62
Rev. 05/2020
CHAPTER 19
EXTERIOR CLADDING AND INSULATION
Outer Front Door of the HEATMOR™
Principles of the Outer Front Door
The outer door of the furnace is an exterior door, which is
insulated to retain the heat that radiates from the firebox
door and water jacket surface. The door provides a
lockable, protective surface to prevent any hot surface from
being exposed.
Operation of the Outer Front Door
The outer door is hinged and opens to the right of the
furnace. As the door opens, it releases the Automatic Fan Switch,
which allows air to enter the air box reducing the risk of a flashback.
A keyed lock is installed on the left side of the door providing an
easy way to ensure the door cannot be opened causing untrained
users to be injured.
Maintenance / Result
Keep the door free from any obstruction and ensure that the inner
seal of the door seals against the doorframe. This will keep cold air
from entering the heated air cavity, which provides the air box and
firebox with air.
Removal and Replacement
To remove the outer door, the lock handle must be unlocked and
opened. Pick up the old door from the hinges and place and secure
the new door into position. Test the door to ensure a tight seal to the
doorframe of the furnace.
Roof of the HEATMOR™
Principle of the Roof
The roof of the furnace is one solid piece of roofing steel
creased in the center. This provides a dry covering to
protect the insulation of the furnace.
Maintenance / Result
Inspect the roof of the furnace once a year to verify that
none of the roof screws have broken. A large number of
broken roof screws can allow damage to the furnace roof.
Ensure the lift hook and chimney are sealed so no water
can enter into the roof insulation.
ABSOLUTELY NO FIRE IN THE FIREBOX WHEN PERFORMING THIS REPAIR. DO NOT
PERFORM THIS REPAIR WHEN UNIT HTF TEMPERATURE IS UNSAFE. ALWAYS WEAR
PROPER PERSONAL PROTECTIVE EQUIPMENT.
Roof
Outer Front and Back Door
Lockable Door
