (it's leaking onto the countertop), is there any reason not to just turn off the house water supply while replacing the faucet?
In general, there's no problem using the main valve. However, if the sink valves are stuck, you might find that the main is also in poor repair. If the main is old and rarely used, you might find that's it's stuck or will become stuck once closed.
If the main valve is a gate/globe valve, and it looks old and cruddy. You might want to consider replacing that valve as well. I'd recommend replacing it with a ball valve.
Generally shutting off the main causes no serious problems. Open the lowest faucet (usually an outside spigot or basement sink) to drain the pipes. As a precaution I remove the faucet aerators prior to turning the water back on. The rush of water back into the pipes can dislodge sediment and clog the filter in the aerator.
No. My hot water valve is stuck open as well, so I just turn off the master valve on the main line.
If your home has a 50-gallon header-tank in the roofspace (common in older homes in some parts of the world) it would be advisable to either turn off the outlet valves from the tank or to use rubber bungs inside the tank.
Otherwise you have to wait for 50 gallons of water to drain out, which is both tedious and wasteful.
If you use the main valve and your house has a level above where you are working, you will have to wait for the water to drain out from any higher plumbing. If you disconnect the line under the sink, all the water will want to drain out of there. Use a lower faucet like an outside one if possible, but that will only drain cold water.
