Field Controls WML-C Furnace User Manual


 
30318 R4 9/9/2005
12
should be checked to ensure that all fan
speeds are operating properly.
OPERATING INSTRUCTIONS
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
Honeywell ST9103 has a fixed fan delay
on time of 30 seconds after the burner
ignites. 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 30, 60, 90 or
120 seconds.
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 Honeywell ST9103 has an
adjustable fan off time of 60, 90, 120 and
150 seconds that is set by selecting a
dipswitch combination on the control
board. Similarly the United
Technologies 1158-120 has an
adjustable fan off time of 2, 3, 4 or 6
minutes 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. The system
temperature rise, the difference in
temperature between the supply air and
return air, should be within the indicated
range on the appliance rating plate.
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".
NOTE: If the furnace is to be shut down
for an extended period of time, close the
oil supply valve to the oil burner.
DO NOT ATTEMPT TO START THE
BURNER WHEN EXCESS OIL HAS
ACCUMULATED, WHEN THE
FURNACE IS FULL OF VAPOUR, OR
WHEN THE COMBUSTION CHAMBER
IS VERY HOT. NEVER BURN
GARBAGE OR PAPER IN THE
FURNACE, AND NEVER LEAVE
PAPER OR RAGS AROUND THE UNIT.