Harman Stove Company Hot Air s SF1500A - Manual (Page 16)

16
3-90-70744R11_05/13
Special Instructions
Hot Water Out
Cold Water In
Pressure
Relief Valve
Existing Water
Heater
Rear Of
Furnace
Automatic
Air Valve
Pressure
Relief Valve
(Must be within
2 feet of coil)
10 Feet Maximum
Drain
Valve
1
2
3
3
4
5
Plumbing diagram For Thermo-Siphon method - maximum distance = 10 Feet
Place one of the supplied nuts on each leg of the coil. Place the coil through the holes on the back of the furnace, and adjust
the nuts so that the pipes stick out about 1¼ to 1½ inches from the rear of the furnace. Place the flat washers and gaskets
over each pipe and tighten the nuts. You are now ready to run the piping.
This simple method is the most economical. However, the existing water heater must be less than 10 feet from the furnace.
The water inlet, where the Temperature / Pressure Relief valve is located, must be higher than the top leg of the water coil.
The water heater should be elevated, if necessary, to allow for proper thermo-siphon action.(The method by which hot water
will circulate automatically through the system.)
A. Shut off the water heater and the water supply to it. Drain the tank completely.
B. Remove the Temp. / Presure relief valve and discard. Install a short 3/4 in. nipple and tee (1) along with a new relief valve.
C. run 3/4 in. copper tubing between the water tank and the top leg of the coil. Install a 3/4 in vent elbow and automatic “float
type” air vent (2) in the high point of the line. Within 2 feet of the top leg of the coil, install a 150 lb. pressure relief valve
(5). Run 3/4 in. tubing from the release exit of both relief valves downward (3) so the hot water can escape in the event
of an overheat situation.
D. Remove the drain valve, at the bottom of the tank. Install a short 3/4 in. nipple and tee and re-install the drain valve to
the tee (4). Run 3/4 in. tubing between the drain / tee combination and the lower leg of the water coil. After all of the
connections are secured, refill the water tank. Turn on the water heater only after the tank has been completely refilled.
Coil Installation: