Operating instructions

The venting system should be cleaned and inspected for
signs of deterioration. Replace pitted or perforated vent
pipe and fittings. The barometric damper should open
and close freely.
All electrical connections should be checked to ensure
tight connections. Safety controls such as the high limit
controls should be tested for functionality. The fan control
should be checked to ensure that the fan on and off
delay function continues to start and stop the blower fan
at the optimal settings.
21. OPERATING INSTRUCTIONS (O4HD-091A-
12-FB AND O4HD-091A-14-FA-DV)
Before Lighting
Open all supply and return air registers and grilles.
Open all valves in oil pipes.
Turn on electric power supply
To Light Unit
Set the thermostat above room temperature to call for
heat. The burner should start. NOTE: It may be
necessary to press the RESET button on the primary
combustion control relay.
There will be a fan on time delay before the circulating
fan is energized. The United Technologies 1158-120
has an adjustable fan on time that is set by selecting the
dipswitch combination displayed in Chart 1. This fan on
delay can be set at 1, 2, 4 or 6 minutes.
Set the thermostat below room temperature. The oil
burner should stop.
The air circulation blower will continue to run until the
time off setting selected on the electronic fan timer
control times out. The United Technologies 1158-120
has an adjustable fan off time of 30, 60, 90 or 120
seconds. The fan timer control adjustments may be
altered if the air at the room registers is uncomfortably
high upon blower start up or shutdown.
The necessary adjustments to the fan control settings
should be determined by measuring the temperature of
the air in the supply air take-off, or within the first few
inches of the supply air trunk. The side mid point of the
transition is usually ideal, providing that the thermometer
probe is beyond the "line of sight" wherein false readings
from radiant heat could be observed. System
temperature rise is the difference in temperature
between the supply air and return air.
To check the operation of the limit switch, shut off power
to the furnace. Temporarily remove the neutral wire from
the direct drive blower motor. Restore the electrical
power to the furnace and set the thermostat above room
temperature.
After three or four minutes of burner operation, the limit
control should turn the burner off. When the limit function
test is complete, shut off electrical power to the
furnace, replace the neutral wire to the blower fan
motor, and then restore power. The blower fan will
start up immediately. Once the temperature has
dropped and the limit control has reset, the fan will
operate until the fan off time is achieved. The oil
burner will then resume operation and continue until
the thermostat is satisfied. Restore the thermostat
setting to a comfortable temperature.
To Shut Down Unit
Set the thermostat to the lowest possible setting.
Set the manual switch (if installed) in the Electrical
Power Supply Line to "OFF".
21. OPERATING INSTRUCTIONS (O4HD-
091A-V-FA)
Before Lighting
Open all supply and return air registers and grilles.
Open all valves in oil pipes.
Turn on electric power supply
To Light Unit
Set the thermostat above room temperature to call
for heat. The burner should start. NOTE: It may be
necessary to press the RESET button on the
primary combustion control relay.
There will be a fan on time delay before the
circulating fan is energized. The United
Technologies 1168-1 has an adjustable fan on/off
time delay that is programmed into the ECM motor,
and is set by selecting the SW4 DIP switch
combination displayed in Table A-10 page 15. Fan
on/off delay must be adjusted according to input
(nozzle size).
1. Set the thermostat below room temperature. The
oil burner should stop.
The air circulation blower will continue to run until
the blower off delay setting programmed into the
ECM motor times out.
To check the operation of the limit switch, shut off
power to the furnace. Temporarily remove the 5 pin
power connector plug from the ECM blower motor.
NOTE: Isolate the AC Line pins on the 5 pin
power connector with electrical tape to prev ent
electric shock hazard. Restore the electrical
power to the furnace and set the thermostat above
room temperature.
After three or four minutes of burner operation, the
limit control should turn the burner off. When the
limit function test is complete, shut off electrical
power to the furnace, replace the 5 pin power plug to
the blower fan motor, and then restore power. The
blower fan will start up immediately. Once the
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