How to Drain a Water Heater With No Floor Drain
On this page (6 sections)
The Short Answer: You don’t need a floor drain. Turn the heater off, let the water cool, close the cold-water supply, open a hot faucet, then run a garden hose from the drain valve to anywhere lower: outdoors, a basement sink, a tub, or a toilet. If there is nowhere lower, use a small transfer pump or a wet/dry vacuum. Refill completely before turning the heater back on.
For the full drain-and-flush routine and how often manufacturers recommend it, see how to flush a water heater. This page covers where to send the water.
Before you start
- Turn the heater off. For gas, turn the control to OFF or the vacation setting as your manual describes. For electric, switch off the breaker. Electric elements must not be powered while the tank is empty.
- Let the water cool.
- Close the cold-water valve on the pipe into the top of the heater.
- Open a hot faucet somewhere in the house. This lets air into the tank so the water can flow out.
Pick a place for the water to go
Water flows out on its own only if the end of the hose is lower than the drain valve.
| Where the heater is | Practical option |
|---|---|
| Garage or utility room at ground level | Hose out the door to the driveway or yard, downhill |
| Basement | A sump pit or anything lower than the drain valve; otherwise a transfer pump to lift water to a laundry sink or outside |
| Closet on the main floor | Hose to a tub or toilet in a lower room, or to the outside through a door |
| Attic | Hose down to a tub or outdoors; watch for siphon and kinks |
| No lower point at all | Small transfer pump (drill-powered or electric), a wet/dry vacuum, or buckets |
A 40- to 50-gallon tank holds a lot of water. With buckets, plan on many trips and protect the floor.
Draining
- Connect a garden hose to the drain valve near the bottom of the tank and make sure the other end is secure in a sink, tub, toilet bowl, or outside.
- Open the drain valve slowly. Plastic drain valves on many tanks are fragile; turn gently.
- Check the hose end often. Don’t leave it unattended in a sink or toilet.
- If water stops before the tank is empty, sediment may be clogging the valve. Close the valve, then see water won’t drain from the water heater.
Refilling
- Close the drain valve and remove the hose.
- Open the cold-water valve.
- Leave the hot faucet open until water runs steadily with no air spurting.
- Only then turn the heater back on: relight following the label for gas, or switch on the breaker for electric. See no hot water after flushing a water heater if it doesn’t heat afterward.
If the drain valve leaks afterward
Plastic drain valves often drip after being opened. A cap on the hose threads can stop a slow drip temporarily; replacing the valve is a minor repair. See water heater plastic drain valve dripping.
Frequently Asked Questions
Q: Do I need to drain the tank to fix a leak? A: Not always. If the tank itself is leaking, close the cold-water valve and turn off the heater first; draining reduces the amount of water that can escape while you wait for the plumber.
Q: Can I drain into a toilet? A: Yes, into the bowl, if the water has cooled. Flush as needed so it doesn’t overflow, and don’t leave the hose unattended.
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 51: puddles around a heater (opens in a new tab)Common water-leak sources and the distinction between fittings and a failed tank.
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