Copper Kettle Wood-Fired Water Heater                               

Our  Copper Kettle Hot Tub Heater is a precision Japanese built wood-burning water heater designed hot tubs and other hot water heating needs. It circulates water using the principal of thermosyphoning  (water movement created by rising hot water), eliminating the need for an expensive circulating pump or any electricity at all. This stand-alone feature opens up a whole new world of possibilities for alternative energy hot tub users.

The Copper Kettle can also be used for other types of hot water heating into an open tank.

With the Copper Kettle you can have the basic soaking tub without the need for expensive pumps, unwanted harsh chemicals, or annoying high maintenance. You can easily retrofit an existing tub or put together a low-cost soaking tub, using our Cedar Wooden Hot Tubs or one of our durable colored stock tanks.

We recommend using a  200 to 300 gallon stock tank for your hot tub because... they are inexpensive, easy to drain and easy to clean and sanitize. We sell beautiful wood tubs or, one of our economical colored UV resistant poly tubs.


Installation requires these four basic steps:
(1) Preparing a brick or cement foundation next to the hot tub to receive the Copper Kettle heater.
(2) Cutting 1 7/8-inch holes in the side of the tub wall for thru-wall ports.
(3) Installing piping to connect heater and tub.
(4) Installing the stove pipe, (8 feet recommended)

The Copper Kettle heater operates like a conventional wood stove, achieving the fastest heating rate from dry hardwoods. It uses 17-inch wood with an 18-inch x 14-inch x 14-inch firebox. The most efficient heating comes from using 16-inch x 1 1/2-inch x 1 1/2-inch wood, loaded at 45 min. intervals.

The Copper Kettle has a high and low speed draft for controlling the heating rate. It runs with the draft wide open for fast heating, and closed down to maintain temperature once the water is hot.

• High Quality Stainless Steel body
• 1/8-inch steel stove front
• Heavy cast iron door and grates
• Generous size 20 inches high and 15 inches in diameter
• Vented smoke-outlet for secondary combustion.
• 3/4-inch drain for freeze protection.
• An ash drawer for easy removal of ashes.

Heating Rate Information
The heating rate is variable depending on dryness and type of wood, frequency of loading, etc., the average heat output of the Copper Kettle is 40,000 BTU’s. A 200-gallon tub can be heated at approx. 25Fº per hour.

Caution: The heat output of the Copper Kettle increases after an initial 45-min. warm-up period that heats the stove body and establishes a bed of coals.

Heating Schedule
55ºF to 105ºF

Gallons Time
100 1 1/2 hours
200 2 1/2 hours
300 3 1/2 hours
400 5 hours

Japanese Heater Pricing




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