Crest Audio FBN0751, Service Manual

Page: 35 / 56

2
Maintenance
(continued)
35
Service Manual
6. Use a vacuum cleaner to remove any accumulation on
the tube sheet surfaces. Do not use any solvent.
7. Brush the heat exchanger (tube sheet, combustion
chamber walls, and tube entry) while dry using a nylon
bristle brush.
Caution: DO NOT use a metal brush.
Re-vacuum the heat exchanger.
8. Finish cleaning using a clean cloth dampened with warm
water.
9. Temporarily remove the condensate drain line from the
condensate trap and route directly to a drain.
10. Rinse out debris with a low pressure water supply. The
water will drain through the condensate connection.
11. Allow the heat exchanger to thoroughly dry.
12. Reconnect the condensate drain line to the condensate
trap.
13. Close isolation valves on piping to isolate boiler from
system. Attach a hose to the boiler drain and flush boiler
thoroughly with clean water by using purging valves to
allow water to flow through the water make-up line to
the boiler.
14. When securing the burner, be sure to tighten the nuts as
instructed in the “Check Burner Flame” section on pages
33 and 34 of this manual.
15. Replace the burner mounting plate assembly and gas/air
manifold assembly. Ensure gaskets are in good condition
and positioned properly. Restore boiler to operation.
16. Perform start-up and check-out procedures in the Check
Flame and Combustion - Section 9 - Startup of the Crest
Installation and Operation Manual.
The boiler contains ceramic fiber
materials. Use care when handling these
materials per instructions on this page.
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 9 - 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 top access panel to remove the gas/air
manifold assembly.
4. Remove the nuts securing the burner to the burner
mounting plate. Remove the burner (reference FIG.
2-2 and follow the steps in
Check Burner Flame on pages
33-34).
5. Remove the nuts securing the burner mounting plate
from the heat exchanger and set aside. Remove the
entire burner mounting plate assembly.
Handling ceramic fiber materials
REMOVAL OF COMBUSTION CHAMBER
LINING
The combustion chamber insulation in this
appliance contains ceramic fiber material.
Ceramic fibers can be converted to cristobalite
in very high temperature applications.
The International Agency for Research on
Cancer (IARC) has concluded, “Crystalline
silica in the form of quartz or cristobalite
from occupational sources is carcinogenic
to humans (Group 1).” Normal operating
temperatures in this appliance are below the
level to convert ceramic fibers to cristobalite.
Abnormal operating conditions would have
to be created to convert the ceramic fibers in
this appliance to cristobalite.
The ceramic fiber material used in this
appliance is an irritant; when handling
or replacing the ceramic materials it is
advisable that the installer follow these safety
guidelines.

Avoid breathing dust and contact with
skin and eyes.
• Use NIOSH certified dust respirator
(N95). This type of respirator is
based on the OSHA requirements for
cristobalite at the time this document
was written. Other types of respirators
may be needed depending on the job
site conditions. Current NIOSH
recommendations can be found on
the NIOSH website at http://
w w w . c d c . g o v / n i o s h / h o m e p a g e .
html. NIOSH approved respirators,
manufacturers, and phone numbers
are also listed on this website.
• Wear long-sleeved, loose fitting
clothing, gloves, and eye protection.

Apply enough water to the combustion
chamber lining to prevent airborne
dust.

Remove the combustion chamber lining
from the boiler and place it in a plastic
bag for disposal.

Wash potentially contaminated clothes
separately from other clothing. Rinse
clothes washer thoroughly.
NIOSH stated First Aid.

Eye: Irrigate immediately.

Breathing: Fresh air.
WARNING