Water Dripping on the Water Heater Pilot Light
On this page (7 sections)
The Short Answer: Water dripping onto the pilot of a gas tank heater is condensation from the cold tank and flue, a leak above (relief valve, pipe fittings, anode) running down into the burner area, or the tank itself leaking. Condensation is common and usually stops once the tank is warm; the other two need repair. Turn the gas control to OFF while you look.
Condensation or a leak?
When a gas burner heats a tank full of cold water, water vapor in the exhaust condenses on the cool tank bottom and flue and drips onto the burner and pilot. You may hear sizzling. A. O. Smith’s technical bulletin on condensation (opens in a new tab) explains how this can be mistaken for a tank leak.
| Pattern | Likely source |
|---|---|
| Drips mainly after a lot of hot water is used, in cold weather, or on a new heater; stops after the tank warms up | Condensation |
| Drips continue even when the tank is hot and the burner is off | A leak, not condensation |
| Wet relief-valve pipe, wet fittings on top, or water trails down the jacket | Leak from above running into the burner area |
| Water or rust in the burner area with fittings dry | Possible tank leak; needs inspection |
Why the pilot goes out
Water hitting the pilot can put out the flame or cool the thermocouple (or thermopile) so it no longer holds the gas valve open. The pilot then goes out repeatedly, and a new thermocouple will not help until the water stops. Persistent moisture also rusts the burner, pilot assembly, and flame arrestor screen on newer heaters. If your pilot keeps going out and the area is dry, see why a gas water heater won’t stay lit.
What you can check safely
- Turn the gas control to OFF.
- Dry the relief-valve discharge pipe, the hot and cold pipe connections on top of the tank, and the jacket with paper towels.
- Check the floor and drain pan.
- After a few minutes, see which area is wet again.
Also note whether the dripping happened right after heavy hot-water use or on a cold morning. That timing points toward condensation.
Do not remove the burner access door or the inner door on a sealed combustion chamber, and do not try to dry the pilot by hand. If you smell gas, leave and call the gas utility from outside.
Sources from above
- Relief valve: a valve that weeps or discharges can send water down the outside of the tank. High house pressure or a failed expansion tank is a common cause. See overflow keeps discharging.
- Pipe connections on top: a leaking union, flexible connector or push-fit fitting can drip down to the burner opening. See water coming from the top of the water heater.
- Vent and draft hood: condensation in a cold vent can run back down onto the heater; see vent pipe leaking.
What the technician will check
They will confirm whether the water is condensation or a leak by watching the heater through a heating cycle, trace any leak from above, and inspect the burner, pilot assembly, and combustion chamber for rust and water damage. They may clean or replace the pilot assembly and thermocouple after the water problem is solved. If the water is coming from the tank itself, the tank has failed. If the burner area is wet with standing water, see gas water heater dripping on burner.
Repair or replace
Condensation is not a defect and usually needs no repair beyond keeping the temperature setting reasonable and the vent working. A leaking fitting or relief valve is a repair. A leaking tank always means replacing the heater.
Frequently Asked Questions
Q: My new water heater drips on the burner. Is it defective? A: Not necessarily. A new tank full of cold water produces the most condensation. If dripping stops once the tank reaches temperature, it is normal. If it continues with a hot tank, have it checked.
Q: Can I keep using the heater while I figure it out? A: If the dripping is clearly condensation and the pilot stays lit, yes. If water keeps coming with the tank hot, or you see rust or standing water in the burner area, leave the gas control off until it is inspected.
Manuals and supporting references
These links distinguish general safety information from model-specific documentation. A manual directory helps you locate your unit’s instructions; it does not establish that every model uses the same parts, codes, or test values.
- A. O. Smith technical bulletin 15: condensation (opens in a new tab)Why combustion condensate can resemble a tank leak; not a diagnosis of another manufacturer’s model.
- A. O. Smith technical bulletin 51: puddles around a heater (opens in a new tab)Common water-leak sources and the distinction between fittings and a failed tank.
- PG&E: recognizing and responding to a gas leak (opens in a new tab)Emergency actions for suspected fuel-gas leaks.
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