KeepRite F9MAC Series, Service And Technical Support Manual

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SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace: (F/G)9MAC
Specifications subject to change without notice.
440 04 4201 03 27
8. Turn on gas and electrical supplies to furnace.
9. Verify igniter operation by initiating control board self
− test
feature or by cycling thermostat.
10. Replace control door.
Flushing Collector Box and Drainage System
1. Turn off gas and electrical supplies to furnace.
2. Remove control door.
3. Disconnect pressure switch tube from pressure switch
port.
NOTE : Ensure the pressure switch tube disconnected from the
pressure switch is higher than the collector box opening or
water will flow out of tube.
4. Remove one of the collector box plugs from a port on the
upper corner of the collector box. (See Figure 1 )
5. Attach a funnel with a flexible tube to port on the collector
box.
6. Flush inside of collector box with water until discharge
from condensate trap is clean and runs freely.
7. Repeat steps 4 through 6 with middle plug on upper
corner of collector box.
8. Remove the pressure switch tube from the collector box.
NOTE : Do Not blow into tube with tube connected to the
pressure switch.
9. Clean pressure switch port on collect box with a small
wire. Shake any water out of pressure switch tube.
10. Reconnect tube to pressure switch and pressure switch
port.
11. Remove the relief tube from the port on the collector box
and the trap.
12. Clean the relief port on collect box and the trap with a
small wire. Shake any water out of the tube.
13. Reconnect relief tube to trap and collector box ports.
Cleaning Condensate Drain and Trap
NOTE : If the condensate trap is removed, a new gasket
between the trap and collector box is required. Verify a
condensate trap gasket is included in the service kit or obtain
one from your local distributor.
1. Disconnect power at external disconnect, fuse or circuit
breaker.
2. Turn off gas at external shut-off or gas meter.
3. Remove outer doors and set aside.
4. Turn electric switch on gas valve to OFF.
5. Disconnect external drain from condensate drain elbow
or drain extension pipe inside the furnace and set aside.
6. Disconnect the condensate trap relief hose from collector
box port and condensate trap.
NOTE : If condensate has a heat pad attached to the trap,
trace the wires for the pad back to the connection point and
disconnect the wires for the heat pad.
7. Remove the screw that secures the condensate trap to
the collector box, remove the trap and set aside.
8. Remove the trap gasket from the collector box if it did not
come off when the trap was removed.
9. Discard the old trap gasket.
10. Rinse condensate trap in warm water until trap is clean.
11. Flush condensate drain lines with warm water.
Remember to check and clean the relief port on the
collector box.
12. Shake trap dry.
13. Clean port on collector box with a small wire.
To re-install Condensate Drain and Trap:
1. Remove adhesive backing from condensate trap gasket
2. Install gasket on collector box
3. Align the condensate trap with the drain opening on the
collector box and secure the trap with the screw
4. Attach the relief hose to the relief port on the condensate
trap and collector box.
5. Secure tubing to prevent any sags or traps in the tubing.
6. Connect condensate drain elbow or drain extension
elbow to the condensate trap
7. Connect the leads of the condensate heat pad (if used)
8. Connect external drain piping to the condensate drain
elbow or drain extension pipe.
9. Turn gas on at electric switch on gas valve and at
external shut-off or meter
10. Turn power on at external disconnect, fuse or circuit
breaker.
11. Run the furnace through two complete heating cycles to
check for proper operation
12. Install outer door when complete.
Checking Heat Pad Operation (If Applicable)
In applications where the ambient temperature around the
furnace is 32 _ F (0 _ C) or lower, freeze protection measures are
required. If this application is where heat tape has been
applied, check to ensure it will operate when low temperatures
are present.
NOTE : The Heat Pad, when used, should be wrapped around
the condensate drain trap. There is no need to use heat tape
within the furnace casing. Most heat tapes are temperature
activated, and it is not practical to verify the actual heating of
the tape. Check the following:
1. Check for signs of physical damage to heat tape such as
nicks, cuts, abrasions, gnawing by animals, etc.
2. Check for discolored heat tape insulation. If any damage
or discolored insulation is evident, replace heat tape.
3. Check that heat tape power supply circuit is on.
Cleaning Heat Exchangers
The following items must be performed by a qualified service
technician.
Primary Heat Exchangers
If the heat exchangers get an accumulation of light dirt or dust
on the inside, they may be cleaned by the following procedure:
Figure 12 Cleaning Heat Exchanger Cell
NOTE : If the heat exchangers get a heavy accumulation of
soot and carbon, both the primary and secondary heat
exchangers should be replaced rather than trying to clean them
thoroughly due to their intricate design. A build − up of soot and
carbon indicates that a problem exists which needs to be