It almost certainly happened once in your life: you turn on the shower and get a trickle, or you’re trying to fill a pot and watch it take twice as long as it should. Low water pressure is one of those problems that’s easy to dismiss until it isn’t.
Find out what’s causing itThe thing is, low water pressure in your house is almost never “just how it is.” It’s almost always a symptom. So, let’s see why your water pressure is weak and when it’s time to stop guessing and call a professional.
Before we try diagnosing a problem, you might want to know what normal water pressure is. In Canada, residential water pressure ranges from 275 to 550 kPa, which is roughly 40–80 PSI.
Here’s a better overview:
| Water Pressure | kPa | PSI | What You Notice |
|---|---|---|---|
| Low | Below 200 kPa | Below 30 PSI | Flow is weak, and appliances don’t perform properly |
| Below normal | 200–275 kPa | 30–40 PSI | Slower flow at showers, taps |
| Normal | 275–550 kPa | 40–80 PSI | Everything works as expected |
| High | Above 550 kPa | Above 80 PSI | Can stress pipes and appliances; may trigger leaks |
Short history
Trenchless sewer repair is not a new or experimental technology. Trenchless methods have been used in North America since the 1970s and have become the gold standard for sewer line repair in urban and suburban areas in Canada, where old clay and cast iron pipes are still everywhere.
Your Water Pressure Is Low? Find Out Why!
Is your water flow weak, uneven, or inconsistent? This 7-question quiz will help you figure out the possible reason behind it.
Low water pressure all of a sudden? Before you try to fix it yourself, figure out what’s causing it. Is it just a temporary issue or a sign of a bigger problem?
Cause #1
Low water pressure in older home what to check first? Yes, this is the number one culprit behind low water pressure in older Canadian homes, especially those built before the 1980s.
Why it happens:
What you notice: Water pressure in your home has been dropping gradually over the years, not suddenly. Moreover, water may be slightly discoloured.
Why it gets worse: Corrosion and scale continue to build up in pipes over time, leading to leaks and increased pressure issues.
Low water pressure in an older home? Pipes are the first thing to check. A plumber will inspect them with a CCTV camera to assess the condition of your water main lines.
Cause #2
Many Ontario homeowners wonder: “Why did my water pressure drop suddenly?” Even if your pipes are structurally sound and free of corrosion, they can still contribute to the problem.
Why it happens: In areas with hard water, minerals such as calcium and magnesium gradually coat the insides of pipes and fixtures. This buildup doesn’t happen overnight, it accumulates steadily over the years until you notice that the pressure loss is already significant.
What you notice: Chalky white or grey deposits around tap bases and showerhead outlets, or greenish staining near pipe connections. Your fixtures may also sputter or spray unevenly rather than flowing in a clean stream.
Why it gets worse: Limescale doesn’t dissolve on its own, so you’ve got to fix it yourself. If you don’t, the buildup that restricts flow can also stress pipe joints and lead to leaks.
Cause #3
Many homeowners ask why water pressure is low in the kitchen only. Even if you don’t see corrosion or mineral buildup, something can be physically obstructing the flow through your pipes.
Why it happens: There are many reasons for it, like debris from city maintenance, small objects in drains, sediment in older pipes, or tree roots, which can all restrict water flow.
What you notice: The pressure drops suddenly and might affect one area of your house or a single branch of your plumbing, rather than the entire system. You may also notice uneven flow.
Why it gets worse: Sediment, mineral buildup, or debris gradually accumulates, narrowing the pipe further and over time, this makes pressure drops more severe and can lead to leaks or broken pipes altogether if left unaddressed.
Clogs don’t need to fully block a pipe to affect pressure. Even a partial obstruction reduces flow to every fixture downstream. Unlike slow buildup from scale or corrosion, a sudden blockage can drop your water pressure quickly and without warning.
Cause #4
If your water pressure dropped suddenly, the possible culprit is a hidden leak in one of your pipes.
Why it happens: When water leaks through a crack or a pinhole, especially in copper pipes, less pressure reaches your taps. The tricky part is that many leaks are completely hidden, but they can run inside walls or underground in your supply line.
What you notice: The pressure drops with no obvious cause, and your water bill has increased suddenly. You may also hear running water when nothing is turned on.
Why it matters: A leak is never just a leak. It’s damaging your structure, leading to mould growth. Moreover, in Ontario winters, a leak near an exterior wall can freeze and cause a pipe burst.
Turn off every fixture in your home and watch your water meter. If it keeps moving, water is escaping where it shouldn’t be.
Cause #5
Most Canadian homes built in recent decades have a pressure reducing valve installed where the main water supply enters the house. Its job is to reduce high municipal pressure to a safe level for your home’s plumbing.
Why it happens: PRVs are mechanical, so they can wear out. They can also get stuck partially closed or be set too low during installation or a previous repair. The result is often low water pressure throughout your home, with no other obvious cause.
What you notice: Low pressure at every tap and fixture in your house at once. No single fixture or zone is worse than the others.
Why it matters: A faulty pressure regulating valve (PRV) can cause water pressure to go up and down unexpectedly. If you do not address the problem fast, it can lead to faster wear on pipe joints and connections to appliances.
Pressure-reducing valve replacement is one of the simplest solutions in this case and takes only minutes.
Cause #6
This is another reason why water pressure low only upstairs not downstairs. It may sound almost too simple, but it causes more service calls than you’d think, especially after recent plumbing work.
Why it happens:
Your home has a main shut-off valve where the supply line enters, as well as additional individual valves near sinks, toilets, and appliances. These valves should be fully open at all times and if they are not, you will experience low pressure throughout the whole house.
What you notice: In this case, the issue usually appears right after recent plumbing work or an appliance installation, or the pressure may be low at one fixture while everything else runs normally.
Why it gets worse: If you didn’t use valves for years, they can get stuck. In that case, don’t force them open. If you do so, you can break it, turning a simple repair into an emergency.
Cause #7
If your home shares a supply line with one or more neighbouring properties, then their water use directly affects yours.
Why it happens:
When multiple households draw water from the same supply simultaneously, your pressure drops. Basically, you’re competing for the same incoming water, and during peak hours, everyone loses a little.
What you notice: Pressure drops are predictable and tied to times when neighbours are likely to be using water heavily, like in mornings, evenings, and weekends. You use water as usual, but the pressure varies depending on what time of day it is.
Why it matters: Unfortunately, this isn’t an issue that goes away on its own. If the shared supply line is too small for all the homes using it, the problem usually gets worse as water demand grows. To solve it, consider installing a dedicated line.
If your water pressure drops mainly during peak times, install a dedicated supply line to ensure consistent pressure for your home.
The sad truth about low water pressure is that it is almost never a stable problem but a progressive one.
If you ignore it, then corroding pipes keep corroding. Scale keeps building up. Leaks keep getting bigger. The underlying condition that’s causing your low pressure today will cause worse pressure and likely more expensive damage tomorrow.
Sure, you will check first the shut-off valve under the sink or the showerhead for scale buildup, and those are reasonable first steps. But if you’ve done the basics and the pressure is still low, the problem goes deeper.
If every tap and fixture in your home has low pressure simultaneously, that means the problem might be in your main line, your PRV, or the municipal supply.
If you notice a sudden change in pressure, it almost always means a leak, a damaged line or a faulty valve. These need to be diagnosed properly before they cause even more damage.
If your home was built before 1980 and still has its original galvanized steel plumbing, it simply means that your pipes are approaching the end of their life.
Paying more than usual? That’s definitely a leak, and leaks cause damage far beyond the plumbing itself.
The majority of serious low water pressure issues in Canadian homes are caused by corroded pipes, hidden leaks, undersized supply lines, and root intrusion. An expert plumber offers a few solutions, depending on the culprit.
Solution #1
Many homes in Canada still have galvanized pipes, but over time, rust buildup can narrow them, reducing water pressure. In other cases, the lines may simply be old, cracked, or corroded.
What it targets: Corroded or broken pipes, hidden leaks, undersized supply lines, and root intrusion.
How it solves the problem: A plumber inspects your main supply line with a camera, finds the exact cause, and fixes it at the source. Most repairs can be done without digging up your yard if a plumber uses a trenchless method.
Why it’s usually the best solution: Fixing or replacing the main water line addresses the problem at its source. It restores full pressure to your entire home, solves hidden or long-term issues, and prevents repeated quick fixes that don’t last. In many Canadian homes with aging or corroded pipes, this is the most reliable, long-term solution.
Solution #2
You can’t remove years of mineral buildup with store-bought cleaners. When pipes are clogged from the inside, professionals use hydro-jetting to fully clear the blockage and restore proper flow.
What it targets: Limescale inside your pipes, debris or sediment, and biofilm buildup, as well as tree roots.
How it solves the problem: A plumber blasts high-pressure water through the affected pipes, fully clearing them.
Solution #3
If your pressure dropped suddenly and every tap in the house is equally weak, your PRV or main shut-off valve is the first thing worth checking. Both sit at the same entry point, and both are easy to overlook.
What it targets: Whole-house low pressure, pressure fluctuations, and issues caused by a stuck or improperly set PRV or main shut-off valve.
How it solves the problem: A plumber tests both the PRV and the shut-off valve at the main supply entry in the same visit. If either is worn out, set wrong, or seized, they replace it on the spot. And if neither turns out to be the culprit, the main water line behind them is almost certainly the source of the problem.
So, how to fix low water pressure? The problem is almost never “just how it is.” If you notice that something is wrong, then something really is. Moreover, if left alone, it tends to develop into something more expensive.
If your showers have felt weak for too long, and you want to know how to clean a shower head, then the sad truth is that it won’t fix the problem. The best you can do is not to wait for the problem to solve itself. It won’t. There’s no long-term DIY water pressure booster solution.
Call an expert plumber for low water pressure in Ontario. They will assess your fixtures and give you a clear picture of what’s actually happening in your home’s plumbing. And only then you do get a reliable solution.
