Quick answer
A tank water heater's shut-off valve is on the cold water inlet pipe, usually at the top of the heater, marked or colored blue. A lever valve is closed when the handle is across the pipe; a round gate valve turns clockwise. Closing it stops new water entering, but the tank stays full and hot. Also turn the gas control to Off or Pilot, or switch off the breaker for an electric heater. If the valve will not turn or leaks around the stem, close the main water valve and call. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
Knowing where the water heater's shut-off is, before there is a leak, saves a lot of water and stress.
Where It Is
On a tank water heater, two pipes come out of the top: cold in and hot out. The shut-off valve is on the cold inlet, usually within a foot or two of the tank. It may be labeled "cold" or have a blue handle. Tankless heaters have valves on both lines, often in a service kit under the unit.
| Valve type | Closed when |
|---|---|
| Lever (ball valve) | Handle is across the pipe |
| Round handle (gate valve) | Turned fully clockwise |
How to Shut Off the Heater
- 1Close the cold inlet valve.
- 2Turn off the energy. Gas: turn the control knob to Off or Pilot. Electric: switch off its breaker. Running an empty tank damages electric elements.
- 3Catch the water from any leak with a bucket or towels.
- 4Do not open the drain valve unless you mean to drain it; the water can be scalding.
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
When the Valve Is the Problem
| Problem | What to do |
|---|---|
| Will not turn | Do not force; close the main water and call |
| Leaks around the stem | Snug the packing nut a quarter turn; replace if it continues |
| Turns but does not stop the flow | Worn gate valve; replace with a ball valve |
See shut-off valve leaking and emergency water shut-off.
What a Repair Costs
A valve replacement is a common, short plumbing job; see water heater repair for typical prices.
The Call
Call when the valve will not close or leaks, or the heater itself is leaking. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Where is the shut-off valve on a water heater?
On the cold water inlet pipe, usually at the top of the tank. It is often a lever or a round handle, sometimes marked blue.
Does closing the valve stop a water heater leak?
It stops new water going in, so a leak slows and stops once the tank is low or the pressure drops. The tank still holds hot water, so catch what comes out.
What if the water heater shut-off valve won't turn?
Do not force it, as old gate valves can break. Close the main water shut-off for the house and call a plumber to replace the valve.
Sources
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Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.
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