A water heater leaking from the bottom usually means the tank itself has failed, often from years of sediment buildup in hard water. Check first whether the water is coming from the drain valve, the temperature-pressure relief valve, or condensation on a cold tank. If the tank bottom is wet and rusty, the unit needs replacing, not repairing.
First: is it actually leaking?
Not every puddle under a water heater is a leak. Sort it out before you panic:
- Condensation. On cold mornings or with a cold tank, moisture beads on the outside and drips down. It dries up as the tank warms. If the puddle comes and goes with temperature, it's likely sweat, not a leak.
- T&P relief valve discharge. The temperature-pressure relief valve on the side has a discharge pipe running down. If that pipe is dripping, the valve is doing its job. But it's telling you pressure or temperature is too high, which needs attention.
- Drain valve seep. The small spigot near the bottom can weep if it wasn't closed tightly after a flush, or if its washer failed. Tighten gently; if it still drips, the valve needs replacing. A small job.
- The tank itself. Water beading or rust-streaking from the bottom seam, with no other source, means the steel tank has corroded through. Tanks don't get patched. They get replaced.
Why Citrus Heights water heaters fail from the bottom
Local water runs hard. Roughly 11 grains per gallon. Hard water drops sediment that settles on the tank bottom, and that sediment layer does two bad things: it insulates the bottom so the burner overheats the steel, and it traps moisture against the metal. Year after year, the bottom corrodes from the inside out. In 1970s-era homes where the original closet and venting are still in place, we see tanks give out right around the age you'd expect, and the failure almost always starts at the bottom seam.
What to do right now
- Active leak, water spreading: close the cold-water shutoff valve on top of the heater, then turn the heater off (breaker for electric, gas valve to pilot for gas). Put towels down and call (123) 456-7890.
- Slow seep, nothing spreading: put a pan or towels under it, snap a photo, and note whether it's getting worse. Don't ignore it. Tank leaks only grow.
- Don't drain the tank yourself unless you know the procedure; a corroded drain valve can snap off and turn a seep into a flood.
Repair or replace?
Simple rule: if the tank is leaking, replace the unit. Valves, thermostats, and fittings can be repaired; a rusted-through tank cannot, and no sealant fixes it for long. When we come out, we'll confirm the source first. Because replacing a water heater over what turned out to be a five-dollar drain valve washer would be an expensive mistake, and we don't make those on your dime.
Tank and tankless units fail in different places. A tankless water heater has no tank to split, so its leaks usually sit at fittings, valves, or the heat exchanger connections. A tank unit leaks from the tank body, the drain valve, or the top fittings. Knowing which type you have narrows the check before anyone touches a wrench.
Frequently asked questions
My water heater is leaking from the bottom. Can it be fixed?
Almost never. Water coming from the bottom seam means the steel tank has corroded through, usually from years of sediment in hard water. The fix is a new water heater, not a patch. What we can do is confirm the tank is truly the source before you spend money replacing it.
Is water under my water heater always a leak?
No. Condensation on a cold tank, a dripping T&P relief valve discharge pipe, or a weeping drain valve all put water on the floor without the tank itself failing. Dry everything, watch where fresh water appears first, and you'll usually find the real source.
Is a leaking water heater dangerous?
It can be. Water and electricity or gas don't mix, and a tank can fail suddenly once corrosion starts. If water is actively spreading, shut off the water supply to the heater, turn the heater off, and call a professional the same day.
How do I know if it's the T&P valve or the tank?
Follow the water. The T&P valve has a discharge pipe running down the side. If water is coming out of that pipe's end, it's the valve (or high pressure/temperature). If water is beading along the bottom seam of the tank itself, it's the tank.
Does hard water really kill water heaters faster?
Yes. Citrus Heights water runs about 11 grains per gallon, which is hard. Sediment settles on the tank bottom, overheats the steel, and accelerates corrosion. Flushing sediment yearly helps, but it can't reverse years of buildup.
Is a leaking water heater an emergency?
If water is spreading, the tank is leaking from the bottom, or you smell gas, treat it as urgent: turn the heater off, shut off water if you can do it safely, and call a professional the same day. A slow drip from a valve is less urgent, but it still needs checking before it gets worse.
Why is my water heater leaking from the bottom?
Leaking from the bottom usually means the tank itself has failed, often from rust or sediment damage inside the tank. A valve or fitting leak is different: it usually shows at the top or side. A tank leak usually means replacement, not a small repair.
Can a leaking water heater be repaired, or does it need to be replaced?
It depends where it leaks from. A leaking valve, drain or fitting can often be repaired. A leaking tank usually cannot be repaired reliably and needs to be replaced. The test is where the water is coming from, not how much water you see.
Can I still use my water while the water heater is leaking?
Cold water to other fixtures can usually still be used if the leak is small and contained, but do not use hot water from a leaking heater, and do not ignore a spreading leak. Turn the heater off and get it checked before you keep using hot water.
Why is my hot water rusty?
Rusty hot water often points to rust inside the water heater tank or in older steel pipes. If only hot water is rusty and cold water is clear, the heater is the first place to check. If both are rusty, the problem may be in the supply lines.
Related
- Hidden water leak detection
- Ceiling and wall leaks
- High water bill investigation
- Emergency leak repair
Think you have a leak?
Call AquaTrace Leak Detection to describe what you are seeing in Citrus Heights and get a plan to find it.
Call (123) 456-7890Last updated: October 25, 2026.