How to Heat a Pool with a Home Water Heater

Have the prices for new pool heaters driven you to take drastic measures to heat your pool? Before you consider the unthinkable, attach a hose to that water heater and have your friends over for an early season pool party. For the price of a specialty hot water hose you can heat a small above ground pool and more than adequately heat an inflatable pool.

Great backyard with swimming pool. American Suburban luxury house
credit: irina88w/iStock/GettyImages

Before installing your hot water hose (photo at left) check the current pool water level. If the pool is full you can empty it until you see that the water level has dropped at least two to three inches.

Locate the hot and cold water valve that leads to your washer machine (see caption). Push the valve lever up to temporarily cut off the water supply to the washer machine. Most valves have arrows pointing to both "on" and "off" positions.

Begin to unscrew the hot water hose (use pliers if needed). In most cases this hose will be on your left (see caption). Next screw in the hot water garden hose to the now exposed hot water junction. Make sure the hose is on hand tight with one last rotation using pliers.

With the hot water hose properly attached you can unravel the other end of the hose and put it in a safe position that will stay stationary over the edge of your pool. Make sure there is no one in the pool for the first time heating your pool this way.

Go back to your washer machine to turn the valve back down to the on position which will return the flow of water to your washer machine and now to your swimming pool as well. Then check back at the pool to see if it is hot water coming out of the hose. If it stays cold than just simply shut off the valve lever again and switch the hoses around so that the cold water hose is attached to the washer machine and vice versa.

Partially close the throttle knob that is usually located on the copper pipe above the valve (see caption). This will prevent the hot water from leaving the water tank too quickly allowing you to leave the valve on all day (if needed) and the water will never turn cold. Another strategy is to intermittently open and close the valve as water begins to turn from hot to warm, then wait 20 minutes to allow the water tank to recharge. This obviously takes closer monitoring however.

Keep filling with the hot water hose until the water level of your pool is back to normal operating level. Simply replace the original hose back onto the washer machine when you are done filling the pool.

Jump in and enjoy!!! Keep in mind that it may take a few days to figure out the heating capabilities of your water heater. Results will vary depending upon pool size and climate. For cooler climates this method will work best if you start heating one or two days before the weekend pool party.