How to Solve Low Water Pressure in the House?

What Is Normal Water Pressure?

A healthy water pressure for your home is between 40 and 60 psi, and most plumbers agree that 50 to 60 psi is the optimal range. Anything above 80 psi runs too high and wears out pipes and fixtures. Pressure begins to drop below 50 psi, particularly in homes that have two bathrooms or a multi-head shower.

Pressure and flow are two different things. Pressure is a force that pushes water through the pipelines (psi). Flow refers to the volume of water flowing to the tap. Even with good pressure, water can come out as a trickle from an obstructed fixture. It is important to be aware of the difference.

Pressure testing takes just a few minutes. Pressure gauges are available at most hardware stores in the GTA for approximately 10 to 15 dollars. Screw it onto an outdoor hose bib or the laundry cold-water bib, completely open the tap and read the dial. In Toronto, the City checks formal low-pressure complaints by measuring flow at the meter. At least 7 L/min is considered acceptable, while less than 7 L/min is below the acceptable limit.

Is It One Fixture or the Whole House?

The best way to rule out a cause is to determine how far the problem reaches. Open the kitchen faucet, then a bathroom faucet, the shower, and an outside faucet.

If there is weak flow, there is one fixture pointing to it. It’s typically caused by a clogged aerator, a showerhead that’s blocked or a half-closed valve underneath the sink. Low flow at all of the upstream taps, towards the main valve, the pressure regulator, the service line, a leak, or towards the city valve supply.

Also, do a hot-against-cold test. A low cold pressure throughout the house indicates a problem with the main, regulator, or supply. If there is only low pressure on the hot side, it suggests that there may be sediment in the water heater, and a good flush should resolve that issue.

Common Causes of Low Water Pressure

Once you know how far the problem reaches, these are the causes to work through, from the simplest to the most involved.

1. Clogged Aerators and Showerheads

Minerals and limescale can build up on the little screens inside taps and showerheads. Toronto’s Lake Ontario-sourced water has relatively low mineral levels, so water hardness is not usually a city-wide concern; however, deposits can still collect on fixtures. Hardness may differ by municipality in the greater GTA. Unscrew the aerator or showerhead, soak it overnight in a mix of half water and half white vinegar, rinse it, and put it back. This one step will resolve most one-fixture issues.

2. A Partly Closed Main or Meter Valve

The main shut-off valve is located in the basement on the foundation wall just before the water meter and should be kept open. The meter valve also counts. If the handle is parallel to the pipe, the valve is open. A valve left half-closed after recent plumbing work throttles the flow to the whole house, so start here if your low-pressure lines are up for repair.

3. A Failing Pressure Regulator

A lot of houses in the GTA have a bell-shaped pressure regulator close to the main shut-off. Pressure that ends up as a trickle or is higher than 80 psi can be caused by sediment or a worn spring inside. A gauge test determines if the regulator is reading true or not. A licensed plumber can swap the unit in about an hour. Not all households have one available, so be sure to ask first.

4. Corroded or Undersized Pipes

Inside the walls of older Toronto homes is a common culprit. Galvanized steel pipes rust inwards, and the corrosion eventually narrows the pipe, reducing its flow. Copper lines can collect scale over the years. Homes built before the mid-1950s may still have lead service lines, and the City estimates just under 16,000 City-owned lead water service pipes remain. Many of the older homes also have a half-inch main that is too small to handle the modern plumbing fixtures.

If the water is discoloured and clears up after a few seconds or if the flow is weak at all taps, then it points to aging pipes. The permanent solution is to repipe or upgrade the water service to three-quarter-inch or one-inch copper, PEX or HDPE. Trenchless replacement requires minimal excavation and the City of Toronto provides rebates for replacing lead lines.

5. Hidden Leaks

A leak will cause water to escape from your fixtures and lower the water pressure throughout the house. Test for one at the meter. Close all the taps and appliances, record the meter reading, wait 2 hours and check again. If water moves anywhere, it’s escaping somewhere. A climbing water bill, damp spots, stains and mould all go in the same direction.

6. Municipal Supply and Peak Demand

Sometimes the problem is not within the property boundary. A break in a water main, work on hydrants, nearby construction work, or a change in valves can reduce the pressure for the entire street. Toronto has more than 6,100 km of watermains, and the City reports an average of 1,100 watermain breaks annually since 2016. Pressure can also be affected by heavy usage around the neighbourhood from 6 to 9 in the morning and 6 to 9 in the evening. Check with neighbours first. If their pressure drops too, call 311, and Toronto Water can check the pressure on the street and at your meter.

7. Shared Lines and Too Many Fixtures at Once

A shared service line serves more than one house, therefore a neighbour’s shower can lower your flow for a few minutes. If you run the dishwasher, the laundry and a shower simultaneously, then you’ll divide the supply up too. This is a matter of volume, not fault and spacing out the heavy water use typically resolves it.

8. A Partly Frozen Pipe in Winter

Cold weather adds a seasonal cause in the GTA. A partially frozen pipe restricts water flow, and a completely frozen pipe blocks water flow. Exterior walls and pipes in unheated areas are the most vulnerable. Our guide on preventing and thawing frozen pipes covers the fix in detail.

How to Fix Low Water Pressure Step by Step

Follow this sequence and you will solve most low-pressure issues or get to the point where a plumber will come in.

1. Test the pressure with a gauge. If the reading is below 50 psi, the problem is confirmed.
2. Test to see if the weak flow is reaching one fixture or all fixtures in the house, and then test hot with cold.
3. Clean the aerators and showerheads with a white-vinegar soak.
4. Ensure main shut-off and meter valves remain open.
5. Check the pressure regulator, or have a plumber test it.
6. Check for a leak using the 2-hour meter test.
7. Ask your neighbours, and call 311 if the whole street is affected.
8. For old galvanized or lead lines, plan a repipe or a water-service upgrade.
9. For a supply that stays consistently low, ask a licensed plumber about a booster pump.

Can a Booster Pump Increase Water Pressure?

A booster pump will only increase the pressure if the water pressure at your home is constantly low. It will not cure a clogged aerator, a hidden leak, or a corroded pipe; diagnose the cause first, and treat the pump as a last resort.

A booster pump earns its place in a few situations: a confirmed low municipal supply, a home on higher ground, a multi-story house, or a household that runs several fixtures at once. A pressure tank is used in conjunction with the pump to maintain pressure. Brands such as Grundfos and Salamander make compact home boosters for most homes in the GTA. Let the licensed plumber do the sizing and installation work, as this is well beyond do-it-yourself.

When Should You Call a Licensed Plumber?

There are some low pressure problems that pass a quick fix. Call a licensed plumber when any of these apply:

• Opening valves and cleaning fixtures will not restore the flow.
• Your water runs rusty or discoloured, or you suspect galvanized or lead pipes.
• The meter test indicates a hidden leak.
• Your pressure regulator is inaccurate or continually fails.
• The house’s water pressure is very low, and you need to install a booster pump.

Everest Drain & Plumbing is open 24/7 in the GTA and has been fixing low water pressure since 2013. We have licensed employees with trucks equipped with all the tools needed to diagnose the problem and repair it, whether it’s a clogged line or a complete water-service upgrade. Call (416) 383-7378 for help.

Water Pressure Help in Toronto and the GTA

Low water pressure is not a condition that will correct itself and it’s not one that will ruin your week either. Test your pressure, check whether the problem is one fixture or the whole house, and work through the simple fixes first. If the cause is more serious, the proper repair will restore your flow for good.

Everest Drain & Plumbing has kept water moving in Toronto and GTA homes since 2013. If it’s a hidden leak, an upgrade to your water services, or weak pressure, call our licensed team anytime at (416) 383-7378.