09/01/2020
12
BI601
Manual Reset Hi-Limit
At the top of the vessel there will be either two or three surface mount hi-limits preset at 205° F. There is
no light indicator associated with these safety hi-limits. Also these 205° F safety limits break the L2
current carrying 240/208-volt wire going to the elements. Reset involves locating a small shiny lever or
metal tab protruding on the side of the black safety limit base. This small tab is pressed inward
approximately 1/8” to snap in the contacts.
CAUTION
The wires and screws have 240/208-volt potential and can be dangerous. Turn off circuit
breakers before investigating or attempting to reset the 205° F safety limits.
Internal Fuse
The fuse on the controller board protects the transformer secondary, external items connected to R, and
the circuit board itself. Replace with 2-amp, fast blow fuse or equivalent.
System Pressure
The side press/temperature gauge should be at approximately 10 to 14 PSI at room temperature water and
should not rise more than approximately 4 PSI at the operating or hot water temperature. If the pressure
change is more than approximately 4 PSI, the expansion tank is too small or there is a problem with the
expansion tank piping, expansion tank itself.
Cold slab, outdoor reset and temperature sensing prevent full boiler on
– by adding a
temporary
jumper between the lower W screw terminal and the upper left E tab, all temperature sensing functions
are bypassed and the control board will step in all the stages.
CAUTION
This jumper shall not be a permanent function, jumper needs to be removed after slab is
approaching normal temperature.
Standby Switchover, SOT Timer
This plug-in option device allows a selection from 40 to 80 minute thermostat operating time for
automatic switchover to standby boiler. Order part number SOT-1.
WARNING – HIGH VOLTAGE
MUST SHUT OFF HIGH VOLTAGE BEFORE
ATTEMPTING TO RESET.