Why Is My Toilet Constantly Running?

Updated: November 27, 2025

If you’ve noticed a toilet constantly running in your home, you’re not alone — and you’re right to pay attention. That steady trickle isn’t just background noise; it can waste hundreds of gallons a day and drive up your water bill. The good news: most constant toilet running issues are easy to diagnose and often inexpensive to repair. As your Best Friend in Home Services, B. Carlson Heating, Air Conditioning & Plumbing has been helping Albuquerque and surrounding communities since 1971 fix their constantly running toilets. We’ll walk you through why the problem matters, how to find the cause, a safe and constantly running toilet fix you can try, and when our plumbers should step in to make sure everything shuts off the way it should.

Albuquerque’s high desert climate is tough on home systems. Dry air and mineral sediment can wear out rubber parts and valves faster than you’d expect. If you’re hearing a quiet hiss or seeing a slow refill after every flush, this guide will help you stop a continuous running toilet and protect your fixtures. And if you’d rather skip the DIY, our licensed plumbers in Albuquerque will be there fast with dependable solutions that last.

Why Constant Toilet Running Matters

It’s easy to ignore a soft sound coming from the bathroom, but a toilet constantly running means the tank is refilling over and over to make up for water escaping somewhere inside. Even a slow leak can move hundreds of gallons a day — and that extra use shows up on your bill. In our region, where water conservation matters and utility costs are top of mind, a continuous running toilet is more than a small annoyance.

There’s also wear and tear to consider. Tank parts like the flapper, fill valve, float, and seals are built to run in short bursts, then rest. With constant toilet running, rubber loses flexibility, seals deform, and settings drift. Over time, the toilet becomes less efficient, and you may notice odd behavior: intermittent refills, a faint hiss, or weak flushes. Some leaks are “silent,” with no water on the floor or loud sound. If the flapper doesn’t seal tightly, water slips from the tank into the bowl and the fill valve kicks on to top it off. You might spot a trickle into the overflow tube or hear refilling every few minutes.

The upside is simple: most causes are minor and fixable at home. A careful look inside the tank and a few small adjustments can solve a constantly running toilet fix in minutes. And if the issue points to a part better handled by a pro, B. Carlson’s plumbers can make a precise repair and ensure the whole system is calibrated correctly.

Common Causes of a Toilet That Keeps Running

Most running toilets trace back to a handful of familiar issues inside the tank. Understanding how each part should work helps you find the culprit quickly.

• Worn or warped flapper: The flapper seals the opening at the bottom of the tank after a flush. Age, mineral deposits, or warping can prevent a tight seal, letting water leak into the bowl and causing constant refills.
• Chain length problems: If the chain from the handle to the flapper is too short, the flapper can’t seat fully. If it’s too long, it can tangle or slide under the flapper, holding it open just enough to leak.
• Malfunctioning fill valve: The fill valve controls incoming water. Sediment buildup or worn internal seals can keep it from shutting off. You might see water trickling into the overflow tube or hear a steady refill.
• Incorrect float height: The float sets the shutoff level. If it’s too high, water spills into the overflow tube and the tank never rests. Too low, and flushes can be weak and cause repeated attempts.
• Damaged flush valve seat: The flapper needs a smooth surface to seal. Nicks, pitting, or scale on the flush valve seat can let water leak even with a new flapper.
• Mispositioned refill tube: The small tube that directs water into the overflow should rest just above the opening. If it sits too deep, it can siphon water into the bowl and lower the tank level, keeping the fill valve cycling.

These issues often overlap. A high float setting can magnify a minor flapper leak, and a refill tube placed too deep can make a healthy fill valve look faulty. A slow, methodical look inside the tank usually reveals what’s really going on with your continuous running toilet.

Step-by-Step: Troubleshoot a Constantly Running Toilet

You won’t need special tools to diagnose most issues. Leave the water on so you can watch parts move and listen for changes. Work gently with plastic components to avoid cracks or misalignment. If you see corrosion, loose tank hardware, or anything that seems unstable, pause and contact B. Carlson.

1. Remove the tank lid: Lift the porcelain lid with both hands and set it on a towel. Identify the parts: flapper, chain, flush valve seat, fill valve, float, overflow tube, and refill tube.
2. Flush and observe: Watch the flapper rise and fall. Does it land squarely on the seat? Does the chain snag? The float should rise with the water and stop the fill valve at the right level.
3. Test the flapper seal: After the flush, if you hear a faint hiss or see ripples in the bowl, gently press the flapper down with a spoon handle. If the sound stops, the flapper likely isn’t sealing and may need cleaning or replacement.
4. Check chain slack: The chain should have a small amount of slack—about half an inch—when the flapper is closed. Too tight and it holds the flapper open; too loose and it can slide under or snag.
5. Confirm float height: On cup-type floats, the cup rides up the fill valve; on ball floats, it sits at the end of a rod. Water should stop about an inch below the top of the overflow tube. If water reaches the top or spills into the overflow, the float is set too high.
6. Watch the overflow: If water keeps trickling into the overflow after the tank looks full, either the float is too high or the fill valve isn’t shutting off completely.
7. Listen for patterns: A constant soft hiss often points to a flapper or seat leak. Intermittent refills every few minutes suggest a slow leak lowering the tank level over time.

These checks take only a few minutes and help you decide if a constantly running toilet fix is within reach. If simple adjustments don’t solve your continuous running toilet, you’ve already narrowed the likely cause — useful for a DIY repair or a professional visit.

DIY Fixes You Can Safely Try

Most issues respond to straightforward, low-cost fixes. Change one thing at a time and test after each adjustment. Avoid over-tightening plastic hardware to prevent cracks.

• Adjust the chain: Unhook and reattach the chain so there’s slight slack when the flapper is closed. Test several flushes to confirm the flapper closes cleanly and the chain doesn’t snag.
• Clean and reseat the flapper: Turn off the water at the shutoff valve if you prefer. Lift the flapper and wipe the underside with a cloth. Clean the flush valve seat with a non-abrasive pad to remove mineral film. Make sure the flapper’s ears or ring are seated correctly on their posts.
• Set the float height: For cup-style floats, slide the adjustment clip to lower the shutoff level. For ball floats, carefully bend or adjust the rod downward. Aim for a water line about an inch below the top of the overflow tube. Flush and verify the fill valve stops promptly.
• Reposition the refill tube: The refill tube should rest just above the overflow opening, not submerged. Use a clip to keep it steady so water drips into the overflow without creating a siphon.
• Replace the flapper: If the flapper is brittle, warped, or visibly worn, replace it. Most universal flappers fit standard valves, but matching size and style gives the best result. Remove the old flapper, clean the seat, attach the new one, and adjust the chain.

These fixes cover the most common reasons for a toilet constantly running and often resolve a continuous running toilet quickly. If your checks point to a failing fill valve, avoid complex internal rebuilds unless you’re comfortable shutting off water, handling supply connections, and seating gaskets correctly. An incorrect installation can lead to persistent overfilling or leaks. When in doubt, our licensed plumbers will install the right valve, set proper levels, and confirm every part works together—your constantly running toilet fix done right.

After each adjustment, do a test cycle: flush, watch the flapper close, confirm the float stops the water at the right level, and listen for any continued trickling. If the tank holds steady and the bowl surface stays still, you’ve solved the problem.

When to Call B. Carlson

While many constant toilet running problems are quick wins, some symptoms point to wear or component issues that deserve professional attention. Calling B. Carlson means prompt diagnosis, certified expertise, and a repair that lasts.

• DIY didn’t solve it: If you’ve adjusted the chain, cleaned or replaced the flapper, set the float correctly, and repositioned the refill tube but the toilet constantly running continues, the issue may involve the fill valve, flush valve seat, or internal wear.
• Fill valve won’t shut off: If water continues to flow even with proper float settings, the fill valve may need replacement. Professional installation helps prevent leaks and ensures correct water levels.
• Persistent trickle into the bowl: If a new flapper and clean seat still won’t seal, the flush valve seat may be damaged and require resurfacing or a new assembly.
• Intermittent refills without use: Random refills suggest a slow leak or intermittent valve failure. A precise diagnosis prevents repeat part swaps and wasted time.
• Aging toilet with multiple worn parts: Older fixtures often have several parts wearing out together—flapper, seat, and fill valve. A professional assessment can recommend the most reliable way to restore performance.
• Moisture at the base or behind the toilet: Any dampness around the base or water stains on adjacent walls suggests issues beyond tank mechanisms. Addressing these promptly protects floors and finishes.

Our plumbers handle these issues every day across Albuquerque, Rio Rancho, Bernalillo, Corrales, and Los Lunas. We’ll find the cause, explain options clearly, and complete the repair with care. You’ll get a toilet that shuts off reliably and a water bill that reflects what you actually use—no surprises.

Practical Tips to Prevent a Continuous Running Toilet

Once your toilet runs properly, a few simple habits help it stay that way:

• Use quality replacement parts: Cheaper flappers and seals wear out faster. Choosing decent components reduces the chance of recurring leaks and constant toilet running.
• Keep an eye on water levels: Occasionally lift the tank lid and make sure the water line stops about an inch below the top of the overflow tube.
• Check for silent leaks: A quick dye test can confirm a flapper leak. Add a few drops of food coloring to the tank, wait 20–30 minutes without flushing, and look for color in the bowl. If you see it, the flapper or seat is leaking.
• Protect against sediment: Our area’s water can carry minerals and fine sediment that affect valves over time. If you notice grit or scale in the tank, consider periodic inspections or ask about steps to reduce buildup inside fixtures.
• Act early: The sooner you address a toilet constantly running, the less water you waste and the less stress on internal parts.

Small checks like these can prevent a continuously running toilet from sneaking up on you. If something looks off, give us a call—our team will be there fast to help.

Repair vs. Replace: Finding the Right Path

Most running-toilet problems don’t mean you need a brand-new toilet. Replacing a flapper, correcting a float setting, or installing a fresh fill valve typically restores solid performance. Consider replacement if:

• Cracks or structural issues: Any crack in the tank or bowl calls for replacement.
• Repeated repairs: If you’ve replaced multiple parts in a short time and the problem returns, a comprehensive rebuild or new fixture may be more reliable.
• Performance concerns: Older models may flush poorly and use more water per flush than modern designs. Upgrading can improve efficiency.

Our plumbers will walk you through the pros and cons, share straightforward recommendations, and help you choose the route that fits your goals for efficiency, reliability, and care of your home.

Why Homeowners Choose B. Carlson for Constant Toilet Running Issues

When you’re dealing with a toilet constantly running, you want a dependable fix and clear guidance. B. Carlson Heating, Air Conditioning & Plumbing delivers both, with a neighborly approach and certified skill built over more than five decades in Albuquerque.

• Trusted since 1971: Deep roots in the community, proven plumbing expertise, and a reputation for reliable work.
• Certified, courteous technicians: Friendly pros who protect your home, explain what they’re doing, and test every repair.
• Fast response: Our team will be there quickly to diagnose, make repairs, and confirm the system shuts off properly.
• Quality parts and long-lasting fixes: We match components to your toilet and calibrate the fill valve, float, flapper, and refill tube to work together the right way.

We’re proud to be Your Best Friend in Home Services. Whether you want help with a constantly running toilet fix or a broader plumbing check, our goal is to save you time, water, and worry—so your home runs quietly and efficiently, day after day.

Clear, Safe Guidance You Can Trust

This guide was written to help you diagnose and solve constant toilet running safely. It focuses on simple, low-risk adjustments most homeowners can perform without special tools. We won’t ask you to handle gas lines or attempt complex internal rebuilds. If a repair requires shutting off supply lines, opening connections, or reseating assemblies that must be watertight, it’s safer and faster to call a licensed plumber.

Key takeaways:

• Most constant toilet running problems are simple and inexpensive to fix.
• A toilet constantly running can waste hundreds of gallons a day and raise your bill.
• Issues typically come from worn or misadjusted parts—not major plumbing failures.
• With a careful look inside the tank, you can often diagnose the issue safely and prevent a continuous running toilet.

Need a Hand with a Continuously Running Toilet?

If your toilet constantly running is giving you trouble, you don’t have to live with the noise — or the water waste. B. Carlson Heating, Air Conditioning & Plumbing is here to help across Albuquerque, Rio Rancho, Bernalillo, Corrales, and Los Lunas. Our team will be there fast, make a precise diagnosis, and deliver a constantly running toilet fix that lasts.

We’ll make sure the flapper seals, the fill valve shuts off, the float is set correctly, and the refill tube is positioned the right way—so your toilet runs right, flush after flush. That’s the neighborly, dependable service you can expect from Your Best Friend in Home Services.