Water Heater Leaking? Follow This Order of Operations

Treat this like a flowchart: do the steps in order, and by the end you'll know whether you're dealing with a cheap fix or a unit that's done.

Step 1: Stop the damage first

1. Close the cold-water inlet valve above the heater if it's safe to reach; use the home's main shutoff if it's stuck.
2. Cut power at the breaker for electric units, or turn the gas control to OFF — don't service a burner on a leaking unit.
3. Move anything nearby that water would damage; on a finished floor or a garage with stored items, water spreads fast.
4. Leave standing water alone for now unless the leak is severe — the water level can help pinpoint the source.

Smell gas? Leave the building and call the utility or 911 from outside. Active, spreading leak? Request emergency water heater service right away.

Step 2: Trace where the water is actually coming from

Dry every surface, lay down paper towel, and watch where wetness reappears — water runs down the tank, so a puddle at the base can start well above it.

Source	Verdict
Temperature-and-pressure relief valve dripping from its discharge pipe	Usually repairable — but check for a failed expansion tank or high static pressure causing it
Drain valve weeping at the bottom spigot	Repairable — tighten, cap or replace the valve
Inlet/outlet connections, unions or flex lines at the top	Repairable — corrosion or a loose fitting
Element gasket seeping (electric units)	Repairable — replace element and gasket
Condensate line on a tankless or high-efficiency unit	Often normal drainage; check for a clog if it's pooling
Water seeping from the tank shell itself, jacket wet, steady puddle with dry fittings above	Not repairable — internal corrosion has breached the tank; this means replacement

Step 3: Understand why tanks corrode through here

Three local factors compound over a tank's life: moderately hard NTMWD-supplied water (roughly 7–11 grains per gallon) builds sediment that traps heat against the tank floor; the anode rod eventually gets consumed, after which the steel itself starts corroding; and thermal-expansion pressure spikes on a closed plumbing system stress the shell and relief valve daily. Add a hot attic or garage and a decade of cycling, and a year-11 failure is entirely predictable — which is also why annual flushing and anode checks genuinely extend service life.

Step 4: Decide — repair or replace?

Repair looks right when: the leak traces to a valve, fitting, connector or gasket; the unit is under roughly 8 years old; the tank shell itself is dry and sound; and this is the first issue the unit has had.

Replacement looks right when: water is coming through the tank body itself; the unit is past 10 years and needs a significant part; hot water runs rusty or the tank rumbles heavily; this is a second or third service call in a short span; or the unit was undersized for the household to begin with (see our sizing guide).

Step 5: If it's replacement, what should be included

Correct sizing for your household, a new relief valve with compliant discharge routing, an accessible shutoff, new flexible connectors, a drain pan piped to an approved location, verified expansion control, correct venting or a verified circuit, and haul-away of the old unit. Permits and inspection run through the City of Plano, or the relevant city or county elsewhere in Collin, Denton or Dallas counties.

Next step

Photograph where the water appears and the unit's rating plate, then send both through our free quote form for a straight recommendation — leak repair, a component repair, or replacement.

More From the Blog

• Water Heater Replacement Cost: A Plano Buyer's Checklist
• Repair or Replace? A Plano Homeowner's Decision Guide
• Tank vs. Tankless in Plano: Side-by-Side Comparison
• Water Heater Sizing: A Plano Q&A
• How Long Will My Water Heater Last? A Plano Timeline
• Gas or Electric? Answering It for Your Plano Home