Installation & Operation Manual
77
12
Maintenance
(continued)
BURNER
BURNER
GASKET
INSULATION,
BURNER DOOR
GASKET,
BURNER PLATE
BURNER PLATE
Figure 12-2 Burner Assembly
Check flame signal
1. At high fire the flame signal shown on the display should
be at least 10 microamps.
2. A lower flame signal may indicate a fouled or damaged
flame sense electrode. If cleaning the flame sense electrode
does not improve, ground wiring is in good condition,
and ground continuity is satisfactory, replace the flame
sense electrode.
3. See Section 3 - Troubleshooting of the Knight Wall
Mount Service Manual for other procedures to deal with
low flame signal.
Oiled bearing circulators
1. The circulator shipped with the Knight wall mount boiler is
water-lubricated. No oiling is required.
2. Check other circulators in the system. Oil any circulators
requiring oil, following circulator manufacturer’s
instructions. Over-oiling will damage the circulator.
3. Replace the boiler front access cover.
The boiler contains ceramic fiber materials.
Use care when handling these materials per
instructions in the Service Manual. Failure
to comply could result in severe personal
injury.
WARNING
Cleaning boiler heat exchanger
1. Shut
down
boiler:
• Follow the “To Turn Off Gas to Appliance” instructions
for the boiler in Section 10 - Startup.
• Do not drain the boiler unless it will be exposed to
freezing temperatures. If using freeze prevention fluid
in system, do not drain.
2. Allow time for the boiler to cool to room temperature if it
has been firing.
3. Remove the nuts securing the heat exchanger access cover
to the heat exchanger and set aside.
4. Remove the heat exchanger access cover and burner.
5. Remove the condensate trap from the bottom of the boiler.
Place a bucket underneath the condensate fitting attached
to the heat exchanger.
6. Use a vacuum cleaner to remove any accumulation on the
boiler heating surfaces. Do not use any solvent.
7. Using a clean cloth dampened with warm water, wipe out
the combustion chamber. Rinse out debris with a low
pressure water supply.
8. Allow the heat exchanger to thoroughly dry.
9. Perform start-up and check-out procedures in the Check
Flame and Combustion - Section 10 - Startup on pages 59
and 62 of this manual.
10. Replace the burner, access cover and condensate trap.
Restore boiler to operation.
* Do NOT use a metal brush.
CAUTION
Review with owner
1. Review the Knight Wall Mount User’s Information Manual
with the owner.
2. Emphasize the need to perform the maintenance schedule
specified in the Knight Wall Mount User’s Information
Manual (and in this manual as well).
3. Remind the owner of the need to call a licensed contractor
should the boiler or system exhibit any unusual behavior.
4. Remind the owner to follow the proper shutdown procedure
and to schedule an annual start-up at the beginning of the
next heating season.
Perform start-up and checks
1. Start boiler and perform checks and tests specified in
Section 10 - Start-up.
2. Verify cold fill pressure is correct and that operating
pressure does not go too high.
Check burner flame
1. Inspect flame through observation window.
2. If the flame is unsatisfactory at either high fire or low fire,
turn off boiler and allow boiler to cool down. Remove the
burner and clean it thoroughly using a vacuum cleaner
or compressed air. Do not use compressed air to clean
burner if performed inside a building.
3. Remove the burner, reference FIG. 12-2 (page 77).
4. When replacing the burner, ensure gasket is in good
condition and positioned correctly (FIG. 12-2).
