We repair toilets across Norwalk, Whittier, Downey, Bellflower, and La Mirada every week, so we know the older SoCal housing stock and the hard water that comes with it. Aged tank parts and scaled-up rim jets are behind most of the running, leaking, and weak-flush calls we get. This page walks through each failure mode, how we diagnose it, and when a repair beats a replacement, so you know what you're dealing with before we arrive.
How we diagnose a toilet before we quote
A toilet repair starts with a two-minute diagnosis, not a sales pitch. We flush and listen for a tank refilling on its own, check the water level against the overflow tube, dye-test the tank to catch water leaking past the flapper, and rock the bowl to feel for a loose flange or a failed seal. Nine times out of ten the fault is one of four wearable parts: the fill valve, the flapper, the tank-to-bowl gasket, or the wax seal under the base. We stock the common fill valves, flappers, gaskets, and wax and urethane seals on the truck, so most single-toilet repairs are a one-visit fix. We tell you which part it is and quote by scope, not by the hour, before any work starts. Not sure whether it's a tank part or a drain problem? Call 213-254-8695 and we will tell you which one you are actually dealing with.
Running toilets and phantom flushes
A toilet that refills on its own every 10 to 20 minutes with nobody using it is leaking water from the tank into the bowl. This is what people call a phantom flush, and it quietly wastes hundreds of gallons a day and runs up your water bill. The cause is almost always a warped or scaled flapper that no longer seats, a flush-valve seal that has hardened, a fill valve that will not fully shut off so the tank drains down the overflow tube, or a float set too high. To confirm which, we put a few drops of food coloring in the tank and wait fifteen minutes without flushing; color in the bowl means the flapper or flush-valve seal is leaking. On a running toilet we replace the fill valve, flapper, and tank-to-bowl gasket as a set, because it costs barely more than the parts alone and kills the second service call when the next worn part goes. Swapping only the flapper when the fill valve is also aged out is the reason a running toilet comes back a couple of months later.
Repair a toilet fill valve
The fill valve is the tall tower on the left side of the tank that refills the bowl after each flush. When it starts sticking, humming nonstop, filling slowly, or refusing to shut off so water runs down the overflow tube, the internal seals are worn out and it is time for a new one. In almost every case we replace the fill valve rather than rebuild it, because fill valves are inexpensive and a rebuild on a worn body will not hold, especially on the hard water across our service area that leaves mineral scale inside the valve. We swap in a modern anti-siphon fill valve, set the water level correctly against the overflow tube so the flush has full volume without overflowing, and while the tank is open we check the flapper and tank-to-bowl gasket so the whole tank is fresh in one visit.
Toilet flapper repair
The flapper is the rubber seal at the bottom of the tank that lifts when you flush and drops back to hold water. It is the single most common toilet part to fail, because it sits in water constantly and warps, hardens, or scales up until it no longer seals. A flapper that will not seat lets water trickle from tank to bowl, which triggers the fill valve to keep topping the tank off, and that is what you hear as a running or phantom-flushing toilet. A flapper is a cheap part on its own, but replacing only the flapper when the fill valve or tank-to-bowl gasket is also worn is why a repair fails again within a few months. When we replace a flapper we match it to the flush valve so it seats cleanly, verify the chain length so it is not held open or pulled short, and check the parts around it so the tank works as a unit rather than sending you back to the store for one part at a time.
Toilet leaking at the base: wax ring and flange repair
Water pooling around the base of the bowl means the seal between the toilet and the drain has failed, or the closet flange under it has. This is the repair you do not want to leave alone, because water under the toilet rots the subfloor and lets sewer gas into the room. It happens most often on older bathrooms where new tile or vinyl was laid over the original slab, which leaves the flange sitting below the finished floor so the toilet rests on the tile instead of compressing the wax ring; the seal leaks and the bowl starts to rock. Our fix is the honest version. We pull the toilet, inspect the flange, and repair it or add a spacer or repair ring to bring it back to finished-floor height, then re-seat with a urethane wax-free seal that tolerates a rocking history better than plain wax, re-bolt with stainless closet bolts, and shim and caulk so the bowl sits solid. We do not re-caulk over a leak to hide it, which is the shortcut that lets a subfloor keep rotting under a good-looking bathroom.
Toilet installation and the wax ring seal
Whether you are installing a brand-new toilet or re-seating an existing one, the wax ring is the seal that makes or breaks the job. It sits between the bottom of the toilet and the closet flange on the drain, and when it is compressed correctly it blocks both water and sewer gas. Get it wrong and you have a slow leak at the base within weeks. The most common install mistakes we correct on other people's work are a flange set too low so the wax never fully compresses, a doubled-up wax ring stacked to reach a low flange instead of a proper spacer, and a toilet that was set, lifted to check alignment, then set again, which smears the wax and ruins the seal. On our installs we confirm the flange is at finished-floor height first, use a single correctly sized wax or urethane seal, set the bowl once and straight onto the bolts, and tighten evenly so the porcelain does not crack. If you are putting in a new fixture rather than repairing an old one, that is a fixture install; see our new toilet installation service linked below.
Weak flush and recurring clogs
A bowl that needs two flushes usually is not clogged. On the hard water across our service area, the most common cause is mineral scale plugging the small rim jets under the bowl rim and the siphon-jet hole at the bottom, which starves the flush of the water it needs to pull waste through the trap. When we get a weak-flush call we work through it in order: first we check the tank water level against the overflow tube, because set too low the flush has no volume and it is a thirty-second fix; then we inspect and descale the rim jets and siphon-jet hole where hard-water scale hides; then we verify the flush-valve seal and flapper timing so the tank actually dumps its water instead of dribbling. Only after that do we auger or camera the drain, because a real clog downstream is a different and larger job than a scaled bowl. If the clog truly is downstream we will say so and quote the drain work honestly rather than descaling a bowl that was never the problem.
A rocking toilet is not cosmetic
A toilet that rocks or shifts when you sit is not just annoying, it is a leak in progress. Every rock flexes the wax seal at the base until it breaks, and once that seal fails water and sewer gas escape under the floor and the subfloor starts to rot. Sometimes the fix is simply shimming and re-tightening the closet bolts, but if the bowl has been rocking for a while the wax is usually already compromised and the flange may be sitting too low. We pull the toilet, check the flange height and the bolts, correct whatever is letting the bowl move, and re-set it on a fresh seal so it sits solid. If you have a toilet that rocks, treat it as a same-day repair rather than waiting for the base leak to show up on your floor.
Toilet repair versus replacement: how to decide
Here is the version most companies will not put in writing. Do not let anyone sell you a new toilet when a rebuild kit and about forty-five minutes of labor fixes a running or weak-flushing one. If the porcelain is intact and the toilet is post-1994 (1.6 gallons per flush or lower), the wearable parts are the whole problem and a rebuild gives you another decade of service. Replacement genuinely is the better spend in three cases: the porcelain is cracked or crazed, because a cracked tank or bowl cannot be sealed reliably and will fail again; it is a pre-1994 high-volume toilet, where a modern low-flow model pays for itself on water savings; or the bowl has been rebuilt more than once and still leaks, which usually points to the flange or drain rather than the toilet itself. Where the toilet is sound and just needs parts, that is a repair and we will tell you to keep it. Where it truly needs replacing, that is a fixture install and we will say that too. Either way you get the honest answer before you spend a dollar.
Got questions?
Frequently asked questions
How do I fix a toilet that keeps running?
A running toilet is water leaking from the tank into the bowl, and it is almost always the flapper, the flush-valve seal, or a fill valve that will not shut off. To confirm the flapper, put a few drops of food coloring in the tank and wait fifteen minutes without flushing; if color appears in the bowl the seal is leaking. We replace the fill valve, flapper, and tank-to-bowl gasket as a set so the tank works as a unit, because fixing only one worn part is why running toilets come back a couple of months later.
Can you repair a toilet fill valve, or does it need replacing?
In almost every case we replace the fill valve rather than repair it. Fill valves are inexpensive, and by the time one is sticking, humming, or failing to shut off, the internal seals are worn and a rebuild will not last, especially on the hard water across our service area that leaves scale inside the valve. We swap in a modern anti-siphon fill valve, set the water level correctly against the overflow tube, and while the tank is open we check the flapper and tank-to-bowl gasket so the whole tank is fresh in one visit.
How do I know if my toilet needs a new flapper?
The classic sign is a toilet that refills on its own every ten to twenty minutes with no one using it, called a phantom flush. To confirm, put a few drops of food coloring in the tank and wait fifteen minutes without flushing; if color shows up in the bowl, the flapper or flush-valve seal is leaking and needs replacing. A flapper is a cheap part, but if the fill valve is also aged out we replace both, because fixing only the flapper is why running toilets come back.
How often does a toilet wax ring need to be replaced?
A wax ring can last the life of the toilet if the toilet never moves, but any time the bowl is pulled, re-set, or has been rocking, the wax should be replaced rather than reused. Water pooling at the base or a bowl that shifts when you sit means the seal has failed and needs replacing right away, because a leaking base rots the subfloor and lets sewer gas into the room. When we re-seat a toilet we use a fresh wax or urethane seal every time.
Is it worth repairing an old toilet or should I replace it?
If the porcelain is intact and the toilet is post-1994 (1.6 gallons per flush or lower), a rebuild kit gives you another decade and is the better value. Replacement is the smarter spend when the porcelain is cracked or crazed, when it is a pre-1994 high-volume model where a low-flow toilet pays for itself on water savings, or when the bowl has been rebuilt more than once and still leaks. We tell you which situation you are in before you commit either way.
My toilet rocks. Is that dangerous?
Yes. A rocking toilet eventually breaks the wax seal and leaks water and sewer gas under the floor, rotting the subfloor. It is usually a same-day fix: we pull the toilet, check the flange height and bolts, correct whatever is letting the bowl move, and re-set it on a fresh seal so it sits solid.
Are you licensed, bonded and insured?
Yes. Nava's Elite Plumbing carries a current California master plumber registration, $1M general liability coverage, and workers' comp on every technician. A certificate of insurance naming you or your property manager is available on request before we start.
Do you give upfront pricing?
Every job is quoted in writing before any work begins. We price by scope, not by the hour, so the number you approve is the number you pay — barring scope changes you approve in writing.
Do you require money down?
No deposit on standard service calls. On larger projects (repipes, sewer replacements, gas line installs) we phase work into progress payments tied to city inspection milestones — you never pay ahead of completed work.