A toilet is the fixture people put up with longest. It runs intermittently for a year, rocks slightly when you sit down, needs a second flush more often than it used to — and none of it feels urgent, so nobody calls. Two of those three are quietly costing money and one of them is a warning about the floor underneath. Silverback Plumbing and Drain repairs and replaces toilets across San Antonio, usually same day.
What is going on in there
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Runs constantly, or cycles on its own
Nearly always the flapper or the fill valve. Hard water stiffens the rubber until it stops sealing, the tank bleeds into the bowl, and the fill valve tops it up all night.
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Water at the base
A failed wax ring, sometimes a corroded or broken closet flange. By the time water reaches the visible floor it has been under the toilet for a while, which is why this one is not worth waiting on.
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It rocks when you sit down
Loose closet bolts, or a flange sitting below the finished floor. Every rock works the wax seal a little further open, which is how a wobble becomes a leak.
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Weak or incomplete flush
Mineral buildup in the rim jets and siphon passage, a flapper closing early, or a tank not filling to the right level. In water this hard, blocked jets lead the list.
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It clogs again and again
A toilet that blocks repeatedly is often not the problem. Recurring clogs across several fixtures point at the branch line or further down.
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The tank sweats
Condensation in a San Antonio summer dripping onto the floor and reading exactly like a leak. Worth ruling out before anyone pulls the toilet.
The dye test for a silent leak
A toilet leaking internally makes no sound and puts nothing on the floor, and it is the largest single water waster in most homes. This takes fifteen minutes and costs nothing.
- Take the tank lid off and set it somewhere safe and flat.
- Put a few drops of food colouring into the tank water. Do not flush.
- Wait fifteen minutes and do not use the toilet.
- Look in the bowl. Colour in the bowl means the flapper is leaking and the tank has been feeding the bowl continuously.
A flapper that fails this test can pass several hundred gallons a day without ever making a sound. If your bill rose and the yard is dry, test every toilet in the house before assuming the problem is outside.
Repair or replace
| Situation | Usually the right call |
|---|---|
| Running, weak flush, or a leak at the supply | Repair Flappers, fill valves and supply lines are inexpensive parts. |
| Leaking at the base, fixture otherwise sound | Repair New wax ring and bolts, flange inspected while the toilet is off. |
| Cracked tank or bowl | Replace Porcelain cracks spread, and a tank that fails does so all at once. |
| Anything predating 1994 | Replace Older units use up to 3.5 gallons a flush against 1.28 for a current high-efficiency model. |
| Third repair on the same toilet | Replace Parts availability and porcelain age are both working against you. |
| Flange broken or below floor level | Fix the flange regardless. A new toilet on a bad flange leaks exactly like the old one did. |
Why toilets wear out faster here
Water across the region tests between 15 and 20 grains per gallon, and inside a toilet that shows up in three places: scale narrowing the rim jets so the flush loses force, deposits stiffening the rubber flapper until it no longer seats, and buildup on fill valve components that makes them stick open or closed.
None of it is dramatic. It is simply why a toilet that flushed perfectly for six years gradually stops doing so, and why homes with a water softener go considerably longer between repairs.
What a replacement involves
A standard swap takes about two hours. We shut off and drain the old unit, remove it, then inspect the closet flange and subfloor while they are exposed — which is the part a rushed install skips — before setting the new toilet on a fresh wax ring, levelling and securing it, reconnecting the supply and testing for movement and leaks under normal use.
If the flange is corroded, cracked or sitting below the finished floor, it gets dealt with then. That is also the moment we find out whether a long-running base leak has reached the subfloor, and we would rather tell you before the new toilet is sitting on it.
What it costs
- Repair or replacementA flapper or fill valve is the low end and finishes in one visit. A full replacement includes removal, disposal and the new fixture.
- The fixture you chooseHeight, one-piece against two-piece, and flushing system account for most of the spread. Comfort height and a good 1.28 gallon flush are worth the difference.
- What is under the toiletIf the flange is broken or below floor level, correcting it is part of doing the job properly rather than an upsell. Subfloor damage from a long leak is priced once we can see it.
- How manyDoing several in one visit costs less per fixture than booking them separately.
When the toilet is the symptom
One toilet clogging occasionally is a toilet. A toilet that backs up when the washing machine drains, or gurgles when a nearby shower runs, is telling you about the line it shares — that belongs with drain cleaning, or with sewer line repair where roots or a collapsed section are involved. Sewage on a floor is an emergency rather than a scheduling matter, any hour.
Work is carried out by licensed plumbers under our Responsible Master Plumber, license RMP-43333, issued by the Texas State Board of Plumbing Examiners. You can verify that license yourself.
What San Antonio homeowners say
Reviews pulled live from our Google Business Profile, not retyped here.
Questions homeowners ask us
Why does my toilet keep running?
Almost always a worn flapper that no longer seals against the flush valve. Hard water stiffens the rubber until it stops seating, the tank bleeds into the bowl, and the fill valve keeps topping it up. It is an inexpensive part and a quick repair.
Is water around the base serious?
Usually yes. It generally means the wax ring has failed, and by the time water reaches the visible floor it has typically been seeping underneath for some time. Left alone it damages subfloor and, upstairs, the ceiling below.
How much water does a running toilet waste?
A badly seated flapper can pass several hundred gallons a day, silently. It is frequently the single largest water waster in a home, which is why a fifteen-minute dye test on every toilet is the right first move when a bill jumps.
Should I repair or replace?
Repair if the fixture is sound and the fault is a flapper, fill valve or wax ring. Replace if the porcelain is cracked, if it predates 1994 and uses 3.5 gallons a flush, or if you are on your third repair of the same unit.
Why does my toilet rock slightly?
Either the closet bolts are loose or the flange sits below the finished floor. Either way it needs correcting, because every movement works against the wax seal and a rocking toilet reliably becomes a leaking one.
Can I install a toilet myself?
You can, and plenty of people do it successfully. The two things that go wrong are a flange problem nobody noticed until the new toilet leaks, and a wax ring compressed unevenly while setting it. Both mean pulling the toilet again.
Why does it gurgle when the shower runs?
That is a venting or drain line issue rather than a toilet issue. Air is being pulled through the toilet trap because the line cannot breathe, usually from a partial blockage further down. Worth investigating before it becomes a backup.
Do you offer same-day toilet repair?
Yes, for most of the San Antonio area. We carry common flappers, fill valves and wax rings so the majority of repairs finish on the first visit.
If it is leaking at the base, sooner is better.
That water is going somewhere, and the somewhere is your subfloor. Most repairs are done in one visit with the parts already on the van.
Silverback Plumbing & Drain provides licensed plumbing and drain service for homes and businesses throughout the San Antonio area. From emergency repairs to routine maintenance, we diagnose the problem, explain the fix, and get it done right the first time.
Contact Info
Open Hours
- Open 24/7
Emergency service available nights, weekends, and holidays.
Copyright © 2026 Silverback Plumbing and Drain
Mark Vargas, Responsible Master Plumber #43333 Licensed through the Texas Board of Plumbing Examiners P.O. Box 4200, Austin, Texas 78765 (800-845-6584)