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Low Water Pressure Langley | Causes & Fixes

Low water pressure Langley? Check one tap or the whole house first. Seven common causes, what you can fix yourself, and when it's time to call a plumber.

GENERAL PLUMBING

Plumblink Crew

10/5/20264 min read

Adjusting a pressure reducing valve on a home water line to fix low water pressure in Langley

Low Water Pressure in Langley: 7 Causes and How to Fix Them

A shower that used to sting now barely rinses the shampoo out. Low water pressure rarely fixes itself, but the cause is usually one of seven things.

Two quick checks will narrow it down before you spend anything.

Start With Two Checks

One tap, or every tap? Turn on a few fixtures around the house, including an outside hose bib. If only one is weak, the problem is at that fixture. If they are all weak, the problem is at the supply: the main valve, the pressure reducing valve, the pipes or the street.

Hot, cold, or both? If only the hot side is weak, look at the water heater. If both are weak, the cause is upstream of the tank.

Note how it happened, too. A sudden drop points to a valve, a leak or municipal work. A slow fade over months points to buildup or a worn part.

1. A Clogged Aerator or Showerhead

The small screen on the end of a faucet catches grit and mineral scale. Unscrew it, rinse it, soak it in vinegar if it's crusty, and thread it back on. Showerheads clog the same way. This is the most common cause of one weak tap, and it costs nothing to fix.

Homes on well water in Aldergrove and the rural Township see it more often, because groundwater carries more minerals and iron than the Metro Vancouver supply. If you are cleaning screens every few weeks, water filtration deals with the cause.

2. A Valve That Isn't Fully Open

After a repair or a renovation, a shut-off often gets left half closed. Check the main shut-off where the water line enters the house, and the small stop valves under the weak sink or toilet. A lever handle should sit in line with the pipe. A round handle should be turned fully counter-clockwise.

One caution: old valves can seize or snap. If it won't turn with hand pressure, leave it alone.

3. A Failing Pressure Reducing Valve

Many Langley homes have a pressure reducing valve, or PRV. It's a fist-sized, bell-shaped brass fitting near the main shut-off. It brings street pressure down to a level your pipes and fixtures can handle. The BC Plumbing Code requires one wherever supply pressure can exceed 550 kPa (80 psi).

PRVs wear out. The inlet screen clogs or the internals fail, and pressure drops through the whole house at once. The City of Langley's own advice for low pressure is to check the PRV screen first.

A PRV can be adjusted, but turning it up is the wrong fix if the real cause is a narrowed pipe. Pressure above 80 psi is also hard on water heaters, washer hoses and faucet cartridges. Have the pressure measured with a gauge before anyone touches the adjusting bolt.

4. Hot Side Only: The Water Heater

If the cold runs strong and the hot is weak, check that the valve on the cold inlet pipe above the tank is fully open. If it is, sediment in the tank or a clogged outlet is the likely cause.

Weak hot water is not the same problem as hot water that runs out. For that one, see why you keep running out of hot water. On a tank past ten years old, it can make more sense to price a replacement than to chase the fault.

5. Old Galvanized Steel Pipes

Homes built before about 1970 were often plumbed in galvanized steel. It rusts from the inside, and the opening gets narrower every year. The pattern is pressure that has faded for years, is worst upstairs, and sometimes runs brown for a second when you first open the tap.

Cleaning aerators helps for a week. The lasting fix is repiping, which is not a small job, so have the pipe confirmed before you commit. If your home has grey Poly-B instead, that is a different problem with its own insurance issue.

6. A Hidden Leak

Water that escapes before it reaches the tap lowers pressure everywhere. If your home has a water meter, shut off every tap and appliance and watch it. If the dial still moves, water is going somewhere.

Other signs are a soggy patch of lawn between the street and the house, the sound of running water with everything off, or a bill that jumped. Leak detection finds the spot before anyone opens a wall.

If the leak is in the buried line between the property line and the house, that pipe belongs to the homeowner, not the municipality. It can often be replaced without trenching the yard.

7. It's Not Your House

Sometimes the supply itself is low. The Township and the City both flush water mains on a schedule, and pressure dips while crews are in your area. A main break does the same.

Ask a neighbour. If they are low too, call Township of Langley Engineering at 604-532-7300 or City of Langley Operations at 604-514-2910 before you call a plumber.

What You Can Fix, and When to Call

Worth trying yourself:

Cleaning aerators and showerheads
Opening a valve that turns freely
Checking with a neighbour
The water meter test

Time to call a plumber:

Every tap is weak and the valves are open
The PRV needs testing or replacing
You see any sign of a leak
Pressure is fading and the water runs brown
Pressure dropped suddenly and the neighbours are fine

Frequently Asked Questions

What is normal water pressure for a house? Most homes run well between about 45 and 60 psi. The BC Plumbing Code caps it at 80 psi (550 kPa), which is why homes on higher-pressure streets have a pressure reducing valve.

Why did my water pressure drop suddenly? A sudden drop through the whole house usually means a half-closed valve, a failed pressure reducing valve, a leak, or municipal work on the water main. Check with a neighbour first.

Can I adjust my pressure reducing valve myself? There is an adjusting bolt on top, but without a gauge you are guessing. Too much pressure is hard on your water heater, hoses and fixtures. Have the pressure measured first.

Why is only my hot water pressure low? The problem is at the water heater: a partly closed inlet valve, sediment in the tank, or a clogged outlet. Cold water running strong rules out the main supply.

Who do I call about low water pressure in Langley? If your neighbours are low too, call the municipality: Township of Langley Engineering at 604-532-7300 or City of Langley Operations at 604-514-2910. If it's only your house, call a plumber.