A water heater leaking from the bottom is stressful, but it is not always a disaster. Sometimes the cause is a loose valve that is easy to fix. Other times it means the tank is failing and needs to be replaced. This guide explains the most common causes of a water heater leaking from the bottom, what to do right away, and when to call a pro.
First: what to do right now
Before you look for the cause, make the area safe:
- Turn off the power. For an electric heater, switch off its breaker. For a gas heater, turn the gas control knob to OFF or PILOT.
- Shut off the cold water supply valve on the pipe at the top of the heater.
- Move rugs, boxes and valuables away from the water.
- If you smell gas, leave the home right away and call your gas company or 911 from outside.
6 causes of a water heater leaking from the bottom
1. A loose or faulty drain valve
Every tank has a drain valve near the bottom. If it is not fully closed, or its washer has worn out, water can drip from the valve and pool under the heater. A loose valve can often be tightened, and a worn valve can be replaced without replacing the whole heater.
2. The temperature and pressure relief valve
The temperature and pressure relief valve (T&P valve) releases water when pressure or temperature inside the tank gets too high. Its discharge pipe usually runs down the side of the heater, so the water appears at the bottom. Occasional drips can mean the valve is worn, but steady discharge can point to high pressure or overheating. This needs a professional check, because the valve is an important safety part.
3. Condensation
Gas water heaters sometimes produce condensation, especially when they are new or when very cold water enters the tank in winter. The drops fall onto the burner area and floor, which looks like a leak. If the water stops once the tank heats up, condensation is the likely cause.
4. Leaking pipe connections
Water can drip from the inlet and outlet connections at the top of the tank and run down the outside, collecting at the bottom. Check the top of the heater for wet fittings. Loose connections can often be tightened or resealed.
5. A leaking heating element gasket
Electric water heaters have heating elements behind access panels on the side. If the gasket around an element fails, water can seep out and run down to the floor. Replacing the gasket or element is a common repair.
6. A cracked or corroded tank
If water is coming from the tank itself, usually from the bottom seam, the inside of the tank has likely rusted through. Sediment from hard water speeds this up by trapping heat and moisture at the bottom. A leaking tank cannot be repaired, so replacement is the only safe option.
How to find the source of the leak
- Dry the floor and the outside of the heater completely.
- Check the top connections, the T&P valve and its pipe, the drain valve and the element panels.
- Wait and watch where new water appears first.
If you cannot see where the water starts, or it seems to come from under the tank, assume the tank is leaking and call a professional.
Repair or replace?
Leaks from valves, fittings and gaskets can usually be repaired. A leak from the tank body means it is time for a new water heater. Age matters too: if your heater is 10 years old or more, replacement is often the better long-term choice. You can compare prices in our water heater repair cost guide.
Water heater leaking in Greenwood, IN?
Greenwood’s hard water leaves extra sediment in water heaters, which can lead to leaks sooner than expected. If your water heater is leaking from the bottom, call now or request a free quote. A local pro can find the source, stop the leak and give you honest repair or replacement options.