Check the oil pump pressure. Standard operating pressure is 100 PSIG.
After reaching steady state, take a smoke test. If not indicating a trace, set the combustion air controls to provide a trace.
Typically, the CO2 reading will range from 11.5% to 13.5%.
After the air adjustments have been completed, and the air shutter or air ad- justment plate has been secured, re- check the breech draft and take another smoke test to ensure that the values have not changed.
SMOKE TEST NOTE:
If oily or yellow smoke spots are found on the smoke test filter paper, it is usu- ally a sign of unburned fuel. This indi- cates poor combustion. This type of problem may be caused by excess draft, excess air, or contaminated fuel. Do not ignore this indicator.
STACK TEMPERATURE:
Stack temperature will vary depending on fuel input, circulating air blower speed, and burner set up, etc. In gen- eral, stack temperature should typically range between 380°F to 550°F, assum- ing that the combustion air is approxi- mately room temperature (65°F - 70°F). In general, lower stack temperature indi- cates greater efficiency; however, ex- cessively low stack temperature can lead to condensation forming in the chimney and / or venting. Sulphur and similar contaminants in the fuel oil will mix with condensation to form acids. Acids and resultant chemical salts will cause rapid deterioration of the chimney and venting components, and may attack the fur- nace.
If the flue gases are below the range, it may be necessary to slow down the blower fan. If the flue gases are above the range, the blower fan may require speeding up. Stack temperature varies directly with the system temperature rise. System temperature rise is the difference between the furnace outlet temperature and furnace inlet temperature as meas- ured in the vicinity of the connection be- tween the plenum take-offs and the trunk ducts. Typical temperature rise values range between 70°F and 85°F.
If the venting from the furnace to the chimney is long, or exposed to cold am- bient temperatures, it may be necessary to use L-Vent as the vent connector to reduce stack temperature loss to prevent condensation. The venting should be inspected annually to ensure that it is intact.
FURNACE INSTALLATION SET-UP
The furnace must be set up as the final step in the installation.
A)The oil burner must be set up follow- ing the procedures outlined above.
B)The furnace should operate within a temperature rise of 85°F ±15°F. To de- termine the temperature rise, measure the supply air and return air tempera- tures when the furnace has reached steady state conditions. This is the point at which the supply air temperature stops increasing relative to the return air tem- perature. The furnace may have to run 10 to 15 minutes to reach steady state conditions. The measurements may be made with duct thermometers or thermo- couples used in conjunction with multi- meters with temperature measurement capabilities.
The return air should be measured at a point where the thermometer will be well within the air stream near the furnace return air inlet. Actual location is not par- ticularly critical; however, avoid locations where the temperature readings could be affected by humidifier bypass ducts, the inside radius of elbows, etc.
The supply air temperature should be measured at a point where the ther- mometer will be well within the air stream near the furnace supply air outlet. Usu- ally, the side mid-point of the supply air plenum take-off is ideal, providing it is out of the line of sight to the heat ex- changer. If the thermometer is within the line of sight of the heat exchanger, the supply air readings may be skewed by radiant heat from the heat exchanger. If the plenum take-off is unsuitable, the supply air temperature may be measured within the first 18 inches of the first seg- ment of supply air trunk duct.
If the temperature rise is outside the rec- ommended range, it may be adjusted on direct drive equipped units by selecting alternate circulation fan motor speeds, on belt drive equipped units by adjusting the variable speed motor pulley. If the temperature rise is too high, speed the fan up. If the temperature rise is too low, slow the fan down.
C)Keep in mind that the stack tem- perature varies directly with the tempera- ture rise. The higher the temperature rise, the higher the stack temperature will be, resulting in lower efficiency. The lower the temperature rise, the lower the stack temperature will be, which, in some cases, may allow condensation to form in the chimney and other vent parts.
D)Test the high limit control to ensure that it is operating correctly. For direct drive equipped units, this may be done by temporarily removing the circulator fan heating wire or neutral wire. For belt drive equipped units, temporarily remove the fan belt. Turn of electrical power to the furnace before working with the mo- tor wires or fan belt. Be sure to protect any removed wires from shorting out on metal furnace parts. If the high limit test is successful, shut off the electrical power to the furnace, restore the proper motor wiring. Finally, restore power to the furnace.
E)Adjust the “Fan Off” setting on the L6064A or L4064W fan limit controller. In most cases, the “Fan Off” temperature should be 90° to 100°F as indicated on the thermometer used to measure the supply air temperature. Once the “Fan Off” setting has been established, set the “Fan On” setting. In most cases, the “Fan On” setting should be approximately 30°F higher than the Fan Off” setting.
NOTE: The L4064W fan/limit controller has an auxiliary “fan on” function that activates when the thermostat is calling for heat. The controller is designed to start the circulating fan in 20 to 30 sec- onds. Adjust the “fan on” setting on the controller dial 30°F higher than the “fan off” setting even though the circulating fan will normally be started by the auxil- iary “fan on” function.
F)Operate the furnace through a minimum of three full heating cycles. During this time, check for fuel oil leaks, gross air leakage from the supply air ductwork, unusual noises originating anywhere within the heating system which may cause some concern or an- noyance to the home owner, etc.
G)Be sure that the homeowner is familiar with the furnace. The homeowner should be aware of the location of electrical circuit breaker or fuse, the location of any electrical switches controlling the furnace, the location of the oil tank shut-off valve and how to operate the valve. The home- owner should be informed where the oil tank gauge is located and how to read it.
It would be beneficial to review safety issues with the home owner, such as the danger of storing combustibles too close to the furnace, hanging anything on the furnace vent pipe, and especially the dangers of indiscriminately pressing the burner reset button.
