1611UDSBD-3GBEN, Pag. 32/36
23. Limit
Controls
Fan Delay
Control
If a limit control needs
replacing, use only the
f a c t o r y a u t h o r i z e d
replacement part for
the size of heater. For
approximate limit loca-
tins, see fi gure 11a.
Figure 21 : LC1
Figure 22 : LC3
Warning :
Never bypass the limit
controls, hazardous
conditions could result.
a) Limit controls
All units are equipped with temperature activated limit controls. The controls are
factory set and non-adjustable. If either setpoint is reached, the corresponding
limit control will interrupt the electric power to the gas valve. These safety devices
provide protection in the case of motor failure or lack of airfl ow due to restrictions.
(For locations, see fi gure 11a.)
Figure 23 : Location LC1/LC3
Figure 24 : Fan delay control (KFC)
24. Flue and
combustion
air piping
Check the complete system at least once a year. Inspection should include all joints,
seams, concentric adapters and the fl ue terminal cap. Replace any defective or
heavily corroded parts.
b) Fan delay control
All units are equipped
with a fan delay control.
T h i s c o n t r o l w i l l
active/disactivate the
centrifugal fan as per
non-adjustable factory
set times. For comfort
reasons, the centrifugal
fan starts running a
period later than the
burner has been ignited.
To avoid switching of
the limit controls, the fan
still runs some time after
the gas valve has been
closed to cool down the
heat exchanger.
