Nortek PREEVA NEOS Datasheet

MANUAL PART NO. D301315 ISS 0
INSTALLATION, COMMISSIONING AND SERVICING
MANUAL
PREEVA NEOS
GAS FIRED HEATING, VENTILATION AND COOLING UNITS
Please read this document carefully before commencing installation, commissioning and/or servicing.
Leave it with the end user/site agent to be placed in their premises technical file after installation.
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, injury or death.
All work must be carried out by appropriately qualified persons.
The manufacturer does not take any responsibility in the event of non-observance of the regulations concerning the connection of the apparatus causing a
dangerous operation possibly resulting in damage to the apparatus and/or environment in which the unit is installed.
These appliances meet the following EC directives
(EU) 2016/426: GAR
DIR 2014/30/EU:EMC
DIR 2014/35/EU:LVD
DIR 2006/42/EC:MD
ErP
2021
ErP Lot 21
Seasonal Efficiency and
NOx compliant

Contents
General Information (G)
PREEVA Neos range .........................................4
Using this manual .............................................4
Warranty ..........................................................4
Important notice to installers ............................5
Health and safety .............................................6
Uncrating / preparation.....................................7
Technical Data (TD)
Technical data ...................................................8
Dimensions.......................................................9
Installation (I)
Clearance distances ..........................................11
Indoor model location.......................................11
Outdoor model location....................................12
Minimum temperature requirements.................13
Ductwork connections ......................................14
Combustion air supply / flue arrangement.........14
Type B appliances..............................................16
Type C appliances .............................................17
Condensate drain .............................................18
Gas connection.................................................18
Electrical supply and connections ......................20
Thermostat controls ..........................................20
Wiring connections...........................................21
Commissioning and Operation (C)
Pre-start checks.................................................22
Start up ............................................................22
Air / gas ratio controls.......................................23
Gas valve adjustment........................................23
Gas conversion .................................................24
Commissioning checks .....................................24
Commissioning - handover ...............................25
Operation .........................................................27
Maintenance and Servicing (MS)
Model 25-70 component layout........................29
Model 100 component layout...........................30
Maintenance schedule ......................................31
Heat exchanger maintenance ...........................31
Replacement of gas valve..................................31
Venturi cleaning and replacement .....................32
Combustion fan cleaning and replacement .......32
Burner cleaning and replacement .....................33
Burner chamber / tube insulation check and
replacement......................................................34
Cleaning and replacement of burner probes .....36
Replacement of LC1 and LC3 safety thermostats
.........................................................................37
Replacement of ignition controller ....................38
Replacement of ignition transformer .................38
Replacement of lockout circuit board ................38
Replacement of fan relay ..................................38
Replacement of air circulation fan .....................38
Flue and combustion air....................................38
Flue condensate drainage trap ..........................38
Fan motor and fan maintenance .......................38
Unit operation ..................................................39
Fault Finding (FF)
Fault finding .....................................................40
Spare Parts (SP)
Spare parts. ......................................................42
Optional air filters .............................................43
ErP Table (ErP)
ErP table - internal units - G20 ..........................44
ErP table - internal units - G25 ..........................45
ErP table - internal units - G25.3 .......................46
ErP table - external units - G20..........................47
ErP table - external units - G25..........................48
ErP table - external units - G25.3.......................49

Page No 4 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
GPREEVA NEOS Range
General product information
PREEVA NEOS is the latest generation of
packaged gas fired heating, ventilation and
cooling units, CE and UKCA certified to
EN17082 for use in non domestic installations.
All models and sizes are available for use with
natural gas (G20, G25 or G25.3). The type of
gas, the input rate and the electrical supply
requirement is shown on the heater rating
plate. Check the rating plate to determine
if the heater is appropriate for the intended
installation.
This installation manual is shipped with the
unit. Verify that the literature is correct for
the model being installed. If the manual is
incorrect for the heater, contact the supplier
before beginning installation.
The instructions in this manual apply only to
the models listed.
Installation should be carried out by a
suitably qualified installer in accordance with
these instructions and the current rules and
regulations in force. The installer is responsible
for the safe installation of the heater.
Using this manual
The symbols for ‘Caution’ and ‘Warning’ are
used to highlight certain points throughout
this manual.
Caution is used when failure
to follow or implement the
instruction(s) can lead to
premature failure or damage to
the heater or its component parts.
Warning is used when failure
to heed or implement the
instruction(s) can lead to not only
component damage, but also to a
hazardous situation being created
where there is a risk of personal
injury.
Warranty
This equipment comes as standard with a
manufacturers two year warranty (2 years
parts, 1 year labour). The warranty is void if:
1. The installation is not in accordance with
these instructions.
2. Wiring is not in accordance with the
diagram furnished with the heater.
3. The unit is installed without proper
clearances wherever clearances are
required regardless of the material being
combustible.
4. The unit is installed without proper
ventilation and air for combustion.
5. The equipment is used in atmospheres
containing flammable vapours or
chlorinated or halogenated hydrocarbons
or any contaminant (silicon, aluminium
oxide, etc.).
6. The equipment has not been serviced
and maintained in accordance with the
information contained within these
instructions.
7. The air throughput is not adjusted within
the range specified on the rating plate.
Ignoring the warning and
caution notices, and ignoring the
advice from the manufacturer
on installation, commissioning,
servicing, or use, will jeopardise
any applicable warranty. This
could also compromise the safe
and efficient running of the
appliance itself, and thereby
constitute a hazard.
The electrical isolator should only
be used for maintenance purposes
or in an emergency. It should
not be used for closing down the
main burner, as it switches off the
fan prematurely and may damage
the heat exchanger, invalidating
the warranty.

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 5 of 52
G
including short length final connections then
we advise that installers consult with the gas
supplier or provider and satisfy themselves
what additional precautions may be necessary.
Improper installation, adjustment,
alteration, service, or maintenance
can cause property damage,
injury, or death. Read the
installation, operation, and
maintenance instructions
thoroughly before installing or
servicing this equipment.
Gas-fired appliances are not designed for
use in hazardous atmospheres containing
flammable vapours or combustible dust,
in atmospheres containing chlorinated or
halogenated hydrocarbons or in applications
with airborne silicone substances.
Any reference made to Laws, Standards,
Directives, Codes of Practice or other
recommendations governing the application
and installation of heating appliances and
which may be referred to in Brochures,
Specifications, Quotations, and Installation,
Operation and Maintenance manuals is done
so for information and guidance purposes only
and should only be considered valid at the
time of the publication.
The manufacturer cannot be held responsible
from any matters arising from the revision
to or introduction of new Laws, Standards,
Directives, Codes of Practice or other
recommendations.
External Units
Care must be taken when
installing air heaters in outdoor
locations to ensure that
unauthorised access to the
building cannot be gained via the
appliance or its ductwork system.
The unit can be installed using
full fresh air or a combination of
fresh air and recirculation air; the
unit must be provided with an
additional air intake complete with
a water separator.
Important notice to
installers
Before installation, carefully read these
instructions and follow the processes explained
by the manufacturer. These instructions are
only valid for appliances designed to operate in
Europe. If the country code and gas category
on the appliance data label does not match
the country of installation or the country codes
and gas categories as shown in this instruction
manual, it will be necessary to contact the
distributor or manufacturer to provide the
necessary information for the modification of
the appliance to the conditions of use for the
country of installation.
Installing, commissioning, testing,
programming and maintenance of these
products must only be carried out by suitably
qualified and trained technicians and in full
compliance with all applicable regulations and
current best practices.
Check if the appliance as described on the
packaging label is in accordance with the
correct type and model as specified on the
data plate and complies with your customer
order.
Check that the temperature ranges given
and those of the location match. The
appliance must be powered with a voltage
corresponding to the value shown on the
rating plate.
These units must be installed in accordance
with the rules in force and local regulations /
legislation as appropriate plus all local building
codes. Installers should satisfy themselves that
the gas pipework installation is carried out in
accordance with all current legislation, Codes
of Practice and recommendations.
Additionally it may be necessary to protect
the gas valves which form part of the heater
or burner assembly from potential pipe
contamination particularly, but not exclusively,
where copper gas pipework is used. In
instances where copper pipework is to be used
for all or part of a gas pipework installation,

Page No 6 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
GHealth and safety
Ensure that anchoring points are suitable for
the weight and loading of the product and if
required, add suitable reinforcement to the
anchoring points area.
Due consideration should be taken for
workplace safety, risk assessments and waste
disposal.
Any modification of the product may be
hazardous and the manufacturer is not liable
for any damage or injury caused by improper
use.
Do not use this appliance if any part has been
immersed in water. Immediately call a qualified
service technician to inspect the appliance
and replace any gas control that has been
immersed in water.
This appliance is not intended for use by
persons (including children) with reduced
sensory or mental capabilities or lack of
experience and knowledge, unless they
have been given supervision or instruction
concerning use of the appliance by a person
responsible for their safety. Children should
be supervised to ensure that they do not play
with the appliance.
Should overheating occur or the gas supply
fails to shut off, shut off the manual gas
valve to the appliance before shutting off the
electrical supply.
Gas-fired appliances are not designed for
use in hazardous atmospheres containing
flammable vapours or combustible dust,
in atmospheres containing chlorinated or
halogenated hydrocarbons or in appliances
with airborne silicone substances.
The manual should be kept in a safe place for
future reference.
For your safety, if you smell gas:
• Do not try to light any
appliance
• Do not touch any electrical
switch, do not use any phone
in your building
• Evacuate all personnel
• Contact your gas supplier
immediately
Do not store or use petrol or other
flammable vapours and liquids in
the vicinity of the appliance.
Improper installation, adjustment,
alteration, service or maintenance
can cause property damage, injury
or death.
Read the installation, operation
and maintenance instructions
thoroughly before installing or
servicing this equipment.
Installation, assembly,
commissioning, service and
maintenance procedures must
be carried out only by suitably
competent qualified persons.
Unauthorised modifications to
the appliance, or departure from
the manufacturer’s guidance
on intended use, or installation
contrary to the manufacturer’s
recommendations may constitute
a hazard.
Use only factory authorised parts
and spares when replacement is
required.
In case of persistent problems,
contact your distributor.

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 7 of 52
G
Uncrating / preparation
Prior to crating and shipping, this unit was test
operated and inspected in the factory and left in
full operating condition. If the unit has incurred
damage in shipment, document the damage
with the transport company and contact your
supplier.
After unpacking the appliance leave it fastened
to the wooden blocks until just before siting to
prevent damage to the base frame.
When transporting the appliance after it has
been unpacked (i.e. fork lifting, etc.) note the
restrictions and recommendation indicated
in figure 1.The base frame contains internal
support members, which act as a lifting fulcrum
point to prevent damage to the underside of the
appliance by lifting forks.
Read this booklet and become familiar with the
installation requirements of your unit. If you
do not have knowledge of local requirements,
check with the gas supplier and any other
local agencies who might have requirements
concerning this installation. Before beginning,
make preparations for necessary supplies, tools,
and manpower.
Check if the local distribution conditions of
electricity supply, type of gas and pressure of the
appliance are compatible with the data plate.
The appliance must be installed in accordance
with the current rules in force and any local or
national regulations.
The requirements of the "Local Building
Standards office", the premises "Insurance"
undertaking and the "Fire Office" must also be
observed.
If the installation includes optional vertical
louvres or downturn nozzle etc., install these
options before the heater is suspended. Follow
the instructions included in the option package.
Minimum fork
length requirement
Minimum fork
work for balance
Figure 1 - Handling Criteria

Page No 8 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
TD
Technical Data
PRN-I and PRN-E Technical Data
Model Internal (-I)
PRN025 PRN035 PRN045 PRN055 PRN070 PRN100
External (-E)
Combustion Air and Flue Type Internal B23 / B53 / C13 / C33 / C53
External Rooftop
Heat Input High Fire (HS) 1kW
32.40 41.00 51.60 64.80 86.00 119.00
Heat Input Low Fire (HS) 1kW
11.34 14.35 18.06 22.68 30.10 44.00
Heat Input High Fire (HI) 2kW
29.19 36.94 46.49 58.38 77.48 107.21
Heat Input Low Fire (HI) 2kW
10.22 12.93 16.27 20.43 27.12 37.52
Heat Output High Fire kW
26.61 33.85 42.53 53.56 70.66 99.12
Heat Output Low Fire kW
10.03 12.69 15.89 19.92 26.42 39.14
CO2 at High Fire (Throttle) G20 3%8.61 8.52 8.47
8.59 8.79 8.58
CO2 at Low Fire (Offset) G20 3%7.95 7.78 7.58
7.81 7.65 7.88
CO2 at High Fire (Throttle) G25 3%8.03 8.74 8.27
8.81 8.51 8.09
CO2 at Low Fire (Offset) G25 3%7.53 8.00 7.3 6
7.60 7.45 7.48
CO2 at High Fire (Throttle) G25.3 3%8.46 8.51 8.60
8.47 8.63 8.21
CO2 at Low Fire (Offset) G25.3 3%7.59 7.89 7.45
7.59 7.61 7.85
Gas Consumption High Fire (HS) G20 4m3/h 3.09 3.90 4.91 6.17 8.19 11.33
Gas Consumption Low Fire (HS) G20 4m3/h 1.05 1.37 1.72 2.16 2.97 4.23
Gas Consumption High Fire (HS) G25 4m3/h 3.59 4.54 5.71 7.18 9.52 13.18
Gas Consumption Low Fire (HS) G25 4m3/h 1.22 1.59 2.00 2.51 3.33 4.92
Gas Consumption High Fire (HS) G25.3 4m3/h 3.50 4.44 5.64 7. 20 9.32 12.90
Gas Consumption Low Fire (HS) G25.3 4m3/h 1.19 1.56 1.96 2.46 3.26 4.81
Gas Connection BSP 1/2" 3/4"
Flue and Combustion Air Connection
Collars (Indoor) Ø mm 100 130
Maximum Flue Length m9.5
Condensation Connection / Outlet Ø mm 22
Minimum Airflow at 15°C 5m3/h 2000 2530 3060 3980 5300 8060
Temperature Rise at Minimum Airflow K 40 40 41 40 37
Maximum Airflow at 15°C 5m3/h 3500 5080 6100 7000 10500 14000 7
Temperature Rise at Maximum Airflow K 23 21 21 20 21
Maximum external static pressure
Pa 400
Sound Level Maximum Airflow 6dBA 51.3 54.0 58.0 57.0 64.0 64.9
Sound Level Minimum Airflow 6dBA 47.2 47.2 47.0 48.3 49.6 53.2
Output cooling capacity
Maximum with DX Coil
Maximum with cooling water coil
kW
kW
19
19
28
28
30
30
30
30
51
51
63
63
Electrical Connections and
Fan Motor Rating Single Phase 1.35 kW: 230V 50HZ
1.35 kW:
230V 50HZ Not Applicable
Three Phase 3.0 kW: 380-
415V 50Hz
2.4 kW: 380-
415V 50Hz
3.3 kW: 380-
415V 50Hz
3.6 kW: 380-
415V 50Hz
5.4 kW: 380-
415V 50Hz
6.0 kW: 380-
415V 50Hz
Total Electrical Rating Single Phase 1.450 1.329 Not Applicable
Three Phase 3.060 2.480 3.390 3.670 5.530 6.19 0
Protection Grade IP IP20 Indoor / IPX4D Outdoor
Net weight without filter cabinet Kg 225 240 260 340 360 470
Net weight with filter cabinet Kg 340 355 375 490 510 640
1Refers to gross calorific value of fuel
2Refers to net calorific value of fuel
3All CO2measurements with casing panels fitted and service doors open
4Natural gas: G20 Hs 37.78 MJ/m³, G25 Hs 32.49 MJ/m³, G25.3 Hs 33.2 MJ/m³ @ 15°C and 1013.25 mbar
5Maximum temperature rise 40K. Contact manufacturer for more details on different airflow / static pressure requirements
6Measured without filter cabinet
7Maximum airflow measurement for PRN100 unit is without any optional extras i.e. filter cabinet, cooling coil, weather hood -
please contact manufacturer for details of maximum airflow / external static pressure with the options available for the unit.

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 9 of 52
TD
Dimensions
PRN-I Internal Model
(Standard Handing)
Front View Side View Rear View
Plan View
A
G
H
K
J
I
C
EFO
110
C1
O
N
D
100
B
75
P
Q1
M L 75
Q
1. Heater Section Access
2. Fan Section Access
3. Filter/Mixing Section Access
4. Gas Connection
5. Electrical Connections
6. Combustion Air Inlet
7. Flue Outlet
8. Lifting Points
1 2 3
8
76
54
Dimensions
Model PRN025-I PRN035-I PRN045-I PRN055-I PRN070-I PRN100-I
A mm 1094 1094 1094 1268 1268 1468
B mm 753 753 753 988 988 988
C mm 1684 1684 1684 1842 1842 2412
C1 mm 2704 2704 2704 3034 3034 3604
D mm 2904 2904 2904 3245 3245 3804
E mm 726 726 726 765 765 1180
F mm 187 187 187 224 224 225
G mm 110 110 110 205 205 210
H (Outlet Opening) mm 380 380 380 615 615 615
Optional Spigot for Outlet Opening mm 451 451 451 686 686 686
I mm 68 68 68 274 274 275
J mm 837 837 837 710 710 901
K mm 270 270 270 365 365 373
L mm 702 702 702 1002 1002 1202
M mm 196 196 196 133 133 133
N mm 212 212 212 229 229 229
O mm 302 302 302 502 502 502
P (Lifting centres) mm 1060 1060 1060 1234 1234 1434
Q (Lifting centres without filter cabinet) mm 1584 1584 1584 1972 1972 2106
Q1 (Lifting centres with filter cabinet) mm 2604 2604 2604 3164 3164 3298
Flue & Combustion Air Spigots mm 100 100 100 130 130 130
Please contact technical sales for dimensional data for units fitted with cooling coil or additional cabinets.
For alternative configurations please consult technical sales. Unit shown with left hand access, right hand is available but must be specified at time
of ordering as this cannot be changed once unit is built. All Dimensions have a tolerance of +/- 3mm.

Page No 10 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
TD
Dimensions
Model PRN025-E PRN035-E PRN045-E PRN055-E PRN070-E PRN100-E
A mm 1094 1094 1094 1268 1268 1468
B mm 753 753 753 988 988 988
C mm 1684 1684 1684 1842 1842 2412
C1 mm 2704 2704 2704 3034 3034 3604
D mm 2904 2904 2904 3245 3245 3804
H (Outlet Opening) mm 380 380 380 615 615 615
Optional Spigot for Outlet Opening mm 451 451 451 686 686 686
I mm 68 68 68 274 274 275
J mm 837 837 837 710 710 901
K mm 270 270 270 365 365 373
L mm 702 702 702 1002 1002 1202
M mm 196 196 196 133 133 133
N mm 212 212 212 229 229 229
O mm 302 302 302 502 502 502
P (Lifting centres) mm 1060 1060 1060 1234 1234 1434
Q (Lifting centres without filter cabinet) mm 1584 1584 1584 1972 1972 2106
Q1 (Lifting centres with filter cabinet) mm 2604 2604 2604 3164 3164 3298
R mm 649 649 649 816 816 816
Please contact technical sales for dimensional data for units fitted with cooling coil or additional cabinets.
For alternative configurations please consult technical sales. Unit shown with left hand access, right hand is available but must be specified at time
of ordering as this cannot be changed once unit is built. All Dimensions have a tolerance of +/- 3mm.
PRN-E External Model
(Standard Handing)
Rear View
A
H
K
J
I
C
O
110
C1
O
D
100
B
75 M L
75
1 2 3
5
4
69
Plan View
P
Q1
Q
1. Heater Section Access
2. Fan Section Access
3. Filter/Mixing Section Access
4. Condensate Drain Connection
5. Gas Connection
6. Electrical Connections
7. Combustion Air Inlet
8. Flue Outlet
9. Lifting Points
a. Optional Filter / Mixing Section
b. Optional Fresh Air Intake Hood
8
7
ba
b
a
Front View Side View
N

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 11 of 52
I
Installation
Internal model location
For best results, the unit should be placed with
certain rules in mind:
• Always ensure that the minimum
clearances are maintained.
• When possible, heaters should be arranged
to blow toward or along exposed wall
surfaces.
• Suspended heaters are most effective
when located as close to the working zone
as possible, but care should be exercised to
avoid directing the discharged air directly
on to room occupants.
• Partitions, columns, counters or other
obstructions should be taken into
consideration when locating the unit
heater so that a minimum quantity of
airflow will be deflected by such obstacles.
• When units are located in the centre of
the space to be heated, the air should be
discharged toward the exposed walls.
• In large areas, units should be located
to discharge air along exposed walls
with extra units provided to discharge
air in toward the centre of the area. For
optimum results heaters are best used
in conjunction with recirculating air fans
suspended at high level. Contact the
manufacturer / distributor for more details.
• At those points where infiltration of cold
air is excessive, such as at entrance doors
and shipping doors, it is desirable to locate
the unit so that it will discharge directly
toward the source of cold air, typically
from a distance of 4.5 to 6.0 metres.
Alternatively, air curtains can be installed.
Do not locate the heater where
it may be exposed to water or
where the ambient temperature
exceeds 40°C.
Suspension is not allowed when the air
handler comprises more than a heating and
ventilation section (i.e. a mixing and filter
section is included).
In cases where the installation is by means of
supporting points, make sure that the distance
between supporting points does not exceed
1.5m. In general it is recommended to support
the base where it is screwed down with
supporting points.
Ensure that the structural elements, which will
be used to suspend or support the appliance,
are adequate to carry the weight of the
appliance and its ancillary components i.e. the
flue system.
The location where the air heater is to be
installed must provide sufficient space around
the heater for servicing and clearances for
safety. Beware to allow space for the passage
of vehicles i.e. lift trucks, etc.
Ensure that the air heater is installed in a level
plane.
The heater must be fastened securely to any
base mount framework.
Clearance distances
The following table shows the minimum clearances necessary to ensure that safety from
combustibles and for servicing are maintained. In the event that the appliance is required to be
installed on the floor then a non-combustible base must be provided.
Model PRN025-I
PRN025-E
PRN035-I
PRN035-E
PRN045-I
PRN045-E
PRN055-I
PRN055-E
PRN070-I
PRN070-E
PRN100-I
PRN100-E
Min distance from wall not control side mm 150 150 150 150 150 150
Min distance from wall on control side mm 750 750 750 750 750 750
Min distance from floor to underside mm 1800 1800 2500 2500 2500 2500
Min distance from ceiling to top of unit mm 200 200 200 200 200 200

Page No 12 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
I
Always provide a minimum
clearance of 600mm at an open air
intake (inlet side)
Four-point suspension is possible from the
Ø11.0 mm holes provided in the base frame
using drop rods etc.
Ensure that suspension fixings are lock nut
secured to secure against loosening. When
suspended, the air heater should be rigid so
as to avoid placing a strain on the flue system
and connected services.
Figure 2 Detail fixation (only if unit and
framework is a one-part construction)
External model location
When installing, ensure the complete unit will
not jeopardize or compromise the integrity of
the building security.
A distance of 500mm must be maintained
between the deck on which the appliance
is installed and any air inlet provided to the
burner.
The location where the unit is to be installed
must allow sufficient space around the heater
for servicing and to allow the flue products to
escape freely.
A minimum distance of 1500mm must
be maintained on the controls side of the
appliance for access and maintenance.
When installed at ground level the entire
installation should be protected by a fence
to guard against damage and to protect the
public from possible injury.
Ensure that the structural elements which will
be used to support the appliance are adequate
to carry the weight of the appliance and its
ancillary components i.e. the ductwork system.
Ensure that the air heater is installed in a level
plain and that the surface onto which it is
installed is vibration free.
The air heater must be fastened securely to
any base mount frame work. Roof-curbs are
manufactured from galvanised mild steel and
should be fixed prior to siting the appliance.
It is necessary to provide weatherproof seals
between the appliance and the structural
elements of the building. Exposed ducting
should be insulated and covered with a
weatherproof membrane.
The duct connection to the appliance should
be made using flexible connections to reduce
noise transmission and allow for thermal
expansion of the air heating module.
When siting the appliance and unloading,
extreme care must be exercised to ensure
that the slings etc. employed do not damage
the casing. The weatherproofing will become
unsealed should any damage be sustained.
Sling spreaders must be used to provide
clearance between the appliance and the
slings. Figure 3 shows the location of spreaders
and slinging points provided for this purpose.
Use all available sling points

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 13 of 52
I
Figure 3 Lifting Sling Points
Minimum temperature requirements
If the appliance is installed in an area where extremely low external temperatures can occur,
measures will need to be taken to ensure frost protection is provided inside the burner controls
compartment. Consideration also needs to be given to the prevention of condensation forming
inside the burner controls compartment.

Page No 14 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
I
Figure 4 - Recommended Procedure and Method for the Connection of Ducting and
Transitions to the Unit Using a Typical Proprietory Flange System
Ductwork connections
The units are designed to be used in conjunction
with intake and or discharge ducting. A positive
seal should be made between any ducting
and the air heater. A flexible connection is
desirable to eliminate transmission of noise and
to take account of thermal expansion. Figure
4 illustrates a method of connection between
the appliance and the duct using a proprietary
patented connection system.
Consideration should be given to the
application of duct fittings directly connected
to the appliance. Air inlet and outlet elbows,
transitions etc. should be designed to ensure
an unrestricted and turbulent free air flow.
This requirement is to ensure that an even air
temperature is maintained when leaving the
appliance thus eliminating heat exchanger "hot-
spots" and nuisance shutdown of the burner
due to over heating.
1. Corner jointing
framework
Cut and assemble flange into
frame to suit opening
2. Cleats between
sections to be joined
Check dimensions and
position on duct spigot
4. Checking alignment
and joint worthiness
Checking location after
positioning.
6. Sectional view of
completed joint
3. Fastening through all
members
Ensuring flange is mated correctly
before fastening.
5. Applying gasket seals to
prevent air leakage
Combustion air supply / flue arrangement
A properly sized flue system is required for safe
operation of the unit. An improperly sized flue
system can cause unsafe conditions.
The unit is designed to operate safely and
efficiently with either a horizontal or vertical flue
system when installed in accordance with the
specific requirements and instructions.
The unit may be installed as a balanced flue
(type C) heater requiring both a combustion air
inlet duct and a flue pipe or as a power vented
heater (type B) where combustion air is taken
from the space where the heater is installed and
which requires only a flue pipe exhausting to
outdoors.

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 15 of 52
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All products of combustion must be flued to
outdoor atmosphere. Each heater installed
as a type B appliance must be fitted with an
individual flue pipe and the combustion air inlet
opening must be provided with a protection
grille.
Each heater installed as a type C appliance must
be fitted with an individual combustion air/flue
pipe system. Type C2 appliance, with single
duct system for supply of combustion air and
evacuation of flue gasses, are not allowed.
Flue pipe diameters and maximum (and
minimum) pipe lengths in table 1 below apply to
both horizontal and vertical systems.
Add all straight sections and equivalent lengths
for elbow. The total combined length must not
exceed the maximum flue length.
If this unit is replacing an existing unit, ensure
that the flue is sized properly for the unit being
installed and that the existing flue is in good
condition.
IMPORTANT: The flue must be
installed in accordance with
national and local regulations.
Failure to provide proper flueing
could result in death, serious injury
and/or property damage. The air
heater must be installed with a
flue to the outside of the building.
Safe operation of any power
vented gas apparatus requires a
properly operating flue system,
correct provision for combustion
air and regular maintenance and
inspection.
The appliance must be installed
with an adequate and clean air
supply for the burner that is free
from dust or other contaminants.
Prior to fitting the flue, fill the flue
condensate drainage pipework
trap with water via the flue outlet
opening.
Model PRN025-I
PRN025-E
PRN035-I
PRN035-E
PRN045-I
PRN045-E
PRN055-I
PRN055-E
PRN070-I
PRN070-E
PRN100-I
PRN100-E
Heater socket and flue diameter mm 100 130
Maximum straight length two pipes (combustion
air inlet and flue outlet pipe) with wall or roof
terminal (type C appliance)
m 9.0
Maximum straight length single pipe (flue outlet
pipe) with wall or roof terminal m 9.0
Equivalent length of 45° elbow m 0.75
Equivalent length of 90° elbow m 1.5
Minimum Flue Length m 0.5
Table 1 Flue Pipe Lengths
Flue Gas Temperature High Fire ΔT °C 172.5 159.5 159.5 161.7 174.9 146.7
Flue Gas Temperature Low Fire ΔT °C 33.6 32.7 40.4 44.3 45.3 38.4
Mass Flow Rate Flue Gases High Fire G20 kg/h 24.45 33.98 43.79 48.09 59.36 90.55
Mass Flow Rate Flue Gases High Fire G25 kg/h 29.39 30.92 47.16 46.65 71.25 109.18
Mass Flow Rate Flue Gases High Fire G25.3 kg/h 25.47 33.70 41.57 49.28 66.77 98.99
Flue Pressure at Maximum Flue Resistance Pa 7 15 15 13 14 32
Table 2 Flue Gas Properties

Page No 16 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
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Type B appliances
If the unit is to be installed as a type B
appliance, air for combustion will be taken from
within the space where the heater is installed.
Single wall seamless aluminium or stainless
steel flue pipes are required. All joints must be
sealed to prevent the products of combustion
from leaking into the building. If the flue
passes through a combustible element of the
building it must be enclosed in a sleeve of non-
combustible material and separated from the
sleeve by a minimum of 25 mm air break. The
temperature of any combustible material near
to the flue must not exceed 65°C when the
heater is in operation. The flue must be at least
150 mm away from any combustible material.
Single wall flue pipe exposed to cold air or run
through unheated areas should be insulated.
Where condensation is unavoidable, provision
must be made for the condensation to flow
freely to a point to which it can be released,
i.e. a drain or gully. The condensation drain
from the flue must be constructed from non-
corrodible material not less than 20 mm
diameter. Copper or copper based alloys must
not be used for condensation drains.
For testing, the flue pipe should include
a sealable test port. The port must be at
least 450mm away from the air heater flue
connection socket.
Follow the flue pipe manufacturers installation
instructions for making joints, including
connections to the air heater, for passing
through a building element and for support
requirements.
It is important to ensure that there is an
adequate air supply at all times for both
combustion and heating requirements.
Modern buildings involve greater use of
insulation, improved vapour barriers, and
weather proofing. These practices mean that
buildings are sealed much tighter than in the
past.
Proper combustion air supply for a power
vented Type B installation requires ventilation
of the heated space. Natural infiltration of air
may not be adequate. Use of exhaust fans
aggravates this situation. It is important to
ensure that there is adequate combustion
air supply at all times. Reliance on doors and
windows is not allowed.
Ensure that the air combustion inlet opening at
the rear side of the unit cannot be obstructed.
When these units are installed
in type B applications, air for
combustion is taken from the space
in which it is installed. Do not
restrict the combustion air intake.
Ensure that an adequate clean
air supply for combustion and
ventilation is provided within the
building in accordance with the
relevant rules and regulations in
force.
Figure 5 Approved appliances Type B
Roof B23 / B53
Wall B23 / B53
1. Combustion air inlet
with grille
2. Flue pipe outlet collar

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 17 of 52
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Type C appliances
Units used in a balanced flue application are
designed to be fitted with a combustion air
inlet duct that obtains outdoor air and a flue
pipe that exhausts flue products to outdoors.
Single wall seamless aluminium or stainless
steel flue pipes are required. All joints must be
sealed to prevent the products of combustion
from leaking into the building. If the flue
passes through a combustible element of the
building it must be enclosed by a sleeve of
non-combustible material and separated from
the sleeve by a minimum of 25 mm air break.
The temperature of any combustible material
near to the flue must not exceed 65°C when
the heater is in operation. The flue must be
at least 150 mm away from any combustible
material.
Single wall flue pipe exposed to cold air or run
through unheated areas should be insulated.
Where condensation is unavoidable, provision
must be made for the condensation to flow
freely to a point to which it can be released,
i.e. a drain or gully. The condensation drain
from the flue must be constructed from
non-corrodible material not less than 20 mm
diameter. Copper or copper based alloys must
not be used for condensation drains.
For testing, the flue pipe should include
a sealable test port. The port must be at
least 450 mm away from the air heater flue
connection socket.
Follow the flue pipe manufacturers installation
instructions for making joints, including
connections to the air heater, for passing
through a building element and for support
requirements.
C33
C53
Figure 6 Approved appliances Type C
1. Combustion air inlet
2. Flue pipe outlet collar
C13

Page No 18 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
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Condensate drain
All PREEVA Neos units are designed
with a built-in drain connection
complete with a U trap. This will
need to be filled with water (via
the flue outlet opening) during
commissioning.
Follow local regulations for the
correct disposal of condensate.
A PVC condensate discharge pipe should be
run by the installer to connect the drain from
the unit to the nearest foul drainage point.
Condensate water does not belong in a rain-
water tank!
A condensate disposal system that relies
on gravity should be satisfactory for most
installations. If a gravity system is not possible, a
condensate pump must be installed. There are a
number of commercially available pumps made
for this purpose.
If using a condensate pump, follow the pump
manufacturer’s installation recommendations.
Condensate drain pipe connections must be
glued, to prevent condensation water dripping
from the drain pipe.
The condensate water coming from the unit
heater has a pH-level of approx 4.6 and can
affect materials made from zinc and/or copper,
hence it is strongly advised against letting the
condensation water flow off through the gutter.
To ensure the condensation water does not
freeze, it is recommended to mount the drain
pipe inside the building. If there is no other
choice but mounting it outside, it is strongly
recommended to equip it with frost proof
insulation. For external units it may be necessary
to fit trace heating to the condensation pipe to
prevent freezing.
Model PRN-I 025 035 045 055 070 100
PRN-E
Condensate l/hr 0.65 0.75 0.88 1.00 1.25 1.75
Table 3 Condensate drainage flows
Gas connection
A competent and/or qualified engineer is
required to either install a new gas meter to the
service pipe or to check that the existing meter
is adequate to deal with the rate of gas supply
required. Installation pipes should be fitted in
accordance with national standards so that the
supply pressure, as stated in the technical data
section will be achieved.
It is the responsibility of the competent engineer
to ensure that other relevant standards and
codes of practice are complied with in the
country of installation. Pipes of smaller size
than the heater inlet gas connection must not
be used. The complete installation must be
tested for soundness as described in the country
of installation. Support gas piping with pipe
hangers, metal strapping, or other suitable
material.
Do not rely on the unit to support
the gas pipework installation.
Before installation, check that
the local distribution conditions,
nature of gas and pressure, and
adjustment of the appliance are
compatible.
This appliance is designed for a
maximum gas supply pressure of
50mbar. When pressure testing the
supply piping with test pressures
above 50mbar, disconnect the
heater and manual valve from the
gas supply line that is to be tested.
Cap or plug the supply line.
All sealing products must be resistant to the
action of liquefied petroleum gas or any other
chemical constituents of the gas being supplied.

Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1 Page No 19 of 52
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Install a ground joint union and manual shut-off
gas cock upstream of the unit control system.
The unit is equipped with a nipple that extends
outside the cabinet.
Check that the gas category is in accordance
with the data described on the air heater.
Ensure that a gas supply line includes a filter and
has been tested and purged in accordance with
prescribed practice prior to commissioning and
taking the air heater into service.
This appliance is equipped for a maximum gas
supply pressure of 50mbar.
Never use a flame to test for gas
soundness.
PREEVA Neos units are designed to operate on
natural gas (G20, G25 or G25.3). Check that the
gas supply, gas category and gas inlet pressure
is in accordance with the information given
on the unit data plate. To let the unit function
at maximal heat output, the gas supply pipe
MUST be correctly sized. Close to the air heater
a gas tap with coupling must be mounted for
servicing (see figure 7).
The whole of the gas service installation
including the meter must be inspected, tested
for soundness and purged in accordance with
appropriate requirements by a qualified person.
Figure 7 Gas Connection Details
Open
Closed
Table 4 Gas Supply Details
Country Gas
Category
Gas Type Nominal
Supply
Pressure
(mbar)
Maximum
Supply
Pressure
(mbar)
Minimum
Supply
Pressure
(mbar)
AT, BG, CH, CY, CZ, DK, EE,
ES, FI, GB, GR, HR, IE, IT, LT,
LV, NO, PT, RO, SE, SI, SK, TR
I2H Natural Gas (G20) 20 25 17
LU, PL, RO I2E Natural Gas (G20) 20 25 17
BE I2E(R)B Natural Gas (G20 / G25) 20 / 25 25 / 30 17 / 20
FR I2Er Natural Gas (G20 / G25) 20 / 25 25 / 30 17 / 20
DE I2ELL Natural Gas (G20 / G25) 20 / 20 25 / 30 17 / 18
NL I2EK Natural Gas (G20 / G25.3) 20 / 25 25 / 30 17 / 20

Page No 20 of 52 Reznor, PREEVA Neos, Installation Manual, EN 2021-05, D301315 Iss 1
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If the reset button requires
activating for any reason, the
cause must be determined. After
determining and correcting the
problem, restart the heater and
monitor for a period long enough
to ensure proper operation
(approximately 5 minutes).
Ensure that all cables and installers wiring are
appropriately fixed and that they do not touch
the flue or combustion collector box.
To ensure that the unit is airtight, all unused
cable couplings must be hermetically sealed.
Permanent damage can occur
to the ignition controller when
faulty/incorrect connections to the
thermostat, reset switch or burner
failure lamp are made!
Switching of wires for reset
switch and flame failure will
destroy the burner relay.
Thermostat controls
Ancillary controls are required to provide timed
heat cycles, room comfort temperature level,
frost protection, override air circulation etc.
These are not included with the appliance and
should be ordered separately.
Do not attempt to control more than one
unit from a single thermostat or control panel
unless a properly wired relay is fitted. Follow
the instructions supplied with such panels.
The location of the room thermostat or
sensor is very important. It should not be
positioned on a cold wall or cold surface.
Avoid location in draughty areas or where
it may be influenced by heat sources e.g.
the sun, process plant, etc. The thermostat
should be mounted on a vibration free surface
and mounted about 1.5 metres above floor
level. Follow the thermostat manufacturers
instructions. The thermostat must be suitable
for potential free contacts.
Electrical supply and connections
The electrical installation may
only be carried out by an
appropriately qualified person in
accordance with the current Rules
and Regulations in force.
This appliance must be earthed.
Check that the electrical specification is in
accordance with the specified data on the air
heater. All electrical connections must be made
in the heater control compartment (refer to
Figure 16). Connections must be in accordance
with the terminal markings and the wiring
diagram affixed to the unit.
The minimum external control required for
the unit is a room thermostat capable of
providing a 0-10V DC signal to the burner. It is
essential that the main input line and neutral
to terminals L and N remain live at all times
even when the unit is switched off to ensure
correct operation of the unit and to let the fan
operate independent of the heating control.
Never incorporate controls that isolate the
appliance electrically.
The supply line to the heater should include
a mains switch / isolator adjacent to the
appliance.
The minimum clearance distance between the
contacts must be more than 3 mm. Check that
the air heater is well earthed and that an earth
leakage test is carried out.
An external green indicator light is fitted on
the heater section to signify when the burner
is ON.
An external burner reset switch with red
indicator light is fitted on the unit. To add a
remote reset button, make connections to the
terminals in the electric box as indicated on
the wiring diagram.