LAARS NeoTherm NTV1000 - Install and Operating Manual User Manual
Page 86
LAARS Heating Systems
Page 82
fig. 113 – lead/lag master Screen
4. Press the Configure button. The display will
present the Lead/Lag Master Configuration
Screen (Fig. 114).
Fig. 114 – Lead/Lag Master Configuration
Entries on this screen allow you to set the CH
setpoint and DHW setpoint.
5. Press the button for Advanced Settings. This
leads to a “ring” of related screens, and you
can scroll through the list by pressing one of
the left- or right-arrow symbols. Press the
left-arrow or right-arrow until you see the
Domestic Hot Water screen (Fig. 115).
fig. 115 – Domestic Hot Water
An entry on this screen allows you to give
priority to the DHW function.
Setup type 2 –
As a second option, a system can be set up so that
only one or two boilers respond to a demand for
domestic hot water. This allows the other boilers
in the system to continue to service the demand for
central heating. This system is more flexible, but the
setup is a bit more complicated:
• All of the boilers are tied together in the
normal way, using the Modbus connections.
• The DHW demand must switch over a whole
boiler (including both burners), not just a
single burner. Both burners in a boiler should
always use the same setpoint.
• The plumbing must be set up so that, during
DHW demand, each boiler used for DHW
is pumped by the DHW pump, and the
boiler pump is turned off. This will keep the
temperature zones separate.
• Each of the boilers that will handle DHW is
wired with an input from the aquastat used to
indicate DHW demand. The aquastat demand
should be jumpered from the Primary control
in each boiler (terminals 5 and 6 on TB6 to
terminals 7 and 8 on TB6).
• The LL CH setpoint used by all of the boilers
is set in the normal way, working from the
Lead/Lag section of the software.
• On each of the boilers used for DHW, priority
is given to the DHW function. Because this
affects individual boilers, rather than the
whole system, this part of the setup is done
from outside the Lead/Lag system.