Lanair DHI 300 - Manual (Page 28)

Section 10 - Priming The Fuel Pump
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Priming The Fuel Pump
1. The fuel level in the supply tank must be
above the check valve on the pick-up tube.
2. Remove the bowl of the suction line strainer,
and fill with clean fuel. Replace the strainer
bowl.
3. Remove the two yellow wires from the F-F
terminal on the oil primary control. Install a
jumper wire between the F-F terminals (see
Figs. 8 & 9).
4. Adjust the air filter/regulator on the heater
to 15 PSI.
5. Remove the fuel supply line from the burner,
and position a container to catch the fuel.
6. Back the thumb screw out (CCW) on the by-
pass regulator until it is free, the turn (CW)
two turns to seat the diaphragm.
7. Loosen the bleeder screw on the pump one
turn, and attach a piece of 3/16” ID clear
plastic tubing. The tubing should be long
enough to allow the fuel to be returned to
the tank.
8. Turn the room thermostat above room temperature, or to the “ON” position.
9. Momentarily disconnect one end of the jumper wire at the F-F terminals on the oil pri-
mary. The fuel pump will now start.
10. Observe the clear tubing attached to the bleeder screw on the pump. When a steady
stream of fuel (no air bubbles) flows close the bleeder screw. Remove the tubing from
the bleeder screw.
11. Observe the end of the fuel supply line that is disconnected from the burner. Allow a
steady stream (no air bubbles) of fuel to flow into the container for several minutes. This
will flush any debris from the fuel line that could potentially plug the nozzle. The vacu-
um gauge reading should not exceed 5” HG of vacuum.
Figure 8
Remove two yellow wires
Figure 9
Install jumper wire
Section 11 - Burner Start-Up Procedure
QUESTIONS?... Contact Customer Service at 1-800-753-1601 M-F 8:00 am- 4:15 pm CST
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15. Adjust the fuel pressure gauge on the left side of the burner to read.
NOTE: Adjust the thumb screw on the fuel bypass regulator clockwise to increase pressure,
and counter clockwise to decrease pressure to the burner. The oil pressures listed above are a
starting point, you may need to adjust from there when VISUALLY SETTING THE FLAME
(See page 29-31, flame adjustment).
16. Adjust the barometric damper to obtain a draft of -.06 W.C. while the heater is hot and
operating.
NOTE: It is VERY IMPORTANT that the barometric damper is set to the required settings to
ensure the natural draft of exhaust gases (see sections 4 & 5).
17. Depending on the type of fuel used, the elevation, temperature, and oil viscosity, the
combustion air baffle will need to be adjusted for optimum performance (See page 29-
31, flame adjustment).
18. When the room thermostat setting is met
the burner will shut off, but the fan will con-
tinue to operate until the cabinet tempera-
ture drops to 90º F.
No. 1 & No. 2 Fuel Oil Approved Waste Oil
Model DHI-300 4.5 (4-1/2) LBS. 5-6 LBS.
The combustion air baffle is NOT factory set
!
Clockwise:
Increase fuel
pressure Counter
Clockwise:
Decrease fuel
pressure
Fuel By-Pass Regulator
Thumb Screw
Lock Nut