by Quick answer: Unplug the heater first, strip the bed, and open the fill valve. Then either siphon the water out with a garden hose (the drain end must sit lower than the bed) or use an electric waterbed pump for speed. Reseal the valve the moment it's empty.
By the MattressNut editorial team · Updated June 2026
Draining a Waterbed Explained
Whether you're moving, replacing, or storing a waterbed, the job comes down to safely getting the water out without flooding the room. There are two reliable methods: a gravity siphon using a garden hose, which is cheap and needs little supervision, and an electric pump, which is faster but must be watched constantly.
Step by Step
- Strip the bed. Remove all bedding, protectors, and pads down to the bare vinyl mattress.
- Unplug the heater. This is the critical safety step. Running the heater on a draining mattress can damage the bed and is a shock hazard. Disconnect any other power too.
- Lay down towels. Place towels around the bed to catch spills, and gather your supplies: a long garden hose, the drain valve cap, and optionally a wet/dry vacuum.
- Open the fill valve. It's usually at the foot of the bed. Remove the cap and "burp" out trapped air. If you're alone, sweep a broom from the head of the bed toward the valve to push the air bubble out.
- Choose your method. See both below.
Garden-hose siphon (no pump): Connect the hose to the drain valve and run the other end to a lower drain, tub, or outdoors. The drain end must sit lower than the bed or it won't flow. To prime the siphon, briefly connect a faucet to push out the air in the hose, then disconnect and let gravity pull the water out.
Electric pump (fastest): Pumps can be rented or bought from a waterbed dealer. Roughly, a king softside takes about 30 minutes and a king hardside about 50. Never run the pump dry: more than about 60 seconds with air running through it can burn out the impeller or the pump itself.
Tips & Mistakes to Avoid
As the water level drops, the mattress gets heavy and awkward. Gently roll it toward the valve to push remaining water out, and use a wet/dry vacuum to pull the last residual water from the valve.
Reseal the valve immediately once empty, and don't let air rush back in. Keeping the vacuum holds the internal baffling in place and reduces the chance of the mattress going "sour" from air, water, and bacteria mixing. If you're storing it, clean the vinyl first and keep it somewhere dry, dark, and stable in temperature, since old vinyl can crack when refolded.
The Saatva Angle
Many people drain a waterbed because they're moving on to a conventional mattress, which is far easier to live with: no draining, no leaks, no heater. If that's the next step for you, a supportive innerspring or hybrid is the most common upgrade from a waterbed.
Bottom Line
Drain a waterbed by unplugging the heater, opening the valve, and either siphoning with a hose or using a pump. Keep the drain end low, never run a pump dry, and reseal the valve the instant it's empty.
Bottom line: Unplug the heater, siphon or pump the water out to a lower drain, and cap the valve immediately to protect the mattress.
Related: our full Saatva mattress review.