a.With the oil shut off, remove the 1/8 in. NPT threaded pipe plug located on the lower rear side of the oil pump, refer to Figure 22. Attach a pressure gage, capable of measuring pressure in pounds per square inch gage, PSIG, in this opening, on the discharge side, of the oil pump.
NOTICE: It may be necessary to remove the oil pump to attach the plumbing required to connect a pressure gage to the pump.
b.Turn on the fuel oil and cause the appliance to activate the heating section by answering a “call for heat”.
NOTICE: It may be necessary to bleed air from the oil line before the burner can be fired.
c.Allow the heating section to operate for 10 to 15 minutes.
d.Note the oil pressure at the pump.
e.To adjust the pressure, use a common screwdriver to turn in the pressure adjustment screw, located on the upper front of the oil pump body.
f.Allow the fuel flow rate to stabilize for a moment. Recheck the oil pressure.
g.If required, repeat the oil pressure adjustment again.
h.When the input rate adjustment has been completed, shut off the fuel oil to the appliance. Remove the pressure gage. Reinstall the pipe plug using a thread compound resistant to the action of LP gases and fuel oil.
To insure the combustion air supply is adequate, it is now necessary to repeat the steps in the previous Initial Burner Adjustment section of this manual.
4. Setting Supply Air Temperature Rise:
: To avoid injury from moving parts or electrical shock, shut off the power to the appliance before removing supply air blower compartment door and servicing this appliance.
All OL6 models are designed and wired at the factory for a blower speed during heating that should result in an approximate temperature rise of 65°F. The temperature rise through the heating section, for any given blower speed, may vary depending on a number of factors. A few of these factors are variations in, the actual resistance of the duct system to airflow at any time, the return air temperatures, and the fuel oil heating value.
Also, fouling of the heat exchanger surfaces will reduce temperature rise. In general, a lower temperature rise through the heating section will result in higher heating efficiency.
Temperature rise = supply air temperature - return air temperature.
After 15 to 20 minutes of continuous operation, the temperature rise through the furnace must fall within a range of 50° to 80° F. If the outlet or supply duct temperature is too high, check to make sure the return air filter is clean, the return air registers are free from obstruction, the outlet registers are properly adjusted and clear, and the supply and return air ducts are open. The circulating air blower is not moving enough air if the supply air temperature is still too high. Before proceeding further, turn off the power supply to the appliance and remove the vestibule cover. The speed of the blower must be increased by changing the switch setting on the control board, please refer to Figure 18.
42
