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The coils in a heater can be used to heat the water in your existing hot water supply tank.
If the tank is mounted above the lower coil the water will circulate on its own from the
tank into the hot coils and rise back into the tank. If the 2 turn coil is used on smaller
tanks, it will make the water too hot and the pressure/temperature relief valve will release
too often. In this case the hot supply line will need a cooling radiator to dissipate the extra
heat. The Radex heater will take the extra heat out of the water and return the heat back
into the cabin. If a 1 turn coil is used with a larger tank the recovery time may take a long
time. The temperature of the water will change from the operating settings set on the
heater. When the coils are used in a hydronic system the temperature of the water will
vary from the speed of the water being circulated through the coils.
Coil Installation
It is best to order the heater with the coils installed but at a later date follow these
instructions
1. On the back of the outer heat shield are 2 obround holes. Use a marker to outline the
holes on the heater body.
2. Remove the 4 nuts holding the outer shield and open the front door to manipulate the
front and back shield off the heater.
3. Remove the 3 screws on the top and pull it off the top of the heater.
4. Drill pilot holes in the centers of the outlined holes then punch or drill (drill bit or hole
saw) 5/8 “ dia holes.
5. Place the drill bit or a 5/8” rod into the holes to bend upwards from the inside to shape
the holes to fit the coils through.
6. Fit the coils into the holes so the ends of the coils stick out at least 2” past the heater
body. Drill a hole and position the bracket that was included with the coil, to hold the coil
in place with a 1/8th drill bit. Use the #10 x 1 1/4" screw to screw down the 'L' shaped
bracket. Clamp down the coil between the two bracket pieces. This bracket keeps the coil
in place. It is important that the coil be installed so there is a constant rise in the tube as it
goes to the back of the heater. This aids in the movement of the water or glycol.
