Bryant 935CA Installation, Start-Up, Operating And Service And Maintenance Instructions page 58

935CA: Installation, Start-up, Operating and Service and Maintenance Instructions
The igniter does NOT require annual inspection. Check igniter
resistance before removal, see Fig.
1. Turn off gas and electrical supplies to furnace.
2. Remove control door.
3. Disconnect igniter wire connection.
4. Check igniter resistance. Igniter resistance is affected by
temperature. Only check resistance when the igniter is at room
temperature.
a. Using an ohm meter, check resistance across both igniter leads in
connector.
b. Cold reading should be between 40 ohms and 70 ohms.
5. Remove igniter assembly.
a. Using a 1/4-in. driver, remove the two screws securing the igniter
mounting bracket to the burner assembly, see
1/4-in. length screws.
b. Carefully withdraw the igniter and bracket assembly through the
burner assembly without striking the igniter on surrounding
parts.
c. Inspect igniter for signs of damage or failure.
d. Inspect the igniter gasket. If damaged or missing, replace gasket
before reinstalling.
6. To replace igniter and bracket assembly, reverse items 5a through
5d.
7. Reconnect igniter harness to the igniter, dressing the igniter wires to
ensure there is no tension on the igniter itself, see
8. Turn on gas and electrical supplies to furnace.
9. Verify igniter operation by initiating control board self-test feature.
Run the furnace through two complete heating cycles to check for
proper operation.
10. Replace control door.
Flushing Collector Box and Drainage System
WARNING
!
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Turn off the gas and electrical supplies to the furnace and install lockout
tag before performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace.
1. Turn off gas and electrical supplies to furnace.
2. Remove control door.
3. Disconnect pressure transducer tube from pressure transducer port.
NOTE: Ensure the pressure transducer tube disconnected from the
pressure transducer is higher than the collector box opening or water will
flow out of tube.
4. Remove the collector box plug from the top port on the upper
corner of the collector box, see
5. Attach a funnel with a flexible tube to port on the collector box.
6. Flush inside of collector box with water until discharge water from
condensate trap is clean and runs freely.
7. Repeat steps 4 thru 6 with middle plug on upper corner of collector
box.
8. Remove the pressure transducer
NOTE: Do NOT blow into tube with tube connected to the pressure
transducer.
9. Clean pressure transducer port on collect box with a small wire.
Shake any water out of pressure transducer tube.
10. Reconnect tube to pressure transducer and pressure transducer port.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
73.
Fig. 73. Retain
Fig. 73.
Fig. 66.
tube from the collector box.
11. Remove the relief tube from the port on the collector box and the
trap.
12. Clean the relief port on collector 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. Reverse installation instructions found in Condensate Trap Section
to disassemble the condensate trap.
2. Use water or a slight brush to clean components. Do NOT cut into
glued PVC sections to service the trap.
3. Ensure all instructions, cautions, and warning from Condensate
Trap Section are followed when reassembling condensate trap.
Checking Heat Tape Operation (If Applicable)
In applications where the ambient temperature around the furnace is
32_F or lower, freeze protection measures are required. If this
application is one where heat tape has been applied, check to ensure it
will operate when low temperatures are present.
NOTE: The Heat Tape, 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
IMPORTANT: It is not recommended to clean the heat exchanger as
part of annual maintenance.
If there is reason to believe that primary heat exchanger is obstructed and
cleaning is needed, remove burner assembly to access heat exchanger
and follow steps below.
Once burner assembly is removed, gasket of the burner box MUST be
replaced with a new gasket.
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 corrected, such as improper adjustment of manifold
pressure, insufficient or poor quality combustion air, improper vent
termination, incorrect size or damaged manifold orifice(s), improper gas,
or a restricted heat exchanger (primary or secondary). Action must be
taken to correct the problem.
NOTE: Proper use of Personal Protective Equipment (PPE) must be
followed, including safety glasses, gloves, and dust mask when
removing and reinstalling the heat exchanger insulation assembly.
1. Turn off gas and electrical supplies to furnace.
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