Shutoff valves: five minutes that can save a flood

The main shutoff

Go and find it now, in daylight. In most South Bay houses it is one of three places:

• Outside, on the wall facing the street, often near a hose bib.
• In a concrete box at the edge of the property, with the water meter — the lid lifts with a screwdriver.
• In the garage, where the supply enters the building.

When you find it, do two things. Turn it off and back on again, so you know it moves and so it does not seize in place. And tell whoever else lives in the house where it is. A shutoff that only one person can find is half a shutoff.

If it will not turn, or it turns and the water keeps running, that is a plumber's job and it is worth paying for before you need it rather than during.

The valves under each sink

Under every sink there should be two small valves, hot and cold. Under the toilet there should be one. These let you shut off one fixture without blacking out the whole house, which is what you want at eleven at night.

Test each one: clockwise until it stops, then back. You are looking for three things. Does it turn at all? Does the water actually stop? Does anything weep from the stem while you turn it?

A valve that fails any of those three needs replacing, and it is a small job done calmly on a Tuesday — or an expensive one done in a hurry. Old multi-turn valves are the usual culprits. A quarter-turn ball valve, which moves through ninety degrees and stops, is much more reliable and is what I fit when one needs changing.

The washing machine, the water heater, the fridge

Three more that deserve a look while you are at it.

The washing machine. Rubber supply hoses perish from the inside, and a burst washer hose delivers a remarkable amount of water very quickly. If yours are rubber and you cannot remember buying them, braided stainless hoses are cheap and are one of the best small purchases in the house. Turn the taps off when you go away for more than a few days.

The water heater. Know where its shutoff is and where its drain is. Do not work on it. A water heater is a licensed trade's job, and a bad one can be dangerous rather than just wet.

The fridge line. If your fridge makes ice, there is a small valve feeding it, usually behind the fridge or under the sink. Those plastic saddle valves fitted decades ago are a known weak point.

Write it down

Take a photo of each valve with your phone and one of the main shutoff, and keep them in an album. It sounds fussy. The first time you have to tell somebody over the phone where to turn the water off, it will not.

What this costs if you would rather not

Nothing — this one is yours to do, and it is the only entry on this site I would rather you did not pay for. If a valve fails the test, replacing it is usually done in the same visit as whatever brought me out in the first place.