How To Fix A Running Toilet: Simple Solutions Before You Call A Plumber

A constantly running toilet isn’t just an annoyance—it can waste a lot of water daily, leading to higher bills and potential plumbing issues. Fortunately, running toilets can be repaired quickly and easily. So, before you call upon our professionals, follow our expert guide to diagnose and fix your running toilet.

Still, if the problem persists, don’t worry. Our experts at Happy Dog Plumbing & Heating are always here to help. Just call us on 02086822244 or email hello@happydogplumbing.london to book a professional repair.

“Get reliable service and expert solutions from Happy Dog Plumbing & Heating to keep your home running smoothly.”

Why Is Your Toilet Running?

A toilet that won’t stop running usually has a problem inside the toilet tank. The issue often comes from one of these components:

Toilet flapper replacement: The flapper is a rubber seal that controls the water flow from the tank to the bowl. A worn-out flapper can cause continuous water leaks.
Toilet float: The float determines how much water fills the tank. If it’s too high, water spills into the overflow tube, keeping the toilet running.
Toilet valve issues: The fill valve regulates the water entering the tank. If it’s faulty, the water won’t shut off properly.
Toilet handle problems: A loose or stuck handle can keep the toilet flushing, preventing it from resetting after each flush.
Water supply valve: If the shut-off valve isn’t working correctly, it may affect the water flow in the toilet, causing it to keep running.

By identifying the problem, you can use DIY toilet repair methods to fix it without calling a plumber.

DIY Steps To Fix Or Repair A Running Toilet

Tools You Need For DIY Toilet Repair

Before you start fixing your running toilet, gather the necessary tools to make the job easier. Here’s what you’ll need:

Adjustable spanner: This tool helps loosen and tighten nuts, especially with the water supply valve and toilet mechanism.
Screwdriver: Needed to adjust the toilet float or secure a loose toilet handle.
Pliers: Helps with gripping and turning parts like the toilet flapper chain or fill valve components.
Bucket and towels: These catch any water spills while working inside the toilet tank or handling the water flow.
Replacement parts – Depending on your diagnosis, you may need:

Toilet flapper replacement (if the flapper is worn out)
Fill valve replacement (if the toilet isn’t filling properly)
Toilet float (if the float is damaged or malfunctioning)
Toilet handle (if the handle is broken or loose)

Now that you have your tools ready let’s move on to the step-by-step guide for DIY toilet repair!

Step 1: Turn Off The Water Supply

Before you begin any repairs, locate the water supply valve (usually found behind the toilet) and turn it clockwise to shut off the water. This will prevent water from flowing while you work.

Step 2: Remove The Toilet Tank Lid

Carefully remove the toilet tank lid and place it on a flat surface. Be gentle, as the lid can be fragile.

Step 3: Check The Toilet Flapper

The toilet flapper is a rubber stopper at the bottom of the tank. It lifts when you flush, allowing water to flow into the bowl. If the flapper is old, cracked, or not sealing properly, water leaks continuously, causing the toilet to run.

How to replace the toilet flapper?

Turn off the water supply.
Drain the tank by flushing the toilet.
Unhook the old flapper from the chain and remove it from the pegs.
Install the new toilet flapper, ensuring it seals the flush valve properly.
Reconnect the chain and ensure it has slight slack—not too loose or tight.
Turn the water back on and flush to test.

If the running toilet repair is successful, your toilet should stop running once the tank is refilled.

Step 4: Adjust The Toilet Float

The toilet float controls the tank’s water level. If it’s set too high, excess water spills into the overflow tube, keeping the toilet running.

How to adjust the toilet float?

If your toilet has a ball float, bend the metal arm slightly to lower the water level.
If your toilet has a cup float, use a screwdriver to adjust the float’s height by turning the screw on the fill valve.

Flush the toilet and check if the water stops running. If not, you may need to inspect other parts.

Step 5: Inspect The Fill Valve For Leaks

A faulty fill valve can cause continuous water flow into the tank, leading to a toilet flushing system issue.

How to fix a toilet fill valve?

Turn off the water supply valve and flush the toilet to empty the tank.
Disconnect the water supply line from the fill valve.
Remove the old fill valve and install a new one according to the manufacturer’s instructions.
Reconnect the water supply line and turn the valve back on.
Flush the toilet and check if the water stops running.

If your toilet valve issues persist, it may be time to call a professional plumber.

Step 6: Check The Toilet Handle And Chain

A stuck or loose toilet handle can prevent the flapper from sealing properly.

How do you fix a loose or stuck toilet handle?

Remove the toilet tank lid and check if the chain is tangled or tight.
Adjust the chain length so there is a little slack.
If the handle is loose, tighten the mounting nut inside the tank.

Test by flushing the toilet to ensure the handle lifts and resets properly.

Preventing Maintenance Tips For Future Toilet Problems

Along with the above DIY running toilet repair steps to avoid toilet leaks from the tank and other issues, follow these toilet maintenance tips:

Regularly check the toilet flushing system for signs of wear.
Replace the toilet flapper every few years to prevent leaks.
Keep the toilet float properly adjusted to avoid excess water flow.
Clean the toilet mechanism to prevent buildup that can cause flushing problems.
Test the water supply valve occasionally to ensure it works properly.

Following these DIY plumbing solutions allows you to keep your toilet running efficiently and avoid costly repairs.

When To Call A Plumber?

While most toilet tank repair tasks can be handled with home repairs, some problems require professional help. Call a plumber if:

The toilet mechanism is damaged beyond simple fixes.
There are leaks around the base of the toilet.
The water supply valve won’t shut off.
The toilet still runs after trying these DIY toilet repair

If you need professional assistance, Happy Dog Plumbing & Heating is here to help.

Happy Dog Plumbing & Heating: Your Go-To Experts For Running Toilet Repair

Happy Dog Plumbing & Heating boasts over 50 years of combined experience. Our team of expert plumbers has helped countless homeowners in South London quickly diagnose and fix plumbing issues, including running toilets.

We are certified professionals trained to handle all toilet repairs, from replacing worn-out flappers and faulty fill valves to fixing water supply issues. Whether a minor adjustment or a complete replacement, our team ensures long-lasting solutions with top-quality parts and expert workmanship. Plus, all our repairs come with a 12-month workmanship guarantee, giving you peace of mind that your plumbing is safe.

If your toilet is still running despite your DIY efforts, don’t hesitate to call us. We offer fast, reliable service with upfront pricing—no hidden fees, just honest, high-quality plumbing solutions.