An inline heater is a heating device in a tub that heats the water in the tub as it begins to cool down. Using an inline heater in a tub means you don’t have to keep refilling the tub with warmer water. This can make a difference in your hot water cost if someone in your household likes to take long soaks in the tub, or if someone in your household uses a whirlpool bathtub for relaxation or for hydrotherapy. Use of an inline heater reduces both the amount of hot water your water heater must generate and the amount of water you use in the tub with each usage. Depending upon the size of your tub and upon frequency and duration of use, you can expect to recover the cost of the inline heater in about 5 years in reduced use of your hot water heater and use of less water per use of the tub with average use. You may recover the cost more quickly if someone in your household uses a whirlpool tub for therapeutic purposes.

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