Where the water is coming from tells you whether to repair or replace. Water at a fitting, the relief valve, or a connection on top is usually a repair. Water seeping from the bottom of the tank itself, or a tank that is wet all the way around, means the tank has failed, and no repair fixes a tank. Turn off the water supply to the heater, and turn off the power or set a gas heater to pilot or off while you work it out.
One safety point before anything else. If you have a gas water heater and smell rotten eggs in the air near it, that is gas. Leave the house, do not touch switches or use a phone inside, and call 911 or your gas utility from outside. Water problems can wait. A gas smell cannot.
This guide goes through the leak locations, how long a tank water heater usually lasts, why the pressure relief valve drips, what hard water does to a tank, and how to flush one so it lasts longer.
Read the Leak: Top, Side, or Bottom
Start by finding the wettest spot and tracing upward, since water runs down before it drips.
Leaking from the top is the most common search, and it is usually good news. The top of the heater holds the cold inlet and hot outlet connections, the relief valve, and sometimes an anode rod fitting. A loose or corroded nipple, a failed connector, or a weeping valve can all drip down the side and look like the tank is leaking. These are often repairable.
Leaking from the side is often the relief valve discharge pipe, the drain valve near the bottom, or a connection. Check each before assuming the worst.
Leaking from the bottom, or a puddle with no source you can see, is where you have to be honest. Water at the bottom may be the drain valve, which is a small repair. If the drain valve is dry and water is coming from under the tank or out of the jacket seams, the steel tank has rusted through from the inside. That is the end of that heater.
To check: dry everything with a towel, wrap dry paper around each fitting, and see which one gets wet first. Do not use the heater with the tank leaking, and shut the supply to limit damage.
Why the Pressure Relief Valve Leaks
The relief valve is a safety device. Its job is to open if pressure or temperature in the tank climbs too high, and it should never be plugged, capped, or tightened to stop a drip. A plugged valve on a heater that overheats is a real hazard.
A valve that drips can mean a few different things. The valve itself may be worn or has a bit of mineral grit on its seat. The water pressure to the house may be too high. Or the system is closed, meaning a check valve or pressure reducing valve stops expanding hot water from backing up into the supply, so the pressure in the tank spikes every time it heats.
That last case is common. Heated water takes up more room, and a closed system has nowhere to put it. A thermal expansion tank gives it somewhere to go. On a recent job in Fannett, a 1976 Rheem water heater was replaced with a new Rheem electric unit, and a thermal expansion tank went in with it for exactly this reason.
If the valve drips constantly or runs hot water, have it checked. Replacing a valve is simple. Finding out why it opened is the real work.
How Long a Water Heater Lasts
A tank water heater is a wear item. There is no exact expiration date, and the honest answer is that life depends on the water, the maintenance, and the heater. A tank that has been flushed and has a healthy anode rod can outlast one that never was. Once a heater is well into its second decade, you are on borrowed time, and a leak from that age is more likely a retirement than a repair.
The clues beyond age: rust colored water from the hot tap, popping or rumbling noises, water that runs out faster than it used to, and a rusty stain or moisture at the base. The data plate on the side of the tank carries a serial number that encodes the manufacture date. Manufacturers explain how to read it on their sites.
An old heater with a small, fixable leak is a judgment call. If the repair is cheap and the tank is otherwise sound, repair makes sense. If you are fixing a fitting on a heater that is rusting and past its prime, you may be paying twice. We will tell you which side of that line yours is on, and estimates are free.
What Hard Water Does Around the Golden Triangle
Minerals in the water settle out when it is heated, and they collect as scale. In a tank heater that scale builds up on the bottom, where it insulates the water from the burner or lower element. The heater works harder, takes longer to recover, and runs hotter at the tank bottom. That stress shortens the tank's life and can rumble or pop as water boils under a layer of sediment.
Scale also clogs the drain valve, the relief valve seat, and the small passages in a tankless unit. Sediment is one reason a drain valve will not flow when you try to flush the tank.
How hard your water is depends on your supply. Public systems in the Golden Triangle are regulated by TCEQ for safety, but hardness is mostly a nuisance and not a health issue, and it varies between systems and wells. White crust on faucets and fixtures is the quick tell. A water softener helps, and flushing the tank regularly helps even without one.
Across Jefferson County and Orange County, from the Neches to the Sabine, hard municipal water is the norm, and Gulf Coast heat in an attic closet makes a stressed tank work harder still.
How to Flush a Tank Water Heater
Flushing clears sediment out of the bottom of the tank. It is a basic maintenance job, but it comes with real risks, and if anything about it feels wrong, stop.
First turn off the power at the breaker for an electric heater, or set a gas heater to pilot or off. Close the cold water supply valve to the heater. Open a hot tap somewhere in the house so the tank can drain without a vacuum. Connect a garden hose to the drain valve near the bottom and run it to a drain or the yard. Hot water can scald, so let the tank cool first. Open the valve and let it run.
When the water comes out clear, close the drain valve, remove the hose, open the cold supply, and leave the hot tap open until water runs steady, then close it. Only then restore power to an electric heater. Turning an electric element on before the tank is full will burn it out.
If the drain valve clogs with sediment, or drips after closing, or the tank has not been flushed in many years, call. A stuck valve forced open can break, and sediment that has been sitting for a long time can be packed hard.
Repair or Replace: A Plain Way to Decide
Repair makes sense when the leak is at a fitting, valve, or connector, the tank is dry, and the heater is not near the end of its life. Replace when the tank itself is leaking, when the heater is old and showing rust or sediment trouble, or when a repair would cost a large share of a new unit.
If you replace, you have choices. A like for like tank is the simplest. A larger or more efficient tank may suit a bigger household. A tankless unit is a different install with different needs, which we cover in a separate guide. Gas versus electric depends on what the house already has and what it can support.
Storm history matters too. Heaters that sat in Harvey or Imelda floodwater need their controls inspected or replaced, and freezes like Uri can crack fittings that start leaking later. If your heater lives in an attic or an open garage, ask about insulation and protection.
N-Sink is open 24 hours, every day, and a water heater that fails at night is still a problem to solve that night.
