Toilet Repair & Installation
Cure a running, wobbling or leaking toilet, or set a new one in place.
Homeowner guide
Running Toilet Fix: A Lafayette, CO Homeowner Guide
A running toilet is one of the most common plumbing complaints, and one of the easiest to fix. The parts are inexpensive, and a repair usually takes less than an hour.
By the Lafayette Plumbers team ·
How a toilet works
Pressing the handle lifts a flapper at the bottom of the tank. Water rushes into the bowl and flushes it. The flapper falls back, the tank refills through a fill valve and a float shuts the water off at the right level.
When any of those parts fails, water keeps flowing. Knowing which part does what makes the diagnosis simple.
Test the flapper
Add a dye tablet or food coloring to the tank, then leave it unflushed for a quarter hour. Dye appearing in the bowl proves the flapper leaks. Hard water scale and age make the rubber stiff and warped.
Turn off the supply, flush, and replace the flapper with the same style. Match the size to the flush valve. A mismatched flapper will leak again.
Check the chain and the handle
A taut chain keeps the flapper from closing fully. One that is too loose can get caught under it. About half an inch of slack is right.
A handle that sticks can keep the flapper up. Clean the arm and make sure it returns freely.
Symptom, cause and fix
Match what you hear or see to the part.
| Symptom | Likely cause | Fix |
|---|---|---|
| Color in the bowl from dye | Worn flapper | Replace the flapper |
| Hissing after the flush | Fill valve not shutting off | Tune or swap the fill valve |
| Water keeps spilling down the overflow pipe | The float sits too high | Lower the float |
| Handle sticks | Dirty arm or tight chain | Clean it and add chain slack |
Adjust or replace the fill valve
If you hear hissing, or water runs into the overflow tube, the fill valve may be set too high or may be worn. Lower the float so the water stops one inch below the overflow pipe top.
A worn fill valve is cheap and quick to replace. Turn off the supply, drain the tank, unscrew the old valve and fit the new one. Hard water leaves grit that wears the seal over time.
Phantom flushes and other signs
A toilet that refills on its own now and then is leaking slowly from the tank into the bowl. That is the phantom flush. Fixing the flapper usually stops it.
A toilet that rocks, leaks at the base or runs only in certain seasons may have other causes. See toilet repair and installation for more.
When to call a plumber
When fresh parts do not end the running, the flush valve seat could be pitted, or the whole toilet may need replacing. A plumber can tell in minutes.
If you cannot shut off the supply or the shutoff valve is crusty, a plumber can replace it. See faucet and sink repair for stop valves.
Costs of ignoring the problem
A slow leak in a toilet can add dollars to the bill every month and it makes noise at night. Over a year the waste adds up, and a bill spike may be the first hint.
Cheap parts fix most cases. Waiting until the valve fails completely may lead to an overflow, so treat a running toilet as a small job that should be done soon.
Choosing replacement parts
Take the old flapper or fill valve to the store to match the size. Universal kits fit most tanks, but older models may need a specific brand.
Look for parts with clear installation steps and a warranty. Avoid dropping cleaning tablets in the tank, since they can damage rubber.
Water saving options
Dual flush kits and adjustable flush valves can lower water use without replacing the bowl. A low-flow model uses less per flush, though a good design still clears the bowl.
If you replace a toilet, check the rough-in distance, usually twelve inches from the wall, and the height you prefer.
Checking your work
After repairs, put several drops of dye in the tank and leave it unflushed for twenty minutes. Clear water in the bowl means the flapper seals.
Listen at night for the fill valve to kick on by itself. If it still does, the leak remains, and the seat or valve may need replacing.
Tools and time
Most flapper and fill valve swaps need only a towel, a bucket and perhaps pliers. Set aside half an hour for a first attempt.
If parts are corroded or the nuts will not turn, stop and call a plumber rather than risk cracking the porcelain.
Why a running toilet keeps happening
Rubber parts harden and warp over several years. Hard water speeds that up, since minerals coat the flapper seat and keep it from sealing. A chain that tangles, or a float set too high, causes the rest.
Knowing the cause matters because replacing only the flapper will not help if the seat is pitted or the float is misadjusted. Look at the whole refill cycle once, from flush to rest.
A step by step order of repair
Start with the cheapest part, the flapper, then adjust the chain, then the float, and only then replace the fill valve. Test after each change with dye, so you know which step worked.
If the toilet still runs after new parts, stop and call a plumber. The flush valve seat may need replacing, which is a bigger job.
When the toilet itself is the problem
A cracked tank, a leaking base and a wobbly bowl are not flapper issues. Water at the base often means the wax ring has failed, and the toilet has to be lifted and reset.
Older toilets also use more water per flush. Replacing one can cost less than repeated repairs and may lower the water bill.
Common questions
Answers on running toilet
A lot. A steady trickle can add thousands of gallons over a billing period.
No. Match the size and style to your flush valve.
The flapper may not seat, or the fill valve may be set too high.
Rubber flappers often last a few years, shorter in hard water.
Related services
Leak Detection
Locate a hidden leak inside a wall, under a floor or along a buried line before it stains drywall or inflates the bill.
Faucet & Sink Repair
End drips, weak flow, stuck shutoffs and dripping outdoor spigots.
More plumbing guides
Why the water bill jumped
A bill that suddenly climbs usually has a cause you can find. Check these likely suspects in order.
Tracking down a concealed leak
You can find many leaks with a meter, a dye tablet and a flashlight. Here is a step-by-step check.
Why the house smells like sewage
A rotten egg odor means sewer gas is getting in. Check the traps, the vents and the wax ring before you worry.
Speak with the phone desk
Toilet won't stop running?
Call the line if the water is overflowing or you cannot close the valve.
Call (720) 743-9476(720) 743-9476 · day and night