Water in the Drain Pan? 4 Causes, and Only One of Them Is the Tank
The drain pan under a water heater exists for one reason: to catch water before it reaches the ceiling, the subfloor or the carpet. Water in the water heater pan tells you something is getting out, but not always from the tank.
Dry the pan, then watch which of these four shows itself.
1. The relief valve has opened
The relief valve's discharge pipe often ends in or over the pan. A little water after a heating cycle, or a steady drip from the pipe, means the valve is opening or worn. The five reasons a relief valve drips explain which.
2. Condensation from the burner
Gas water heaters sweat when cold water fills them, and the drops fall into the burner area and the pan. It shows most on new tanks and after heavy use, and it stops as the tank warms. A thin film that comes and goes is usually this.
3. Another appliance draining into the pan
In attics, closets and utility rooms, an air conditioner or furnace condensate line is sometimes routed into the water heater pan. Trace every pipe that ends near the pan before you blame the heater.
4. The tank is leaking
If the pan keeps filling with the relief pipe dry, no condensate line nearby and the tank hot, the tank is the source. Moisture you can feel under the lower access cover confirms it. A leaking tank is replaced; see the six places to check on a bottom leak first, to be sure.
When the pan will not drain
A pan with a drain line should empty on its own. If water sits in it, the line is blocked or was never connected, and the pan can overflow. Clearing the line is simple; a pan with no drain at all is worth fixing, especially above a finished ceiling.
Is it normal to have water in the drip pan?
A few drops of condensation can be normal on a gas heater. Standing water, or a pan that refills, is not. Most of the causes above are repaired for an estimated $150 to $600. For a visit that traces it, see water heater leak repair near you.
Quick answers
Why is my water heater leaking into the pan?
It could be the relief valve opening, condensation, an AC line draining into the pan, or the tank itself. Rule out the first three before assuming the tank has failed.
Is it normal to have water in the drip pan of a water heater?
A few drops of condensation can be. Standing water or a pan that keeps refilling is not.
What should I do if there is water in the pan under the water heater?
Dry it, check the relief pipe and any condensate lines, and watch. If it refills with those dry, turn the heater off and have the tank checked.
Leak still running?
A plumber who handles leaking water heaters can trace it and quote it in writing.
