LAARS Mascot LX MLXC 175 MBH - Install and Operating Manual - Manual (Page 39)

Mascot LX Boilers and Water Heaters Page 35
Laars SIT Parameters
Page 2
P49 CH Priority time over DHW 0 min SWITCHOVTCH
P50 DHW Priority time over CH 55 min * displayed as seconds SWITCHOVTHW
P51 DHW tank setpoint 180 ° F HWTNKSETP
P52 Stop DHW tank demand offset 0 ° F HWDEMSTOP
P53 Start DHW tank demand offset 6 ° F HWDEMSTART
P54 Block DHW demand (combi) offset 12 ° F HWREGBLO
P55 Unblock DHW demand (combi) offset 20 ° F HWREGHYS
P56 Minimum user setting DHW set point 60 ° F CMINHW
P57 Maximum user setting DHW set point 140 ° F CMAXHW
P58 Frost protection s tart pump temperature 45 ° F FROSTPMP
P59 Frost protection start burner temperature 37 ° F FROSTBURN
P60 Frost protection stop burner hysteresis 5 ° F FROSTHYS
P61 Low outdoor air temperature for heat curve 25 ° F HC1AX
P62 High setpoint for heat curve 180 ° F HC1AY
P63 High outdoor air temperature for heat curve 70 ° F HC1BX
P64 Low setpoint for heat curve 120 ° F HC1BY
P65 Outside temperature disabling CH demand 90 ° F HC1OUTLIM
P66 Outside temperature disabling CH hysteeresis 5 ° F HC1OUTHYS
P70 Minimum user setting CH set point 32 ° F CMINCH
P71 Maximum user setting CH set point 190 ° F CMAXCH
P72 Block offset CH demand 10 ° F CH1BLO
P73 Block hysteresis CH demand 20 ° F CH1HYS
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8.5 SERVICE Mode
The Mascot LX Series of appliances has been
designed with a SERVICE Mode of operation
intended for servicing and troubleshooting of the
unit by a Mascot LX trained service technican.
‘SERVICE' Mode can be activated by pressing
and holding the 'Select/OK' button and ‘Up Arrow’
simultaneously for five seconds. With an active call
for heat, the boiler will light and run at 100% of firing
rate. The boilers input can be adjusted in 20% rate
increments by pressing the ‘Up’ or ‘Down’ Arrows. You
can also toggle between Maximum Rate and Minimum
Rate by pressing the 'Select/OK' button. To exit
SERVICE Mode depress and hold the 'Select/OK' button
for five seconds.
Table 16. Installer Parameters (part 2)
8.6 Modulation Control
The control uses a PID algorithm to adjust the firing
rate of the boiler as the control point is approached.
The goal of the control is to operate at a minimum
firing rate to match the load on the appliance.
8.7 Pump Control
The boiler pump is active anytime there is a call for
heat applied to the control. When there is a central
heat call the system pump relay is active. If there
is a DHW call while the central heat call is active
the system pump turns off. This happens because of
domestic hot water priority, which forces the control
to satisfy the domestic water demand prior to the
hydronic demand. When the last heat demand is
satisfied the boiler pump enters an overrun time.
NOTE: There must be an active call for heat given
to the appliance for Service Mode to allow the
boiler to start. When the Service Mode is exited,
the boiler will continue to run until the call is either
satisfied or removed.
will stop.
The parameter value will return to the previous
setting if you press the Cancel button.
Otherwise, Exit INSTALLER Mode by pressing
and holding 'Select/OK' for 3 seconds.