Please Read Before Proceeding; Handling Ceramic Fiber Materials - A.O. Smith XWH 150 Service Handbook

PLEASE READ BEFORE PROCEEDING

Installer – Read all instructions, including this Service Handbook and the XP Water Heater Instruction Manual,
before installing. Perform steps in the order given. Have this water heater serviced/inspected by a qualifi ed
service technician at least annually. Failure to comply with the above could result in severe personal injury,
death or substantial property damage.

HANDLING CERAMIC FIBER MATERIALS

REMOVAL OF COMBUSTION CHAMBER LINING
The combustion chamber insulation in this appliance contains ceramic fi ber material. Ceramic fi bers 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 fi bers to cristobalite. Abnormal operating conditions would have to be created to
convert the ceramic fi bers in this appliance to cristobalite. The ceramic fi ber 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 certifi ed 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://www.cdc.gov/niosh/homepage.html. NIOSH approved respirators,
manufacturers, and phone numbers are also listed on this website.
• Wear long-sleeved, loose fi tting 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.
Note: When calling or writing about the water heater – Please have the water heater model and serial
number from the water heater rating plate. Consider piping and installation when determining water
heater location (see the XP Water Heater Instruction Manual). Any claims for damage or shortage in
shipment must be filed immediately against the transportation company by the consignee.
When servicing water heater –
• To avoid electric shock, disconnect electrical supply before performing maintenance.
• To avoid severe burns, allow the water heater to cool before performing maintenance.
Water heater operation –
• Do not block fl ow of combustion or ventilation air to the water heater.
• Should overheating occur or gas supply fail to shut off, do not turn off or disconnect electrical supply
to circulator. Instead, shut off the gas supply at a location external to the appliance.
• Do not use this water heater if any part has been under water. The possible damage to a fl ooded
appliance can be extensive and present numerous safety hazards. Any appliance that has been
under water must be replaced.
4
Servicing should only be performed by a Qualifi ed Service Technician