Service manual

38
11.2 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 this
form of quartz of 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.
o Use NIOSH certified dust
respirator (N95). This type of
respirator is based on the OSHA
requirements for cristobalite at
the time this documentation 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://www.cdc.gov/niosh/homep
age.html. NIOSH approved
respirators, manufacturers, and
phone numbers are also listed
on this website.
o 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 water heater 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
11.3 PILOT BURNER
Turn the pilot firing valve to off position and
allow the appliance to try for ignition. Observe
the spark making sure that it is strong and
continuous.
If the spark is not acceptable the igniter will have
to be adjusted. This can be readily
accomplished after removing the main burner.
The spark gap should measure between 1/8” to
3/16”. Make sure that the electrode does not
appear overheated or fouled with carbon. It may
be necessary to clean the ignition electrode
using steel wool. Once the pilot appears to be
properly set, reinstall it into the appliance
making sure to properly tighten the pilot line
connection.
If the pilot is removed from the main burner in
the course of servicing the appliance, it is
important to replace all gaskets and seals.
These seals are intended to prevent the bypass
of air around the pilot.
Figure 26 – Pilot and Burner Box
Once the spark is satisfactory, open the pilot gas
and allow the pilot burner to light. Once air has
been purged from the pilot line, the pilot flame
should appear almost instantly at the initiation of
spark. Cycle the pilot several times to confirm
reliability. A properly set pilot will appear blue
and will engulf the igniter and ground electrode.
Open the firing valve and allow the main burner
to light. The pilot must not extinguish. After
running for 15 minutes, cycle the appliance to
ensure that the pilot remains stable.