In my years working across homes, rentals, and renovations, I’ve seen one truth repeat itself: plumbing problems don’t usually arrive with a dramatic flood or a burst pipe. Most start quietly. A drip under the sink. A toilet that won’t stop refilling. A habit that seems harmless until the bill arrives.
Whether you own your home, rent a unit, or manage an older property, it’s easy to miss the signs. Water waste and slow damage add up over time. That’s why your monthly bill might feel high, even when everything looks normal on the surface.
Here are twelve plumbing mistakes that I’ve seen cost people more than they expected — and advice to help you avoid them.
It’s easy to walk past a dripping tap. The sound might not even register anymore. But each drop adds up. A slow leak can waste thousands of litres over a year. That’s water you never used, but still paid for.
What’s worse, the leak often spreads to surrounding fittings. A small drip now can eventually damage the tap body, stain the sink, or rust nearby fixtures. Fixing it early is fast and cheap. Waiting often means replacing parts that weren’t worn out in the first place.
Don’t let a quiet leak quietly drain your wallet.
A toilet that never stops filling isn’t just annoying. It can waste more than 200 litres a day. That’s like running your washing machine four or five times without putting in any clothes.
Toilet leaks are often silent. The internal mechanism wears down, allowing water to constantly flow into the bowl. The tank tries to keep up by refilling endlessly. Most people notice the sound only occasionally and assume it’s harmless.
It isn’t. If your toilet runs longer than necessary after flushing, it’s time to get it checked. The fix is usually simple — and far cheaper than letting it run unchecked.
Many people think that turning the tap harder will make it stop dripping. But overtightening can damage the washers, crack the seal, and even deform the internal threads.
Over time, these stresses create slow leaks that are hidden behind walls or under sinks. Once that happens, you’re not just looking at a washer replacement — you’re looking at water damage, rot, or mildew.
Use firm but moderate pressure when turning off taps. If it continues to drip, the fix lies inside, not in force. Knowing when to stop turning is part of good plumbing maintenance.
Everyone loves a strong shower. But if your water pressure is too high, it puts constant stress on your pipes, joints, and appliances.
High pressure wears out valves and connectors prematurely. It increases the risk of leaks, especially in older plumbing systems that weren’t built for it. You might not notice the damage until it’s too late.
A pressure-limiting valve can help regulate flow and prevent long-term stress. If your taps or showers blast rather than stream, it’s worth having the pressure tested. Small changes here help prevent big repair jobs later on.
It might be liquid when it goes down. But grease cools and solidifies inside your pipes, sticking to the walls and attracting food scraps. Over time, this forms blockages that don’t shift with boiling water or store-bought cleaners.
Grease is one of the top causes of blocked kitchen drains. Even small amounts build up if it becomes a habit. And when the blockage gets bad enough, you’re facing an urgent and messy call-out.
Pour leftover grease into a container and bin it once it hardens. The extra step saves your drains and your budget.
There’s nothing wrong with trying a small repair. But I’ve seen jobs where the “fix” made things worse. Tape where a seal was needed. Glue on plastic fittings. Parts forced together with no thread support.
Without the right tools or knowledge, DIY repairs often shift the problem to another part of the system. A cracked fitting or over-tightened joint might hold temporarily, only to leak later.
If you’re unsure, pause before diving in. A proper repair avoids rework, damage, or emergency costs when the temporary patch fails.
Outdoor taps are out of sight and often out of mind. But when they’re left slightly open — especially with a hose still attached — water can trickle out all night or while you’re at work.
In colder months, this can lead to frost damage in the tap or connecting pipes. In warmer months, it’s just wasted water that adds to your bill.
Make it a habit to turn outdoor taps off tightly after use. Check for leaks or drips regularly. A ten-second task can prevent litres of waste every day.
Some packaging says “flushable,” but that doesn’t mean safe. Wipes, paper towels, cotton pads, and sanitary items might disappear from view — but they don’t break down like toilet paper.
These items clog pipes and create blockages deep in your plumbing or local sewage system. In units and older homes, the problem often backs up quickly.
Keep a bin in the bathroom and use it. It’s far cheaper than paying for drain clearing, especially if the blockage causes overflow or damage.
Most people don’t think about their plumbing until something breaks. But a yearly check-up can catch worn valves, small leaks, corrosion, or slow drains long before they turn into emergencies.
Annual maintenance also helps you spot ageing parts that might affect water quality or energy efficiency. In particular, homes with older systems may benefit from checks on hot water cylinders or external pipes.
Good plumbing maintenance pays for itself. A small fee today prevents costly damage or disruption later on.
A worn-out washer costs very little. But ignore it, and you’ll deal with a constant drip that wastes water all day, every day. Over time, that adds real cost to your water bill.
Replacing washers is one of the simplest plumbing tasks. But many households delay it or try to tighten the tap instead — which, as we’ve covered, creates new problems.
If you hear a drip or feel resistance in a tap, a washer swap is probably overdue. Get it done early, and avoid watching money go down the drain.
That sound of water struggling to drain, or gurgling in the pipe, is a warning. It’s often caused by trapped air, partial blockages, or poor venting. Left unchecked, it can turn into a full blockage.
These issues also stress your plumbing system. Water that drains too slowly can cause backflow, leaks at joints, or pressure build-up in older pipes.
The sooner you act, the easier it is to fix. A simple clean-out now is always better than waiting for water to overflow.
Many costly plumbing jobs I’ve attended could have been avoided if the owner had acted earlier. A small stain under the sink. A soft spot in the wall. A strange odour near a drain.
These signals often mean water is leaking behind the scenes. Over time, this leads to structural damage, rot, mould, or electrical risks — all from a leak that might have started with a pinhole crack or loose fitting.
Don’t wait until there’s water on the floor. If something seems off, it’s worth getting checked. Plumbing doesn’t need to fail loudly to be expensive.
When it comes to plumbing, it’s not usually one big mistake that costs you. It’s a handful of small ones that go unnoticed. A drip here. A delay there. A shortcut that was meant to be temporary but became permanent.
These issues slowly push your water bills higher. They wear out systems that should last for years. And when they finally fail, the damage often spreads.
Whether you’re keeping an eye on your own home, looking after a rental, or managing a multi-unit property, plumbing awareness goes a long way. Fixing small problems early is always cheaper than reacting too late.
Matthews Plumbing & Gasfitting works with homeowners, landlords, and busy families to catch issues early, keep systems working efficiently, and handle repairs with care. From general maintenance to full hot water cylinder replacement, our work focuses on saving you time, money, and stress.
When water starts costing more than it should, we’re here to help.
