McDonnell & Miller MM 286 Series 1575 Low Water Cut-Off - Manual (Page 9)

Adjusting Burner Delay (DOB)
The boiler should begin to fill with wa t e r.
N OT E : If water does not start filling the boiler,
immediately turn off the the boiler and make
the necessary corrections.
For Automatic Reset Models:
When the water level reaches the level of the
middle probe, the burner circuit should be acti-
vated and the Red LED should turn off. (Pump
#2 should turn off with Dual Pump Applications).
When the water level rises to the level of the top
p r o b e, the pump relay will be de-activa t e d .
Depending on the application, this will either turn
off the pump or close a va l ve.
The number of seconds that water must be off the
s h o rtest probe before the bu rner will turn off is
a d j u s t a ble from 0 to 60 seconds. The unit is fa c t o ry
set at 0 seconds. To adjust, turn the adjusting screw
c l o ckwise using a small flatblade screw d ri ver to the
d e l ay time desired.
Fo l l ow the bl ow down procedure found on page 11
to ve rify opera t i o n .
I N S TA L L ATION COMPLETE
If the time delay on the primary control set is too long,
the manual reset secondary LWCO may turn off the
boiler before the primary control turns off the boiler.
If this occurs, shorten the time delay by turning the
adjustment screw counter- cl o ckwise from the new setting.
NOTE
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