Water heater leaking in Boise and the Treasure Valley: what to do in the next 15 minutes
Shut it down: step by step
- Turn off the energy. Electric: switch off the water heater's breaker (often a double breaker labelled "WH" or "water heater"). Gas: turn the control knob on the gas valve to "OFF" or "PILOT", and close the gas supply valve on the pipe feeding the heater (handle across the pipe = closed).
- Close the cold-water supply to the heater. It is the pipe into the top of the tank, usually marked "cold", with a valve above the tank. Turn a round handle clockwise; turn a lever a quarter-turn.
- Can't find or close it? Close your home's main water valve instead (garage, utility room or crawl space where the line enters the house).
- Contain the water. Towels, a wet-vac, and a bucket under any drip. If the tank sits in a drain pan, check whether the pan's drain line is clear.
- Photograph the heater, its label and the water before cleanup. The label shows the model, serial number and often the manufacture date, which you will need for a warranty or insurance claim.
- Optional, only if the tank itself is leaking: drain it to stop the leak. Attach a garden hose to the drain valve at the bottom, run it to a floor drain or outside, open a hot-water faucet in the house to let air in, then open the drain valve. Let the water cool first, it can be hot enough to burn.
Our 24/7 local pro line for Boise and the Treasure Valley is opening soon. Until then: stop the water using the steps on this page, then contact a licensed water damage restoration company in your area. Check that they are licensed and insured before work begins.
Where is it leaking from? What it usually means
| Where you see water | Likely cause | Usual fix |
|---|---|---|
| Pipes or fittings on top | Loose connection, worn flex connector, corroded nipple | Tighten or replace the connector (repair) |
| Pipe running down the side (relief valve discharge) | Temperature-pressure relief valve opening: too much pressure or heat, or a failing valve | Have a plumber test it; may need a new valve or an expansion tank |
| Drain valve at the bottom | Valve not fully closed or worn washer | Close it, cap it, or replace the valve (repair) |
| Pooling under the tank, no visible source | Tank corroded through from the inside | Replace the heater |
| Water only on the outside after a hot shower | Condensation, common on gas units in cold weather | Often normal; watch it for a day |
The relief valve is a safety device. Never cap it or plug its discharge pipe.
Repair or replace?
- Age: the U.S. Department of Energy puts the typical life of a tank (storage) water heater at about 10 to 15 years. The year of manufacture is often coded in the serial number on the label.
- Tank leak: a leak through the tank wall cannot be patched. Replace.
- Fitting, valve or connector leak: usually repairable for much less than a new heater.
- Permits: replacing a water heater in Idaho is plumbing work. Ask your plumber whether a permit is needed for your city and whether it is included in the quote.
Water damage from the heater: why speed matters
A standard tank holds roughly 40 to 50 gallons. Water heaters often sit in garages, closets and utility rooms next to finished walls and carpet. Wet drywall, carpet pad and cabinet bases should be dried or removed quickly: the U.S. EPA advises drying wet building materials within 24 to 48 hours to help prevent mold. A leak that ran unnoticed behind a closet door for days is the expensive version. See what water damage restoration costs.
Insurance in plain terms
Most homeowners policies will not pay for a new water heater that simply wore out. Many do cover sudden and accidental water damage the heater caused, such as wet floors and walls. Damage from a slow leak that went on for weeks is commonly excluded. Photograph everything and call your insurer or agent before you throw anything away.
Prevent the next one
- Put the heater in a drain pan piped to a drain, and add an inexpensive leak sensor on the floor.
- Ask a plumber to check the anode rod every few years and flush sediment; the Department of Energy recommends periodic anode inspection.
- Note the install date on the tank with a marker. Plan replacement before it reaches the end of its life.
Quick answers
Is a leaking water heater an emergency?
A leak from the tank itself usually means the tank has corroded through and will not get better; it can fail suddenly and release the whole tank. Shut off the water and power or gas and arrange replacement. A drip from a fitting or the relief valve can often be repaired.
Can I still use hot water if the tank is leaking?
No. Once the cold supply is closed and the heater is off, do not reopen them until a plumber has checked it. A heater left on with too little water can be damaged.
How long do tank water heaters last?
The U.S. Department of Energy says storage water heaters typically last about 10 to 15 years. If yours is in that range and the tank is leaking, replacement is the usual answer.
Will insurance pay for a leaking water heater?
Policies usually do not pay to replace a heater that wore out, but often cover sudden water damage it caused to floors and walls. Slow leaks that went on for weeks are commonly excluded. Check your policy.
Related
- Burst or frozen pipe: the first 60 minutes
- Water damage restoration cost in Boise (2026)
- Mold after water damage: the 24–48 hour window