Home plumbing guide

Low water pressure in your house – what to check first

DIY-friendly steps Plumber-ready checklist Last updated:

If your whole house suddenly has weak water pressure, it doesn’t always mean a major plumbing disaster. In many cases, it’s a valve, filter, or local issue you can find in a few minutes before you pay a plumber’s hourly rate.

This guide walks through the simple, safe checks most homeowners can do themselves – and what to write down if you do end up calling in a pro.
Check my low water pressure issue (coming soon)

1. Start with the symptoms

Answer these first – they tell you where to look:

  • Whole house or just one area? (e.g., only upstairs, only one bathroom, or every tap)
  • Hot, cold, or both? If hot only, it may be a water heater issue.
  • Sudden change or slowly getting worse?
  • Any work done recently? (plumber, city, reno)

2. Quick checks (no tools needed)

Before you touch valves or plumbing, run through these quick checks:

  1. Check multiple fixtures.
    Test at least:
    • One sink on the main floor
    • One shower/tub
    • An outside hose bib (if available)
  2. Check both hot and cold.
    If cold is strong but hot is weak, the problem is likely at or after the water heater.
  3. Look at faucet aerators.
    If one or two taps are much weaker than others, unscrew the end of the faucet (aerator) and check for debris or scale.
If pressure is low at every fixture, hot and cold, think main valve, pressure regulator, filters, or supply issues – not just one faucet.

3. Main shutoff & pressure regulator

The main shutoff valve and pressure regulator (if your home has one) are common choke points.

Main shutoff valve

  • Find the main valve where water enters the house (near the meter or foundation wall).
  • For a handle-style valve, make sure it’s turned fully counter-clockwise.
  • For a lever-style ball valve, the handle should be in line with the pipe, not across it.

Pressure-reducing valve (PRV)

Some homes have a bell-shaped pressure regulator.

  • If it’s very old, corroded, or was recently adjusted, it may be restricting flow.
  • Don’t crank it randomly – note its condition and mention it to a plumber if needed.
Avoid taking apart the main valve or PRV unless you know exactly what you’re doing. Small mistakes here can cause major leaks.

4. Whole-home filters & softeners

If your house has a whole-home sediment filter, carbon filter, or water softener, a clog here can create low pressure everywhere.

  • Find any filter housing on the main line (often a clear or opaque canister).
  • Look for a “bypass” lever on water softeners and try switching to bypass temporarily.
  • If you know how, shut water off and replace the filter cartridge – they often clog long before people remember to change them.

Useful items for low water pressure issues

  • Replacement whole-home sediment filter cartridges
  • Basic water pressure gauge (screws onto a hose bib)
  • Hose bib splitter with shutoff valves
  • Pressure booster pump kit (for long-term upgrades)

Later, once this page gets real traffic, this box will include carefully chosen affiliate links – not random stuff.

5. Is it just you – or the whole area?

Before you spend money inside your home, ask:

  • Do nearby neighbours also have low pressure right now?
  • Did you notice road work, hydrant flushing, or city notices about water?
  • Is pressure especially low at certain times of day (e.g., early evening when everyone is using water)?

If multiple homes are affected, call your water utility first. They may already know of an issue with the main line or pumps.

6. Long-term pressure boost options

If your city supply is just weak but stable, there are ways to improve things inside your home:

  • Booster pump + small pressure tank to increase and stabilize pressure.
  • Upgrading old, narrow galvanized pipes to modern copper or PEX.
  • Replacing restrictive showerheads and aerators with higher-flow models (where legal).

7. When to call a plumber

Stop DIY and call a licensed plumber if:

  • Pressure dropped suddenly and hasn’t recovered after basic checks.
  • You see signs of leaks, wet spots, or unexplained water usage.
  • Only your home is affected, neighbours are fine, and main valve/filter checks didn’t help.
  • Your PRV, main valve, or main line looks corroded or damaged.

Details to note before you call:

  • When you first noticed the pressure drop.
  • Which fixtures are affected (all vs specific).
  • Any recent plumbing or city work.
  • Any filter/softener maintenance you’ve just done.

In the future, FixifyHome will include a simple “Check my low pressure issue” tool. It’ll walk you through these questions and prepare a clean summary for a plumber or your city.

8. Low water pressure – FAQ

Why is the water pressure low in my whole house?
Common causes include a partially closed main valve, clogged whole-home filter, faulty pressure regulator, or an issue with the city’s supply.

Who is responsible for fixing low water pressure?
You’re usually responsible for anything from the meter into your house. The city or water utility is responsible for supply issues on their side and in the street.

Can a clogged filter cause low pressure?
Yes. Whole-home filters can clog enough to noticeably drop pressure at every tap.

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