Laars NEOTHERM NTH Series, Installation And Operation Instructions Manual

Page: 47 / 84

Page 47
N
EO
T
HERM
Residential Boilers
®
different, depending on whether your system has a single
boiler or more than one boiler (using Lead Lag operation).
Wiring Connections -
Connect the outdoor temperature sensor.:
If your system has just one boiler –
Connect the sensor across terminals 1 and 2 on TB-7.
See Figure 30 on page 45.
If your system has more than one boiler, and is
controlled using the Lead/ Lag function –
Connect the sensor across terminals 1 and 2 on TB-7 on
the boiler which will be used as the Lead Lag Master.
Setting Up the Control Functions -
1. Enable the Warm Weather Shutdown function:
If your system has just one boiler –
How to get there: From the “Home” screen, press
“I” to go to “Info/ Install.” Choose “Advanced Setup,”
then go to “CH Configuration.” Select “Warm Weather
Shutdown.” On the line for “Warm Weather Shutdown,”
select “Immediately.”
If your system has more than one boiler, and is
controlled using the Lead/ Lag function –
How to get there: On the unit used as the Lead/ Lag
Master only - From the “Home” screen, press “I” to go
to “Info/ Install.” Choose “Advanced Setup,” then go to
“CH Configuration.” Select “Warm Weather Shutdown.”
On the line for “Warm Weather Shutdown,” select
“Immediately. ”
2. Enter the setpoint for this feature:
If your system has just one boiler –
How to get there: From the “Home” screen, press
“I” to go to “Info/ Install.” Choose “Advanced Setup,”
then go to “CH Configuration.” Select “Warm Weather
Shutdown.” Go to the line for “Warm Weather Shutdown
Setpoint”, and set the value.
If your system has more than one boiler, and is
controlled using the Lead/ Lag function –
How to get there: On the unit used as the Lead/ Lag
Master only - From the “Home” screen, press “I” to go
to “Info/ Install.” Choose “Advanced Setup,” then go to
“CH Configuration.” Select “Warm Weather Shutdown.”
On the line for “Warm Weather Shutdown Setpoint,” and
set the value.
8.M Domestic Hot Water
This boiler can be configured to supply domestic hot water
(DHW) as a stand-alone “volume” unit (DHW models)
or as a secondary function while the unit also provides
hydronic heating. The piping used to supply domestic hot
water (DHW) can be set up in several different ways. See
Section 6 for details. In this section, we will describe the
wiring and control setup for several different types of DHW
supplies.
DHW Temperature Setting -
Regardless of the type of DHW setup, the setpoint
adjustment is made the same way.
How to get there: From the “Home” screen, press “I” to
go to “Info/ Install.” Choose “Advanced Setup,” then go
to “DHW Setpoint.”
Hydronic Heating with
Domestic Hot Water (DHW) Priority -
When using the unit for hydronic heating with domestic hot
water priority, a call for heat must be supplied to the “T-T
or Interlock” terminal. Once the call is supplied, the control
starts the Boiler and System pumps and begins the ignition
process. Once in Run, the unit monitors the flame signal,
call for heat, safeties, and water temperatures modulating
as needed between 100% and 20% of rate to satisfy the
call for heat. When a DHW demand is applied during a
hydronic call for heat, the priority feature forces the boiler
to switch to the DHW demand for the priority time. The
DHW priority demand forces the control to operate to
the DHW setpoint, de-energizes the System pump and
energizes the DHW pump.
The domestic hot water temperature sensor or an aquastat
is used to monitor the DHW demand. The control uses the
DHW sensor to control the operation and modulation rate
of the unit when there is a DHW demand.
Hydronic Heating Using Local Lead-Lag/Cascading
Feature with Indirect Hot Water -
DANGER
• Water temperature over 125°F (52°C) can cause
severe burns instantly or death from scalds.
• Children, disabled and elderly are at hightest risk of
being scalded.
• Set the water temperature carefully as described
below.
• Feel the water before
bathing or showering.
• If this unit is used to
produce water that could
scald if too hot, such
as domestic hot water
use, adjust the outlet
control (limit) or use temperature limiting valves to
obtain a maximum water temperature of 125°F (52°C).