Tools and Special Tools
Heat exchanger overheating may damage the ASH and under some conditions a safety hazard may result.
An overheat shutdown occurs when the combustion air and ventilation air fan assemblies are turned off at
the same time when in the heating modes. Always set the control panel MODE SWITCH to the VENT
position for at least 2 minutes when shutting down the ASH from the heating modes.
Contact with hot components can cause burns. Allow ASH to cool down before attempting service,
inspection, or maintenance activity.
FOR ARTIFICIAL RESPIRATION, REFER TO FM 4-25.11, FIRST AID.
Electrical high voltage cannot be seen but can kill you. Electricity is unlike most other dangerous things
you can come in contact with because it gives no warning and no symptoms to be wary of. Its effect is
immediate. It can kill you, render you unconscious, or severely burn you.
To ensure your safety and that of other maintenance personnel, always observe the following precautions:
DO NOT perform any maintenance on electrical equipment unless all power is removed.
BE CERTAIN that there is someone assisting you who can remove power immediately.
Malfunction 13. No Combustion in HEAT AUTO MODE (FLAME OUT Indicator Is On)