Your Water Heater Is Leaking: What To Do and What It Will Cost You
Published by Water Damage Restoration Specialists of San Antonio · Last updated 2026-07-25
A water heater holds forty to eighty gallons and is connected to a supply line
that will keep refilling it. When the tank fails, it does not stop at eighty gallons — it
keeps going until somebody closes a valve. In an attic, that is the single most damaging routine
failure a San Antonio home experiences.
Stop it now
- Close the cold water supply valveAbove the heater, on the incoming pipe. Turn
clockwise. If it is seized, close the main instead.
- Kill the energy sourceElectric: switch off the dedicated breaker. Gas: turn the gas
control valve to "off". Do not attempt to drain a heater that still has power to its elements.
- Do not touch the water if it is hotTank contents can be scalding. Let it cool.
- Photograph everythingBefore moving anything.
- Call a plumber and a restoration contractorThe plumber replaces the unit. We deal with
the structure.
Why attic installations are so much worse
A garage failure runs across a concrete floor and out. An attic failure puts water through
ceilings, down wall cavities, into insulation, across an entire upper floor and often into the
story below. In a two-story Stone Oak or Alamo Ranch home, a single attic tank failure routinely
affects both floors and most of the rooms in the house.
Most attic heaters sit in a drain pan — but a very large number of those pans are not
actually plumbed to a drain, or the drain line is blocked. Worth checking yours before you need
it.
Warning signs before failure
- Rusty or discolored hot water
- Rumbling, popping or banging during heating — sediment build-up
- Moisture, rust or corrosion around the tank base
- Water pooling in the drain pan
- Reduced hot water capacity, or water not getting as hot
- Age past ten years
The San Antonio hard water problem
San Antonio's water is hard, and hard water means mineral scale. Scale accumulates in the tank
bottom, insulates the heating element from the water, forces the unit to work harder and
accelerates corrosion of the tank lining. It is why heaters here often reach the shorter end of
the eight-to-twelve-year range rather than the longer end.
Flushing the tank annually genuinely extends its life. So does checking the anode rod, which
is a sacrificial component specifically designed to corrode instead of your tank — and which
almost nobody replaces, because almost nobody knows it exists.
Prevention worth doing
- Replace on your schedule, not its own — past ten years, particularly in an attic,
planned replacement is far cheaper than emergency replacement plus restoration
- Flush the tank annually to clear sediment
- Check the drain pan is actually plumbed to a drain — many are not
- Fit a leak detection shut-off device — these close the supply automatically when
they sense water, and for attic units they are excellent value
- Shut the supply off when you travel — a failure while you are away for a week is
a different category of loss entirely
Related guides
Need help with this?
We provide water damage restoration,
mold remediation and
fire damage restoration across
all 58 San Antonio ZIP codes, 24 hours a day.
Call (844) 476-1017.
Ask to see credentials — from us or anyone else
Before any technician starts work on your property, you are entitled to ask them
who they are and what qualifications they hold, and to ask to see documentation.
That applies to us and to every other contractor who knocks on your door. Ask at
your own discretion, take your time, and do not feel awkward about it — a
crew that is happy to be asked is the kind you want in your house. If anyone
refuses or rushes you past the question, treat that as your answer.
