Heater must be under supervision when it is in use
Read the technical descriptions before installing the heater
Read the manual before starting the heater
Improper use of the heater can be dangerous
The heaters chimney pipes, frame and fire door can become very hot during use.
Keep children away from the heater.
Wood-burning water heater
This is a precision-built water heater, especially designed for Hot Tubs. Water
is self-circulating using the "thermo siphon" principle. Hot water rises and
creates low pressure, which sucks the water from below. This eliminates the
need for a circulation pump and electricity, making it possible to heat the
water with the heater placed externally. One great advantage is that there will
be more space in the tub, making it possible to choose a smaller model.
Both the outer stove body and firebox are made of stainless steel. The frame
and doors are made of cast iron, which will guarantee you years of trouble-free
use. The heater must be drained via the drain hole after every use (D).
The heat from the fire is efficiently transferred to the water through a unique
sophisticated construction, making the entire firebox a heat-transferring
surface. The total heating efficiency is 14.9 kW.
To get a good enough water circulation going the heater must be placed atleast
15 cm lower than the foundation the hot tub stands on.
Installation
Chofu Wood is connected to a hot tub (smallest diameter 150cm) with a connection kit (CHDW, CHS),included in a complete hot tub package. It is not included when ordering only the heater but can be ordered separately as an accessory, the kit consists of 50 mm PBC tubing, flexible rubber hoses including clamps, one straight connection for the side of the hot tub and one 90° for the base.
Procedure:
Place the heater on an even wood, brick or concrete surface. The heater should
be placed 10 cm lower than the Hot Tub to ensure that the upper pipe is
diagonal. This is important for circulation and to ensure that the water drains
out of the heater during cold weather.
Drill a 60 mm hole for the upper connection pipe (outflow) in the side of the
Hot Tub, 190 mm above the base. Drill a similar hole at the base on the
opposite side of the hot Tub for the heater inlet pipe.
The straight connection, including pipe, should be screwed tightly to the side
and the other connection to the base.
Connect the black rubber pipes to the heater and pipes. It will be easier to
connect the pipes if they are oiled with cooking oil. Tighten using the
included hose clamps.
Operation
The Chofu Wood heater operates as a conventional wood stove, achieving the
fastest heating rate from dry wood. The firebox is 46 cm long and 36 cm in
diameter. The most efficient heating comes from using dry wood, 40-43 cm long
chopped into a thickness of 4 X 4cm. One load burns for approximately at 45
min.
The Chofu Wood heater has a high and low-speed draft for controlling the
heating rate. It’s run with the draft wide open for fast heating, and slowed
down to maintain temperature once the water is hot.
Chofu Chimney Pipe holder
Firmly press the chimney pipe in place on the black adapter on the burner. Then assemble the ring with shackles that keep the chimney in place. NOTE! This has to be firmly assembled so the chimney cannot move. Fasten the accompanying "hooks" in the burner and ring. NOTE! Turn the seam on the pipe backwards.
Design
The design of the heater is made so that it will lean slightly downwards in the
front when it stands on a stable and even base. Never put the heater in sand or
any other type of soft foundations as it will cause an airpocket that prevents
proper circulation and will damage the heater.
If the heater is installed with a pump (for instance for a pool) the connection
must be outfitted with an adjustable valve on the suction side that enables you
to regulate the waterflow and pressure. Too high water flor and pressure can
damage the heater. Position the position the valve so that the hot water coming
from the heater stays around 50-60 degrees celsius.
Features
• Weather resistant construction
• Stove body of stainless steel
• Frame and doors of cast iron
• Connection parts to the Hot Tub
• Large fire place
• Vented smoke outlet for a secondary combustion
• Discharging vent for the water in order to protect the heater from frost
Specifications
46 cm (height) x 58 cm (length) x 41 cm (width)
Weight: 26 kg
Firebox: 46 x 36 x 36 cm
Heat exchanger surface: 0.85 m²
Heating
The heating effect varies according to the quality of the wood and how often
you put in more wood. The approximate heating effect for the Chofu Wood stove
is 14.9 kW. The heating rate of 1 000 litres of water is approximately 12° C
per hour.
Hot Tub model
Amount of water
Start temperature
Approx. Heating time to 37 °C
HT150
1200 L
10 °C
2 hours
Note! If seawater is used, rinse the heater with fresh water after use!
The same procedure is needed for chlorinated water or if other chemicals are
used.
Winter use
If there is a risk of freezing damage then the heater must be drained of water
after use. Self circulation will cease when the wood has burnt out and the
small amount of water remaining in the heater can easily freeze and cause
damage to the heater. To keep the water in the hot tub there is a rubber plug
complete with accessories. See images below. You can also supply the pipes with
valves that can be opened and closes. Depending on how this is arranged it can
become necessary to insulate the pipes and valves for the bath.
HINT!
The wood heater has a large external surface that is in direct contact with air
and therefore it is recommendable to insulate the exterior with, e.g. some kind
of “flexible insulation material” which helps to shorten the warming up phase
considerably.
WARNING!
The white “distributor pipes” has to be connected when the heater is in use.
Don’t put fingers or toes in the “distributor pipe”.
The heater may not be used till the water level rises above the highest pipe.
Get used to empty always the heater when it won't be used especially when the
temperature sinks below 0.
When using saltwater the heater should always be rinsed with fresh water after
each use.
The same applies for chlorinated water or something similar when chemicals are
used.
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