Install Instructions

Page 15
NEOTHERM Residential Boilers
NeoTherm with a pump MUST be piped in a primary-
secondary fashion (using either piping or a hydraulic
separator) such that the pump that is mounted on the boiler
ONLY serves the boiler.
When the pump is supplied by Laars, the NeoTherm boiler
must be located within 15 feet (4.6m) of the supply and return
header (or the hydraulic separator). Pumps supplied by Laars
are sized for a maximum of 30 feet (9.1m) of connection size
piping and the headloss of the boiler only. (See Table 14.)
If longer pipe lengths are required, the pump should be sized
for the boiler and for the piping it will serve, and should be
supplied to the job separately. Even with pumps supplied by
others, Laars strongly recommends primary-secondary piping.
6.2NTHColdWaterMake-Up
1. Connect the cold water supply to the inlet connection of
an automatic ll valve.
2. Install a suitable back ow preventer between the
automatic ll valve and the cold water supply.
3. Install shut off valves where required.
The boiler piping system of a hot water heating boiler
connected to heating coils located in air handling appliances
where they may be exposed to refrigerated air circulation
must be equipped with ow control valves or other automatic
means to prevent gravity circulation of the boiler water during
the cooling cycle.
A boiler installed above radiation level, or as required by the
authority having jurisdiction, must be provided with a low
water cutoff device either as a part of the boiler or at the time
of boiler installation.
NTH PIPESIZE,
SIZE INCHES
80 1
105 1
150 1
210 1¼
Table15. -WaterConnection
Pipe Sizes
Section 6
WATER CONNECTIONS -
NTH BOILER
6.1 NTHSystemPiping-  
 HotSupplyConnections
NOTE: This appliance must be installed in a closed
pressure system with a minimum of 12 psi (82.7kPa)
static pressure at the boiler.
Hot water piping should be supported by suitable hangers or
oor stands. Do not support piping with this appliance. Due
to expansion and contraction of copper pipe, consideration
should be given to the type of hangers used. Rigid hangers
may transmit noise through the system resulting from the
piping sliding in the hangers. It is recommended that padding
be used when rigid hangers are installed. Maintain 1” (2.5cm)
clearance to combustibles for hot water pipes.
Pipe the discharge of the relief valve (full size) to a drain or
in a manner to prevent injury in the event of pressure relief.
Install an air purger, an air vent, a diaphragm-type expansion
tank, and a hydronic ow check in the system supply loop.
Minimum ll pressure must be 12psig (82.7kPa). Install
shutoff valves where required by code.
NeoTherm’s efciency is higher with lower return
water temperatures. Therefore, to get the most of low return
temperature with multiple boilers, pipe as shown in Figure 9
through Figure 15.
NeoTherm NTV models 150-500 can be ordered with or
without a pump included.
NeoTherm NTH models 80-500 can also be ordered with or
without a pump included.