National Comfort Products CPG41838-U, Instruction Manual

Page: 39 / 80

39
Gas Furnace
External Draining
The condensing furnace external drainage is critical to the furnaces continued operation.
Regardless of the desired drainage configuration, all tubing must be secured with the routing
clamps provided using the predrilled mounting holes. Downstream of the waterless trap will
be a field connected 5/8" vinyl tube that must be directed into an air break before any other
drainage is tied into the unit. This includes the condensate drain for the cooling section.
IMPORTANT: The furnace drain must be in a conditioned space and in some cases
additional means for heating the drain line (such as heat tape) will be necessary to
avoid freezing.
Clear tubing to fit into field
installed drain line.
There must be an air break
surrounding the clear
tubing.
Freeze Safety Thermostat (Certain Models)
The freeze safety thermostat is used to protect the furnace condensate from freezing. The
thermostat is wired into the DSI control board in a manner that when it closes it will energize
the heating section and allow it to heat up the area where all drainage parts are located.