What you can actually control about water pressure in an apartment
Low water pressure in an apartment is usually caused by something outside your unit—a building-wide issue, a problem in the main line, or the way your building's plumbing is designed. That means many fixes require your landlord or building management, not you. But before you call them, there are three things you can check and adjust yourself: the shut-off valve under your sink, the aerator on your faucet, and mineral buildup in your pipes.
If those don't work, the problem is almost certainly in the building's water supply system or your landlord's responsibility to fix. Knowing the difference saves you time and frustration.
Key Takeaways
- Check the shut-off valve under your sink first—it should be fully open, and a partially closed valve is the easiest fix for low pressure in one room.
- Remove and clean the aerator (the screen at the faucet tip) because mineral deposits often block water flow without affecting pressure elsewhere.
- If low pressure affects your whole apartment, the problem is in the building's water supply or your landlord's responsibility, not something you can fix.
- Tell your landlord which faucets have low pressure and whether it happens all day or only at certain times, because that information helps them diagnose the real cause.
- Do not install a pressure-boosting pump without written permission from your landlord, because it can damage the building's plumbing system.
Check the shut-off valve under your sink
The shut-off valve is a small knob or lever on the water line that enters your apartment, usually located under the kitchen sink or in a cabinet near the main water entry. If this valve is not fully open, it will reduce water pressure to your entire unit or to one room.
Turn the valve counterclockwise (or pull the lever all the way out if it is a lever-style valve) until it stops. Do not force it. If the valve is already fully open, move to the next step. If turning it increased your pressure noticeably, you have found the problem—but mention it to your landlord anyway, because a partially closed valve sometimes indicates a maintenance issue they should know about.
Clean the aerator on your faucet
The aerator is the small screen at the tip of your faucet. Mineral deposits from hard water build up inside it and block the flow, making pressure seem low even though the water supply is fine. This is especially common in kitchens, where you use hot water more often.
Unscrew the aerator by hand (turn it counterclockwise) or use a wrench if it is stuck. Rinse it under running water and use an old toothbrush to scrub away white or brown deposits. If deposits are heavy, soak the aerator in white vinegar for 30 minutes, then scrub again. Screw it back on and test the pressure. If this fixes the problem, you are done. If pressure is still low at that faucet, the issue is deeper in the line and your landlord needs to investigate.
Identify whether the problem is building-wide or in your unit
Before you contact your landlord, determine whether low pressure affects one faucet, one room, or your entire apartment. This tells them where to look.
Test the pressure at your kitchen sink, bathroom sink, shower, and toilet fill valve (the small pipe that refills the tank). If only one faucet has low pressure, the aerator or a clog in that line is the likely cause. If pressure is low everywhere, the problem is in the building's main water supply, the line coming into your unit, or the pressure regulator that controls flow to your apartment. That is your landlord's responsibility to fix.
Also note the time of day: if pressure drops only during morning or evening hours when many people are using water, the building's supply may be undersized or the pressure regulator may need adjustment. If pressure is always low, the problem is more likely a leak or a regulator that is set too low.
When to contact your landlord
Contact your landlord in writing (email is fine) if pressure is low in multiple rooms or if cleaning the aerator did not help. Include the specific faucets affected, the time of day the problem occurs, and whether it started suddenly or has always been low. This information helps them decide whether to call a plumber or check the building's main shut-off and pressure regulator.
Your landlord is responsible for maintaining the water supply to your unit, including the main line, the pressure regulator, and any shared pipes in the walls. They are also responsible for fixing leaks that reduce pressure. You are responsible only for the aerators and shut-off valves inside your unit.
Do not install a pressure-boosting pump or any other device without written permission from your landlord. These devices can damage the building's plumbing system and may violate your lease or local plumbing codes.
Why apartment water pressure is different from a house
Apartments often have lower water pressure than houses because multiple units share the same water line, and the building's pressure regulator is set to balance supply across all units. A regulator that is set too low, or one that is failing, will reduce pressure throughout the building or in certain zones.
If your building is old, the main water line may be corroded or partially blocked, which reduces pressure over time. If your building is tall, water pressure naturally decreases on higher floors because gravity works against the flow. These are not problems you can fix, but they are problems your landlord can address by replacing the regulator, flushing the main line, or installing a pressure-boosting system for the whole building.
What not to do
Do not assume low pressure means low water volume. Pressure and volume are different: you might have plenty of water, but it is coming out slowly. Trying to "fix" this by installing a pump or modifying the shut-off valve can backfire and cause damage.
Do not ignore the problem if it affects multiple rooms or your whole apartment. Low pressure can indicate a leak in the building's main line, which wastes water and money and can damage the structure. Your landlord needs to know.
Do not run multiple high-flow fixtures at once (shower, washing machine, and dishwasher simultaneously) and then assume the pressure is permanently low. Pressure naturally drops when demand is high. Test pressure at a single faucet when no other water is running.
Frequently Asked Questions
Can I install a pressure booster pump myself?
No. Pressure booster pumps require professional installation and can damage your building's plumbing if not sized and installed correctly. They also may violate your lease or local plumbing codes. Ask your landlord in writing if they will install one for the whole building.
Why is my shower pressure low but my sink pressure is fine?
The shower line may have a clogged aerator or a flow restrictor (a small device that limits water use). Remove the showerhead, clean it with vinegar, and test again. If pressure is still low, the problem is in the shower valve or the line feeding it, and your landlord should inspect it.
Does water pressure change by time of day?
Yes. Pressure often drops in the morning and evening when many people in the building are using water at once. If pressure is normal at other times, this is normal behavior and not a maintenance problem. If pressure is always low, even late at night, contact your landlord.
What if my landlord says low pressure is normal for the building?
Low pressure is not normal if it prevents you from showering comfortably or filling a pot in reasonable time. Check your lease and local tenant laws—many places require landlords to maintain adequate water pressure. If your landlord refuses to investigate, contact your local housing authority or tenant rights organization.
Can a leak cause low water pressure?
Yes. A leak in the main line or in the walls can reduce pressure throughout your apartment or the whole building. If pressure dropped suddenly and you cannot find an obvious cause, ask your landlord to check for leaks. A leak also shows up as higher water bills or wet spots on walls or ceilings.