Sterling QVOF - Manual (Page 2)

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The thermostat should be mounted away from the blower
air stream on an inside wall or partition approximately 5
feet above the floor.
3 – FUEL OIL PIPING
a) Gravity Systems
Gravity systems where fuel supply is on the same level
as unit, require one line from tank to burner. This should
be 1/2″ or 3/8″ O.D. tubing or 3/8″ iron pipe according
to local codes. There should be a hard seat globe valve
at tank. A Main line oil filter should be installed
immediately after valve. Another valve, either hard seat
globe or heat responsive, should be installed at burner.
Local codes must be adhered to.
b) Lift Systems
Lift systems where fuel supply tank is below unit, require
a two-pipe system. See Figure 1.
Suction and return lines should originate no less than
2″ nor more than 4″ from bottom of fuel tank. If code
permits, 1/2″ O.D. soft tubing should be used. A double-
tapped bushing should be used in tapping of tank with
a slip connector so that both lines are continuous from
bottom of tank to inside of building.
A good quality ball check valve should be in the suction
line immediately inside of building.
Care should be exercised in installing lines in tank so
that they do not curl up inside of tank.
Lines should continue to burner either as copper tubing
or black pipe, depending on local codes, and should be
run straight and direct, eliminating need for bends or
elbows as much as possible. Lines should be securely
fastened to eliminate vibration and/or sagging.
Be sure bypass plug is installed in proper place, tightly
secured. See instruction sheet attached to pump for
more detail. On all connections, use oil resistant joint
compound. Either hard seat globe valve or heat
responsive valve (Firomatic or equal), depending on
code, should be installed in suction line as close to
pump as practicable.
A boost pump should be used on multiple unit heater
installations, or where an installation has more than a
15 foot lift (measured from the suction line in fuel tank
to the fuel unit on the burner). See Figure 2
Sterling oil powered Unit Heaters are shipped in a heavy
duty reinforced corrugated shipping crate. Upon receiving
your unit, a careful inspection of this crate should be
made to ascertain if there is any damage either external
or concealed.
All Unit Heaters come completely assembled and wired.
GENERAL INFORMATION
Oil Fired Unit heaters are designed to be suspended.
However, they can be installed on approved fire-resistive
slabs or supports having no combustible material against
the underside of the unit. Other clearances to
combustible sources should be not less than 6″ from
sides and top and 18″ from flue pipe in any direction.
When suspending the unit from a ceiling, an allowance
of 18″ from the top of the unit should be made to
accommodate a barometric draft regulator.
Unit Heaters should not be subjected to negative
pressures (drafts) created by room or building exhaust
fans. Sufficient air for combustion is an important
consideration.
Special attention must be given to those installations,
such as service stations and warehouses, where the
units have short stacks since the draft may not be
adequate.
When the vertical distance from the fuel supply tanks to
the fuel unit on the burner is more than 15 feet, or
when a multiple installation is required, the fuel system
should include a boost pump. See Figure 2.
INSTALLATION PROCEDURE
1 – HANGING OF UNIT
Welded to the top of the heat exchanger at each corner
is a 3/4″ pipe coupling which will accommodate a
standard 3/4″ pipe nipple. There are many ways the
suspension of a unit can be accomplished. However,
care should be taken to be sure the supporting beams
or girders are of ample strength to support the weight
of the unit. It is good practice to distribute the weight
over several girders rather than depending on one.
2 – WIRING
As this is a prewired unit, all controls, with the exception
of the thermostat are mounted and wired. 115 volt
service to utility box on unit heater is required. Unit
should be fused independent of other fixtures,
equipment, etc. There is a service switch on the unit.
An additional switch should be provided at the room or
building entrance.