Most water heater calls in San Antonio come down to one of three things: an ignition or element fault that is genuinely repairable, sediment that has quietly eaten years off the tank, or a tank that has rusted through and cannot be saved. Silverback Plumbing and Drain repairs, replaces and converts water heaters across the city, and will tell you honestly which of the three you have.
Treat these as urgent
- Water actively pooling around the base of the tank — shut the cold supply valve on top of the unit and call.
- A gas smell anywhere near the heater. Leave the building, call CPS Energy at (210) 353-4357 from outside, then call us.
- Scalding water at the tap, or temperature swinging wildly. That is a thermostat or mixing fault, not a quirk.
- A burning smell, or scorching on or near an electric unit.
What usually goes wrong
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No hot water at all
A failed heating element or thermostat on electric units; a pilot that will not hold or a failed thermocouple on gas. Most of these are parts, not a new heater.
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Hot water runs out fast
Either the tank is undersized for the household now, or sediment has taken up enough of the tank that the usable capacity has shrunk.
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Banging or popping while heating
Sediment on the tank floor trapping water that flashes to steam underneath it. This is the sound of a tank being cooked from the inside.
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The tank itself is leaking
Water from the body of the tank rather than a fitting means the steel has gone. There is no repair for that.
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Rust-coloured hot water
Usually a spent anode rod, which is the sacrificial part that is supposed to corrode instead of the tank. Replaced in time, it buys years.
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A tankless unit throwing a code
The code names the fault. We read it and diagnose the part behind it rather than swapping components until it stops.
Repair it, or replace it?
This is the first question almost everyone asks, usually standing next to the thing. There is no rule that fits every case, but this is the framework we actually use, and we will tell you when repair is the cheaper and smarter call.
| Your situation | What we would usually say |
|---|---|
| Under 8 years old, tank not leaking | Repair Elements, thermostats, thermocouples and valves are all parts. |
| 10 to 12 years or older | Replace Past the point where money spent on it returns much. |
| The tank body is leaking | Replace A rusted-through tank cannot be sealed, and it will not wait politely. |
| Two or more repairs this year | Replace The pattern rarely improves once it starts. |
| Bills climbing with no change in usage | Replace Usually sediment forcing the burner to work far harder than it should. |
| The household outgrew the tank | Replace Size up, or move to tankless if the gas and venting allow it. |
Tank or tankless, if you are replacing anyway
| Tank | Tankless | |
|---|---|---|
| Upfront cost | Lower | Higher, and higher again if gas or venting has to change |
| Hot water supply | Limited by tank size | Continuous, but limited by flow rate rather than volume |
| Running cost | Higher — it keeps a tank hot around the clock | Lower, because it only fires on demand |
| Space | A floor footprint in a garage or closet | Wall mounted, roughly the size of a carry-on |
| Expected life here | Shorter than rated without a softener | Longer, but scale still has to be flushed out annually |
| Best fit | Households wanting the cheaper install and a familiar system | Households that keep running out of hot water, or want the floor space back |
The U.S. Department of Energy publishes an independent comparison of water heating efficiency if you want a source that is not selling you anything.
What a replacement actually costs
We quote before work starts, and the number moves on four things rather than on a price list:
- Type and capacityA like-for-like tank swap is the low end. Moving to tankless, or up a size, is not, because the supporting work changes with it.
- Gas, electrical and ventingA tankless conversion often needs a larger gas line or a dedicated 240V circuit and different venting. That work is usually the difference between the two quotes you have been given.
- Where the unit livesGarage floor is straightforward. An attic platform, a tight closet, or anything reached up a ladder takes longer and needs a drain pan and safe pan line done properly.
- What code requires nowExpansion tanks, pan drains, seismic strapping and shutoff placement have all changed over the years. A 15-year-old install rarely meets what a new one has to.
Why tanks die young in San Antonio
San Antonio Water System reports local hardness at 15 to 20 grains per gallon, which the Water Quality Association classifies as very hard. The national average sits nearer 7 to 10.
Every gallon that enters your water heater carries roughly twice the mineral load of a typical American city, and when it is heated those minerals drop out as sediment on the tank floor. That layer insulates the burner from the water above it, so the steel has to run hotter to deliver the same shower. Hotter steel fails sooner. It is why a unit rated for twelve years commonly starts failing here at eight or nine, and why the popping noise is a symptom rather than a quirk.
Flushing annually holds it back. Removing the minerals before they ever reach the tank works better — which is what a whole-home water softener does, and why it is the single most effective thing a San Antonio homeowner can do for water heater life.
How to get more years out of the one you have
- Flush the tank once a year, before sediment hardens into a crust that will not drain.
- Check the anode rod every two to three years and replace it when it is spent. This is the part that decides whether the tank rusts.
- Set the thermostat to 120°F — hot enough for the house, easier on the steel, and less likely to scald.
- Test the temperature and pressure relief valve annually. A seized T&P valve is the one failure mode that turns a water heater dangerous.
If you would rather not track that, annual water heater service is part of our plumbing maintenance plan, along with the rest of the house.
What a tankless conversion involves
Switching from a tank to tankless is not a one-for-one swap, which is where DIY conversions and suspiciously cheap quotes both come unstuck. A tankless unit needs gas volume the old line may not carry, or a dedicated 240V circuit, plus venting rated for its output and a mounting position that meets clearance. We size the unit to your fixture count and peak demand first, then do the gas, water, electrical and venting as one job rather than leaving you to coordinate three trades.
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
What are the signs my water heater needs attention?
Inconsistent or no hot water, water around the base, rust-coloured hot water, a rotten-egg odour from the hot tap, and popping or banging while it heats. Any one of them is worth a look before it becomes a replacement.
How long should a water heater last in San Antonio?
Tanks are rated for 8 to 12 years and frequently fall at the lower end here because of sediment from very hard water. Tankless units run 20 years or more, provided they are descaled annually. A softener moves both numbers up considerably.
Is my banging water heater dangerous?
Not immediately, but it is telling you something. The noise is water flashing to steam under a layer of sediment on the tank floor, which means the burner is working through an insulating crust and the steel is running hotter than it was designed to. It shortens tank life and it is worth flushing.
How much does water heater replacement cost?
It depends on the type and size of unit, where it sits, and whether gas, electrical or venting work is needed to bring the install up to current code. We look at your specific setup and give you a firm price before any work begins.
Can a leaking water heater damage my home?
Yes, and quickly. A tank holds 40 to 80 gallons and keeps refilling as it empties. A slow leak warps flooring and feeds mould behind drywall long before anyone notices. If you see water around the tank, shut the cold supply valve on top of it and call the same day.
Is a rotten-egg smell from the hot tap dangerous?
From the hot water specifically, it is usually a reaction between the anode rod and bacteria in the tank — unpleasant, not hazardous, and fixable. A rotten-egg smell in the air rather than the water is a different matter entirely and should be treated as a gas leak.
Is tankless worth it here?
It is, if you keep running out of hot water or want the floor space, and if your gas supply and venting can support it without heavy modification. It is a harder case to make on a straight like-for-like budget replacement. We will tell you which side of that line your house falls on.
Do you install a water heater I have bought myself?
Yes. Send us the model before the visit so we can confirm the gas, electrical and venting requirements match what is already there.
Cold showers do not fix themselves.
Whether it is a thermocouple or a tank that has finished, we will tell you which before we quote it, and most repairs and replacements are done the same day.
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
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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)