Zehnder Rittling RW Series Installation and operating instructions

Installation, Operations and Maintenance
Rittling
Cabinet Unit Heater
Hydronic Heating Radiant Ceiling Systems

With Zehnder, you will find the perfect
climate for any space. www.zehnder-systems.com
IMPROVED
QUALITY OF LIFE
Zehnder decorative radiators
Comfortable indoor ventilation
Heating and cooling ceiling systems
Clean air solutions

IMPORTANT: Submittal
documentation, specific to each
project, supersedes the general
guidelines contained within this
manual.
Models and arrangements 2
Ratings 4
Dimensions and data 6
General information 13
Receiving 13
Safety considerations 14
Unpacking and preparation 15
Handling and installation 16
Hot water connections 17
Ductwork connections 18
Electrical connections 19
Wiring diagram 20
Start-up 22
Air system balancing 23
Heating system 23
Water system balancing 24
Water treatment 24
Controls operation 25
Exposed unit touch-up 25
Normal operation/maintenance 26
Replacement parts 28
Equipment start-up checklist 28
Warranty 30
1

Models and airflow arrangements
Wall models
RW-260
RWI-290
RW-280
RWI-310
RW-270
RWI-300
RW: Wall
RW-260 shown
RW-270 and RW-280 available
RWI: Wall, inverted flow
RWI-290 shown
RWI-300 and RWI-310 available
RRW-320
RRW: Wall, partially recessed
RRW-320 shown
RRWI-330
RRWI: Wall, partially recessed, inverted flow
RRWI-330 shown
RFRW-340
RFRW: Wall, fully recessed
RFRW-340 shown
RFRWI-350
RFRWI: Wall, fully recessed, inverted flow
RFRWI-350 shown
MODELS AND ARRANGEMENTS
2

Models and airflow arrangements
Floor models Ceiling models
RC-360
RC-370
RC-380
RFRC-410
RC-390
RFRC-420
RC-400
RFRC-430
RRC-400
RF-200 RF-220
RF: Floor
RF-200 shown, RF-220 available RC: Ceiling
RC-360 shown
RC-370, RC-380, RC-390 and
RC-400 available
RFI-240 RFI-250
RFI: Floor, inverted flow
RFI-240 shown, RFI-250 available
RS-200
RS: Floor, sloped
RS-200 shown
RRC: Ceiling, partially recessed
RRC-440 shown
RFRC: Ceiling, fully recessed
RFRC-420 shown
RSI-240
RSI: Floor, sloped, inverted flow
RSI-240 shown
3

Standard ratings and specifications
Table A
Specifications 02 03 04 06 08 10 12
Steam capacity MBH 18.7 25.5 34.8 51.0 62.8 73.4 90.7
EDR 76 104 144 212 260 304 376
Hot water capacity
(1 row coil)
MBH 16.2 22.4 30.7 45.5 54.8 64.5 80.1
GPM 1.7 2.3 3.2 4.8 5.7 6.7 8.4
WPD 0.2 0.4 0.8 2.2 0.5 0.7 1.2
Hot water capacity
(2 row coil)
MBH 25.0 34.3 47.2 69.5 86.6 101.2 125.8
GPM 2.6 3.6 4.9 7.3 9.0 10.5 13.1
WPD 0.8 1.7 3.6 9.3 2.2 3.3 5.6
CFM: standard
High 220 300 420 620 810 940 1180
Medium 150 200 310 450 600 720 875
Low 125 140 220 350 440 480 660
CFM: high static
(@ 0.2" ESP)
High 250 345 490 640 920 1020 1150
Medium 210 290 425 550 780 870 980
Low 160 230 320 420 590 660 750
Coil
FPI 12 12 12 12 12 12 12
Face area, ft2 1.25 1.67 2.08 2.92 3.33 3.89 4.58
Coil connections 1/2" Cu 1/2" Cu 1/2" Cu 1/2" Cu 1/2" Cu 1/2" Cu 1/2" Cu
Blower
Quantity 11221, 2 4 4
Diameter 5.7" 5.7" 5.7" 5.7" 5.7" 5.7" 5.7"
Width 7.5" 10.4" 7.5" 10.4" 7.5", 10.4" 7.5" 10.4"
Filter
Number 1111111
Length, in. 22 28 34 46 52 60 70
Width, in. - standard 9.75 9.75 9.75 9.75 9.75 9.75 9.75
Width, in. - floor with inlet grille 7.25 7.25 7.25 7.25 7.25 7.25 7.25
Rating Merv 4 Merv 4 Merv 4 Merv 4 Merv 4 Merv 4 Merv 4
Thickness, in. 1111111
Cabinet size
Length, in. 38.2 44.2 50.2 62.2 68.2 76.2 86.2
Width, in. 10 10 10 10 10 10 10
Height, in. - wall/ceiling 24 24 24 24 24 24 24
Height, in. - flat top floor 26.5 26.5 26.5 26.5 26.5 26.5 26.5
Height, in. - slope top floor 29.25 29.25 29.25 29.25 29.25 29.25 29.25
Shipping weight, lbs. 85 100 115 140 155 170 195
Notes
Airflows for floor mounted units with 1-row coil. Please check with factory
for adjusted outputs on other models
Heating capacity based on inlet air 60 ˚F DB, 200˚F entering water or 2 psig
steam, 180˚F leaving water, standard motor at high fan speed
Pressure drop (PD) shown in feet of water
Overall length for fully and partially recessed units is length +3", adding
in the trim kit. Wall rough-in hole dimension to be length +1/2" by 24-1/2"
minimum. Maximum opening to be length by +2" by 26".
STANDARD RATINGS
4

Table B
Motor Type 02 03 04 06 08 10 12
HP
PSC Standard 1/30 1/30 1/25 1/15 1/30, 1/15 (2) 1/15 (2) 1/15
High-Static 1/12 1/12 1/10 1/7 1/12, 1/7 (2) 1/7 (2) 1/7
ECM
Standard 1/4 1/4 1/4 1/4 (2) 1/4 (2) 1/4 (2) 1/4
High-Static 1/4 1/4 1/4 1/4 (2) 1/4 (2) 1/4 (2) 1/4
RPM High
PSC Standard 895 995 900 1150 1150 1250 1200
High-Static 1505 1510 1550 1550 1550 1550 1550
ECM
Standard 1050 1025 920 1120 1150 1250 1200
High-Static 1550 1550 1550 1550 1550 1550 1550
RPM Medium
PSC Standard 833 754 720 900 900 860 950
High-Static 1390 1320 1320 1320 1320 1320 1320
ECM
Standard 875 700 720 870 900 850 950
High-Static 1320 1320 1320 1320 1320 1320 1320
RPM Low
PSC Standard 620 575 530 710 625 650 550
High-Static 1300 1200 1000 1000 1000 1000 1000
ECM
Standard 750 600 530 685 625 640 550
High-Static 1000 1000 1000 1000 1000 1000 1000
Motor FLA 120V PSC Standard 0.60 0.60 0.68 1.13 1.73 2.26 2.26
High-Static 1.05 1.05 1.2 1.7 2.8 3.4 3.4
ECM Standard 0.92 0.84 1.12 1.70 2.85 3.04 3.58
Power Input:
Watts 120V
PSC
Standard 57 61 75 130 200 240 250
High-Static 117 120 130 180 325 368 368
ECM Standard 38 38 45 80 125 147 157
Electrical data
Notes:
Maximum circuit ampacity (MCA) =
1.25 x (FLA motor 1 + FLA motor 2 + FLA electric heat)
Maximum overcurrent protection (MOP) =
(2.25 x FLA motor 1) + FLA motor 2 + FLA electric heat
If the calculated MOP is within 10% of the next smaller available fuse size,
that fuse size shall be used. If not, the next larger fuse size above the
calulated MOP must be used.
If the selected MOP is smaller than the MCA, the selected MOP must be
increased to the next larger available fuse size above the MCA.
If the MOP is less than 15, it shall be rounded up to 15 amps. This is the
minimum fuse or circuit breaker permitted by code.
EC motor nameplate amperage indicates the motor hardware peak
amperage while the motor full load amperage (FLA) is limited by the motor’s
factory programmed operating range, programmed specifically for each unit
size. The programmed operating range is generally only a portion of the
motor hardware full potential resulting in the motor FLA being lower than
the nameplate FLA. Motor FLA will be reflected on the Cabinet Unit Heater
serial tag and should be used when sizing building electrical requirements.
ELECTRICAL DATA
5

6
Revised June 1, 2018. Zehnder Rittling periodically makes changes to the design and/or specifications of its products. As a result, the design and specifications of each product at the time of order may be different than as
described herein. Please contact Zehnder Rittling's Sales Support staff at 716-827-6510 for specific information on current design and specifications. Designs, specifications and other information contained herein are not express
warranties, which are only as expressly set forth by Zehnder Rittling in its terms and conditions of sale. The latest version of this document is available at www.zehnder-rittling.com.
Rittling Cabinet Unit Heater
Submittal Data
Zehnder Rittling · 100 Rittling Blvd. · Buffalo, NY USA 14220
T 716-827-6510 · F 716-218-2805 · [e-mail] · www.zehnder-rittling.com
© Zehnder Rittling June 2018, English, subject to change without notice
8 1/8"
2"
T
P
N
R
12 13/16"
7 1/8"
M
K
7 1/8"
2"
16 1/8"
J
L
20 13/16"
6 1/2"
16"
2, 3 & 4 row hot
water supply
water return
1 row hot
and 1 row
water return
Side view: Model RFI
steam supply
steam return
and 1 row
water supply
2, 3 & 4 row hot
1 row hot
Filter positions
RF-200
shown
RF-220
shown
(top outlet)
access section
Top view
Fan speed
section
Piping access
Outlet opening centered
6"
D
10"
1 row hot
water supply
and 1 row
steam supply
steam return
and 1 row
2, 3 & 4 row hot
water return
Side view: Model RF
position
Filter
1 row hot
water return
2, 3 & 4 row hot
water supply
Front view
(Front outlet)
A
6"
3 1/2"
3"
26 1/2"
Models RF and RFI
Dimensions and data
Dimensional data
Unit size AB CD
Std. 6" Ext
02 38-3/16 44-3/16 22-3/16 23-5/8 20
03 44-3/16 50-3/16 28-3/16 29-5/8 26
04 50-3/16 56-3/16 34-3/16 35-5/8 32
06 62-3/16 68-3/16 46-3/16 47-5/8 44
08 68-3/16 74-3/16 52-3/16 53-5/8 50
10 76-3/16 82-3/16 60-3/16 61-5/8 58
12 86-3/16 92-3/16 70-3/16 71-5/8 68
Dimensional data
Coil J K L M NP R T
2 Row 18-1/4 4-7/16 19-1/16 5-3/16 9-7/8 5-3/16 10-11/16 4-7/16
3 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
4 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
* Add 6" per extended end selection. See chart for details.
mounting slot
3/8" wd. x 1" lg.
(4 places)
Note: Inlet grille optional
Electrical
end pocket
Front view
(less front panel)
* 8" B * 8"
C
8 1/8"
2"
T
P
N
R
12 13/16"
7 1/8"
M
K
7 1/8"
2"
16 1/8"
J
L
20 13/16"
6 1/2"
16"
2, 3 & 4 row hot
water supply
water return
1 row hot
and 1 row
water return
Side view: Model RFI
steam supply
steam return
and 1 row
water supply
2, 3 & 4 row hot
1 row hot
Filter positions
RF-200
shown
RF-220
shown
(top outlet)
access section
Top view
Fan speed
section
Piping access
Outlet opening centered
6"
D
10"
1 row hot
water supply
and 1 row
steam supply
steam return
and 1 row
2, 3 & 4 row hot
water return
Side view: Model RF
position
Filter
1 row hot
water return
2, 3 & 4 row hot
water supply
Front view
(Front outlet)
A
6"
3 1/2"
3"
26 1/2"
Models RF and RFI
Dimensions and data
Dimensional data
Unit size AB CD
Std. 6" Ext
02 38-3/16 44-3/16 22-3/16 23-5/8 20
03 44-3/16 50-3/16 28-3/16 29-5/8 26
04 50-3/16 56-3/16 34-3/16 35-5/8 32
06 62-3/16 68-3/16 46-3/16 47-5/8 44
08 68-3/16 74-3/16 52-3/16 53-5/8 50
10 76-3/16 82-3/16 60-3/16 61-5/8 58
12 86-3/16 92-3/16 70-3/16 71-5/8 68
Dimensional data
Coil J K L M NP R T
2 Row 18-1/4 4-7/16 19-1/16 5-3/16 9-7/8 5-3/16 10-11/16 4-7/16
3 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
4 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
* Add 6" per extended end selection. See chart for details.
mounting slot
3/8" wd. x 1" lg.
(4 places)
Note: Inlet grille optional
Electrical
end pocket
Front view
(less front panel)
* 8" B * 8"
C
Dimensions and data Models RF and RFI
Dimensional data
Unit size AB C D
Std. 6" Ext. 6" Ext. x2
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68
Notes:

1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes


Inlet grill optional


Unit shown with left hand piping connections and right hand electrical connections as standard


Right hand piping connections with left hand electrical connections available as an option


Piping hand determined when facing the air outlet

All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder at its base office
 See www.zehnder-rittling.com for any recent updates or changes
Dimensions and data
DIMENSIONS AND DATA
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
Inlet grille optional
Unit shown with left hand piping connections and right hand electrical connections as standard
Right hand piping connections with left hand electrical connections available as an option
Piping hand determined when facing the air outlet
All listed dimensions are approximate and are subject to change without notice
Modifications to the product specifications must be accepted by Zehnder Rittling at its base office
See www.zehnder-rittling.com for any recent updates or changes
Dimensional data
Unit size AB C D
Std. 6" Ext. 6" Ext. x2
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68
Models RF and RFI

Revised June 1, 2018. Zehnder Rittling periodically makes changes to the design and/or specifications of its products. As a result, the design and specifications of each product at the time of order may be different than as
described herein. Please contact Zehnder Rittling's Sales Support staff at 716-827-6510 for specific information on current design and specifications. Designs, specifications and other information contained herein are not express
warranties, which are only as expressly set forth by Zehnder Rittling in its terms and conditions of sale. The latest version of this document is available at www.zehnder-rittling.com.
Rittling Cabinet Unit Heater
Submittal Data
Zehnder Rittling · 100 Rittling Blvd. · Buffalo, NY USA 14220
T 716-827-6510 · F 716-218-2805 · [e-mail] · www.zehnder-rittling.com
© Zehnder Rittling June 2018, English, subject to change without notice
M
K
7 1/8"
2"
16 1/8"
J
L
20 13/16"
8 1/8"
2"
T
P
N
R
12 13/16"
7 1/8"
6 1/2"
16"
1 row hot
water supply
steam supply
and 1 row
steam return
and 1 row
2, 3 & 4 row hot
water return
Side view: Model RS
position
Filter
1 row hot
water return
2, 3 & 4 row hot
water supply
Front view
(Front outlet)
3 1/2"
29 1/4"
A
Models RS and RSI
Dimensions and data
Dimensional data
Coil J K L M NP R T
2 Row 18-1/4 4-7/16 19-1/16 5-3/16 9-7/8 5-3/16 10-11/16 4-7/16
3 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
4 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
Dimensional data
Unit size AB CD
Std. 6" Ext
02 38-3/16 44-3/16 22-3/16 23-5/8 20
03 44-3/16 50-3/16 28-3/16 29-5/8 26
04 50-3/16 56-3/16 34-3/16 35-5/8 32
06 62-3/16 68-3/16 46-3/16 47-5/8 44
08 68-3/16 74-3/16 52-3/16 53-5/8 50
10 76-3/16 82-3/16 60-3/16 61-5/8 58
12 86-3/16 92-3/16 70-3/16 71-5/8 68
* Add 6" per extended end selection. See chart for details.
water return
2, 3 & 4 row hot
1 row hot
steam supply
water supply
2, 3 & 4 row hot
Side view: Model RSI
steam return
and 1 row
water supply
1 row hot
water return
and 1 row
Filter position
(top outlet)
access section
Top view
Fan speed
section
Piping access
Outlet opening centered
6"
D
10"
mounting slot
3/8" wd. x 1" lg.
(4 places)
Note: Inlet grille optional
Electrical
end pocket
Front view
(less front panel)
* 8" B * 8"
C
M
K
7 1/8"
2"
16 1/8"
J
L
20 13/16"
8 1/8"
2"
T
P
N
R
12 13/16"
7 1/8"
6 1/2"
16"
1 row hot
water supply
steam supply
and 1 row
steam return
and 1 row
2, 3 & 4 row hot
water return
Side view: Model RS
position
Filter
1 row hot
water return
2, 3 & 4 row hot
water supply
Front view
(Front outlet)
3 1/2"
29 1/4"
A
Models RS and RSI
Dimensions and data
Dimensional data
Coil J K L M NP R T
2 Row 18-1/4 4-7/16 19-1/16 5-3/16 9-7/8 5-3/16 10-11/16 4-7/16
3 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
4 Row 19-1/16 3-1/16 20-3/8 4-13/16 8-9/16 4-13/16 9-7/8 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
Dimensional data
Unit size AB CD
Std. 6" Ext
02 38-3/16 44-3/16 22-3/16 23-5/8 20
03 44-3/16 50-3/16 28-3/16 29-5/8 26
04 50-3/16 56-3/16 34-3/16 35-5/8 32
06 62-3/16 68-3/16 46-3/16 47-5/8 44
08 68-3/16 74-3/16 52-3/16 53-5/8 50
10 76-3/16 82-3/16 60-3/16 61-5/8 58
12 86-3/16 92-3/16 70-3/16 71-5/8 68
* Add 6" per extended end selection. See chart for details.
water return
2, 3 & 4 row hot
1 row hot
steam supply
water supply
2, 3 & 4 row hot
Side view: Model RSI
steam return
and 1 row
water supply
1 row hot
water return
and 1 row
Filter position
(top outlet)
access section
Top view
Fan speed
section
Piping access
Outlet opening centered
6"
D
10"
mounting slot
3/8" wd. x 1" lg.
(4 places)
Note: Inlet grille optional
Electrical
end pocket
Front view
(less front panel)
* 8" B * 8"
C
Dimensions and data Models RS and RSI
Dimensional data
Unit size AB C D
Std. 6" Ext. 6" Ext. x2
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
 Inlet grill optional
 Unit shown with left hand piping connections and right hand electrical connections as standard
 Right hand piping connections with left hand electrical connections available as an option
 Piping hand determined when facing the air outlet
 All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder at its base office
 See www.zehnder-rittling.com for any recent updates or changes
RS-200
shown
Dimensions and data
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
 Inlet grille optional
 Unit shown with left hand piping connections and right hand electrical connections as standard
 Right hand piping connections with left hand electrical connections available as an option
 Piping hand determined when facing the air outlet
 All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder Rittling at its base office
 See www.zehnder-rittling.com for any recent updates or changes
Dimensional data
Unit size AB C D
Std. 6" Ext. 6" Ext. x2
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68
7
Models RS and RSI
RS-200
shown

Revised June 1, 2018. Zehnder Rittling periodically makes changes to the design and/or specifications of its products. As a result, the design and specifications of each product at the time of order may be different than as
described herein. Please contact Zehnder Rittling's Sales Support staff at 716-827-6510 for specific information on current design and specifications. Designs, specifications and other information contained herein are not express
warranties, which are only as expressly set forth by Zehnder Rittling in its terms and conditions of sale. The latest version of this document is available at www.zehnder-rittling.com.
Rittling Cabinet Unit Heater
Submittal Data
Zehnder Rittling · 100 Rittling Blvd. · Buffalo, NY USA 14220
T 716-827-6510 · F 716-218-2805 · [e-mail] · www.zehnder-rittling.com
© Zehnder Rittling June 2018, English, subject to change without notice
4"
16"
M
K
7 1/8"
2"
J
L
18 3/8"
13 5/8"
2"
T
P
N
R
7 1/8"
5 5/8"
10 3/8"
3/8" wd. x 1" lg.
(4 places)
mounting slot
Electrical
end pocket
Front view
(less front panel)
C
* 8" B * 8"
(top outlet)
Piping access
Top view
section
Outlet opening centered
Fan speed
access section
6"
D
10"
RW-280
shown
Models RW, RWI and RC
Dimensions and data
Dimensional data
Coil J K L M NPRT
2 Row 15-3/4 4-7/16 16-9/16 5-3/16 7-7/16 5-3/16 8-1/4 4-7/16
3 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
4 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
Dimensional data
Unit size AB CD
Std. 6" Ext
02 38-3/16 44-3/16 22-3/16 23-5/8 20
03 44-3/16 50-3/16 28-3/16 29-5/8 26
04 50-3/16 56-3/16 34-3/16 35-5/8 32
06 62-3/16 68-3/16 46-3/16 47-5/8 44
08 68-3/16 74-3/16 52-3/16 53-5/8 50
10 76-3/16 82-3/16 60-3/16 61-5/8 58
12 86-3/16 92-3/16 70-3/16 71-5/8 68
* Add 6" per extended end selection. See chart for details.
RC-360
shown
1 row hot
water supply
Filter
positions
and 1 row
steam supply
and 1 row
steam return
Side view: Model RW and RC
2, 3 & 4 row hot
water return
1 row hot
water return
2, 3 & 4 row hot
water supply
2, 3 & 4 row hot
water supply
water return
1 row hot
and 1 row
water return
Side view: Model RWI
steam supply
steam return
and 1 row
water supply
2, 3 & 4 row hot
1 row hot
Filter positions
Front view
(Front outlet)
6"
24"
A 3"
2 3/8"
6"
4"
16"
M
K
7 1/8"
2"
J
L
18 3/8"
13 5/8"
2"
T
P
N
R
7 1/8"
5 5/8"
10 3/8"
3/8" wd. x 1" lg.
(4 places)
mounting slot
Electrical
end pocket
Front view
(less front panel)
C
* 8" B * 8"
(top outlet)
Piping access
Top view
section
Outlet opening centered
Fan speed
access section
6"
D
10"
RW-280
shown
Models RW, RWI and RC
Dimensions and data
Dimensional data
Coil J K L M NPRT
2 Row 15-3/4 4-7/16 16-9/16 5-3/16 7-7/16 5-3/16 8-1/4 4-7/16
3 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
4 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
Dimensional data
Unit size AB CD
Std. 6" Ext
02 38-3/16 44-3/16 22-3/16 23-5/8 20
03 44-3/16 50-3/16 28-3/16 29-5/8 26
04 50-3/16 56-3/16 34-3/16 35-5/8 32
06 62-3/16 68-3/16 46-3/16 47-5/8 44
08 68-3/16 74-3/16 52-3/16 53-5/8 50
10 76-3/16 82-3/16 60-3/16 61-5/8 58
12 86-3/16 92-3/16 70-3/16 71-5/8 68
* Add 6" per extended end selection. See chart for details.
RC-360
shown
1 row hot
water supply
Filter
positions
and 1 row
steam supply
and 1 row
steam return
Side view: Model RW and RC
2, 3 & 4 row hot
water return
1 row hot
water return
2, 3 & 4 row hot
water supply
2, 3 & 4 row hot
water supply
water return
1 row hot
and 1 row
water return
Side view: Model RWI
steam supply
steam return
and 1 row
water supply
2, 3 & 4 row hot
1 row hot
Filter positions
Front view
(Front outlet)
6"
24"
A 3"
2 3/8"
6"
Dimensions and data Model RW, RWI and RC
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
 Inlet grill optional
 Unit shown with left hand piping connections and right hand electrical connections as standard
 Right hand piping connections with left hand electrical connections available as an option
 Piping hand determined when facing the air outlet
 All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder at its base office
 See www.zehnder-rittling.com for any recent updates or changes
Dimensional data
Unit size
AB C Louvers Ducted opening
Std. 6" Ext. 6" Ext. x2 D E F G
02
38-3/16 44-3/16 50-3/16 22-3/16 24 20 618-3/8 5-1/8
03
44-3/16 50-3/16 56-3/16 28-3/16 30 26 624-3/16 5-1/8
04
50-3/16 56-3/16 62-3/16 34-3/16 36 32 630-3/16 5-1/8
06
62-3/16 68-3/16 74-3/16 46-3/16 48 44 642-3/16 5-1/8
08
68-3/16 74-3/16 80-3/16 52-3/16 54 50 648-3/16 5-1/8
10
76-3/16 82-3/16 88-3/16 60-3/16 62 58 656-3/16 5-1/8
12
86-3/16 92-3/16 98-3/16 70-3/16 72 68 666-3/16 5-1/8
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
 Inlet grille optional
 Unit shown with left hand piping connections and right hand electrical connections as standard
 Right hand piping connections with left hand electrical connections available as an option
 Piping hand determined when facing the air outlet
 All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder Rittling at its base office
 See www.zehnder-rittling.com for any recent updates or changes
Dimensions and data
Dimensional data
Unit size AB C Louvers Ducted opening
Std. 6" Ext. 6" Ext. x2 D E F G
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20 618-3/8 5-1/8
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26 624-3/16 5-1/8
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32 630-3/16 5-1/8
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44 642-3/16 5-1/8
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50 648-3/16 5-1/8
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58 656-3/16 5-1/8
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68 666-3/16 5-1/8
DIMENSIONS AND DATA
8
Models RW, RWI and RC

Revised June 1, 2018. Zehnder Rittling periodically makes changes to the design and/or specifications of its products. As a result, the design and specifications of each product at the time of order may be different than as
described herein. Please contact Zehnder Rittling's Sales Support staff at 716-827-6510 for specific information on current design and specifications. Designs, specifications and other information contained herein are not express
warranties, which are only as expressly set forth by Zehnder Rittling in its terms and conditions of sale. The latest version of this document is available at www.zehnder-rittling.com.
Rittling Cabinet Unit Heater
Submittal Data
Zehnder Rittling · 100 Rittling Blvd. · Buffalo, NY USA 14220
T 716-827-6510 · F 716-218-2805 · [e-mail] · www.zehnder-rittling.com
© Zehnder Rittling June 2018, English, subject to change without notice
4"
16"
2"
T
P
N
R
7 1/8"
5 5/8"
10 3/8"
M
K
7 1/8"
2"
J
L
18 3/8"
13 5/8"
3/8" wd. x 1" lg.
(4 places)
mounting slot
Electrical
end pocket
Front view
(less front panel)
C
* 8" B * 8"
RFRC-410
shown
Front view
(Front outlet)
6"
A + 3"
24"
3"
6"
A
2 3/8"
27"
1 row hot
2, 3 & 4 row hot
water supply
2, 3 & 4 row hot
steam supply
water supply
and 1 row
steam return
Side view: Model RRWI and RFRWI
water return
1 row hot
water return
and 1 row
Filter position
RFRW-340
shown
Top view
Piping
(top outlet)
Outlet opening centered
section
Fan speed
section
D or F
10"
E or G
1 row hot
water supply
Filter
positions
and 1 row
steam supply
and 1 row
steam return
Side view: Model RRW, RFRW, RRC and RFRC
2, 3 & 4 row hot
water return
1 row hot
water return
2, 3 & 4 row hot
water supply
Models RRW, RFRW, RRC,
RFRC, RRWI and RFRWI
Dimensions and data
Dimensional data
Unit
size
ABC Louvers Duct opening
Std. 6" Ext. DE F G
02 38-3/16 44-3/16 22-3/16 23-5/8 20 6 18-3/16 5-1/8
03 44-3/16 50-3/16 28-3/16 29-5/8 26 6 24-3/16 5-1/8
04 50-3/16 56-3/16 34-3/16 35-5/8 32 6 30-3/16 5-1/8
06 62-3/16 68-3/16 46-3/16 47-5/8 44 6 42-3/16 5-1/8
08 68-3/16 74-3/16 52-3/16 53-5/8 50 6 48-3/16 5-1/8
10 76-3/16 82-3/16 60-3/16 61-5/8 58 6 56-3/16 5-1/8
12 86-3/16 92-3/16 70-3/16 71-5/8 68 6 66-3/16 5-1/8
Dimensional data
Coil J K L M NPRT
2 Row 15-3/4 4-7/16 16-9/16 5-3/16 7-7/16 5-3/16 8-1/4 4-7/16
3 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
4 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A" and "H".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
* Add 6" per extended end selection. See chart for details.* Add 6" per extended end selection. See chart for details.
Dimensional data
Unit
size
ABC Louvers Duct opening
Std. 6" Ext. DE F G
02 38-3/16 44-3/16 22-3/16 23-5/8 20 6 18-3/16 5-1/8
03 44-3/16 50-3/16 28-3/16 29-5/8 26 6 24-3/16 5-1/8
04 50-3/16 56-3/16 34-3/16 35-5/8 32 6 30-3/16 5-1/8
06 62-3/16 68-3/16 46-3/16 47-5/8 44 6 42-3/16 5-1/8
08 68-3/16 74-3/16 52-3/16 53-5/8 50 6 48-3/16 5-1/8
10 76-3/16 82-3/16 60-3/16 61-5/8 58 6 56-3/16 5-1/8
12 86-3/16 92-3/16 70-3/16 71-5/8 68 6 66-3/16 5-1/8
4"
16"
2"
T
P
N
R
7 1/8"
5 5/8"
10 3/8"
M
K
7 1/8"
2"
J
L
18 3/8"
13 5/8"
3/8" wd. x 1" lg.
(4 places)
mounting slot
Electrical
end pocket
Front view
(less front panel)
C
* 8" B * 8"
RFRC-410
shown
Front view
(Front outlet)
6"
A + 3"
24"
3"
6"
A
2 3/8"
27"
1 row hot
2, 3 & 4 row hot
water supply
2, 3 & 4 row hot
steam supply
water supply
and 1 row
steam return
Side view: Model RRWI and RFRWI
water return
1 row hot
water return
and 1 row
Filter position
RFRW-340
shown
Top view
Piping
(top outlet)
Outlet opening centered
section
Fan speed
section
D or F
10"
E or G
1 row hot
water supply
Filter
positions
and 1 row
steam supply
and 1 row
steam return
Side view: Model RRW, RFRW, RRC and RFRC
2, 3 & 4 row hot
water return
1 row hot
water return
2, 3 & 4 row hot
water supply
Models RRW, RFRW, RRC,
RFRC, RRWI and RFRWI
Dimensions and data
Dimensional data
Unit
size
ABC Louvers Duct opening
Std. 6" Ext. DE F G
02 38-3/16 44-3/16 22-3/16 23-5/8 20 6 18-3/16 5-1/8
03 44-3/16 50-3/16 28-3/16 29-5/8 26 6 24-3/16 5-1/8
04 50-3/16 56-3/16 34-3/16 35-5/8 32 6 30-3/16 5-1/8
06 62-3/16 68-3/16 46-3/16 47-5/8 44 6 42-3/16 5-1/8
08 68-3/16 74-3/16 52-3/16 53-5/8 50 6 48-3/16 5-1/8
10 76-3/16 82-3/16 60-3/16 61-5/8 58 6 56-3/16 5-1/8
12 86-3/16 92-3/16 70-3/16 71-5/8 68 6 66-3/16 5-1/8
Dimensional data
Coil J K L M NPRT
2 Row 15-3/4 4-7/16 16-9/16 5-3/16 7-7/16 5-3/16 8-1/4 4-7/16
3 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
4 Row 16-9/16 3-1/16 17-1/8 4-13/16 6-1/8 4-13/16 7-7/16 3-1/16
Notes:
- 1, 2, 3 and 4 row coil supply and return 1/2" nominal (5/8" OD) all sizes.
- Left hand piping connections shown, right hand electrical as standard.
Piping hand determined when facing the air outlet.
- Unit length: for 6" extended end pocket add 6" to dimension "A" and "H".
- All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specificstions must be acceptrd by
Zehnder at its base office.
* Add 6" per extended end selection. See chart for details.* Add 6" per extended end selection. See chart for details.
Dimensional data
Unit
size
ABC Louvers Duct opening
Std. 6" Ext. DE F G
02 38-3/16 44-3/16 22-3/16 23-5/8 20 6 18-3/16 5-1/8
03 44-3/16 50-3/16 28-3/16 29-5/8 26 6 24-3/16 5-1/8
04 50-3/16 56-3/16 34-3/16 35-5/8 32 6 30-3/16 5-1/8
06 62-3/16 68-3/16 46-3/16 47-5/8 44 6 42-3/16 5-1/8
08 68-3/16 74-3/16 52-3/16 53-5/8 50 6 48-3/16 5-1/8
10 76-3/16 82-3/16 60-3/16 61-5/8 58 6 56-3/16 5-1/8
12 86-3/16 92-3/16 70-3/16 71-5/8 68 6 66-3/16 5-1/8
Dimensional data
Unit
size
AB C
Louvers
Duct opening H
Std. 6" Ext. 6" Ext. x2 D E F G Std. 6" Ext. 6" Ext. x2
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20 618-3/8 5-1/8 41-3/16 47-3/16 53-3/16
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26 624-3/16 5-1/8 47-3/16 53-3/16 59-3/16
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32 630-3/16 5-1/8 53-3/16 59-3/16 65-3/16
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44 642-3/16 5-1/8 65-3/16 71-3/16 77-3/16
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50 648-3/16 5-1/8 71-3/16 77-3/16 83-3/16
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58 656-3/16 5-1/8 79-3/16 85-3/16 91-3/16
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68 666-3/16 5-1/8 89-3/16 95-3/16 101-3/16
Dimensions and data
Models RRW, RFRW, RRC, RFRC, RRWI & RFRWI
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
 Unit shown with left hand piping connections and right hand electrical connections as standard
 Right hand piping connections with left hand electrical connections available as an option
 Piping hand determined when facing the air outlet
 All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder at its base office
 See www.zehnder-rittling.com for any recent updates or changes
Notes:
1 and 2 row coil supply and return 1/2" nominal (5/8" OD) all sizes
 Unit shown with left hand piping connections and right hand electrical connections as standard
 Right hand piping connections with left hand electrical connections available as an option
 Piping hand determined when facing the air outlet
 All listed dimensions are approximate and are subject to change without notice
 Modifications to the product specifications must be accepted by Zehnder Rittling at its base office
 See www.zehnder-rittling.com for any recent updates or changes
Dimensional data
Unit
size
AB C Louvers Duct opening H
Std. 6" Ext. 6" Ext. x2 D E F G Std. 6" Ext. 6" Ext. x2
02 38-3/16 44-3/16 50-3/16 22-3/16 24 20 618-3/8 5-1/8 41-3/16 47-3/16 53-3/16
03 44-3/16 50-3/16 56-3/16 28-3/16 30 26 624-3/16 5-1/8 47-3/16 53-3/16 59-3/16
04 50-3/16 56-3/16 62-3/16 34-3/16 36 32 630-3/16 5-1/8 53-3/16 59-3/16 65-3/16
06 62-3/16 68-3/16 74-3/16 46-3/16 48 44 642-3/16 5-1/8 65-3/16 71-3/16 77-3/16
08 68-3/16 74-3/16 80-3/16 52-3/16 54 50 648-3/16 5-1/8 71-3/16 77-3/16 83-3/16
10 76-3/16 82-3/16 88-3/16 60-3/16 62 58 656-3/16 5-1/8 79-3/16 85-3/16 91-3/16
12 86-3/16 92-3/16 98-3/16 70-3/16 72 68 666-3/16 5-1/8 89-3/16 95-3/16 101-3/16
Models RRW, RFRW, RRC,
RFRC, RRWI and RFRWI
Dimensions and data
9

Front view
29-1/4"
(Slope top unit)
A
26-1/2"
Damper opening
1-7/8"
D
3/8"
Motorized damper
Manual damper
Motor end
Dimensional data
Unit size A B C D
02 38-3/16 22-3/8 24 18-5/8
03 44-3/16 28-3/8 30 18-5/8
04 50-3/16 34-3/8 36 23-5/8
06 62-3/16 46-3/8 48 23-5/8
08 68-3/16 52-3/8 54 33-5/8
10 76-3/16 60-3/8 62 33-5/8
12 86-3/16 70-3/8 72 33-5/8
Notes:
Damper motor always on right side when viewing unit from front side.
All listed dimensions are approximate and are subject to change without
notice. Modifications to the product specifications must be accepted by
Zehnder Rittling at its base office.
Available for models RF and RS only.
Dimensions and data
DIMENSIONS AND DATA
10
Damper

Telescoping inner and
outer aluminum box
Unpainted aluminum louvered
inlet grille with internal bug screen
3 1/2"
A
Front View
Weep holes
2 5/8"
4" to 8"
1/2"
2 13/16"
Side View
Dimensional data
Model A Rough opening
WB-0203 24 22-1/2 x 3
WB-0406 29 27-1/2 x 3
WB-081012 39 37-1/2 x 3
Dimensions and data
11
Outside air wall box

Dimensions and data
Front view
RFRW-340
shown
Side view
Top view
10"
2"
A
H
24"
27"
A
H
For fully recessed units locate frame
flush with front
For partially recessed units locate
frame as needed
Use sheet metal screws (by others)
to secure trimframe to the unit.
Dimensional data
Unit size A H
02 38-3/16 41-3/16
03 44-3/16 47-3/16
04 50-3/16 53-3/16
06 62-3/16 65-3/16
08 68-3/16 71-3/16
10 76-3/16 79-3/16
12 86-3/16 89-3/16
Ships loose for field mounting
DIMENSIONS AND DATA
12
Wall seal kit

This installation and start-up instructions literature is for horizontal and vertical Cabinet Unit Heaters. Cabinet Unit Heaters
are hydronic terminal units designed for year-round heating. Your equipment is initially protected under the Zehnder Rittling
standard 2-year warranty provided the steps outlined in this manual for initial inspection, installation, periodic maintenance
and normal every day operation of the equipment are followed. This manual should be thoroughly reviewed prior to the
installation, start-up or maintenance of the equipment. If any questions arise, please contact your local Zehnder Rittling sales
representative or the factory before proceeding any further.
There are a multitude of options and accessories available with the equipment covered in this manual. For more specific
details on the included options and accessories, refer to the order acknowledgment, approved submittals and catalogs.
Upon delivery, examine the shipment against the bill of lading to make sure all of the units have been received and then check
each unit carefully for shipping damage. Any damage should be reported to the freight carrier and a claim should be filed
with them. Ensure the shipping company makes proper notation of any shortages or damage on all copies of the freight bill.
Concealed damage not discovered during unloading must be reported to the shipping company within 15 days of receipt of
the shipment.
All units are shipped F.O.B. factory. Therefore, Zehnder Rittling is not responsible for damage during transit. It is the
responsibility of the installing contractor to inspect and verify that the units shipped were in fact the correct model number,
voltage, etc. Any discrepancies should be reported to the local Sales Representative for immediate resolution prior to
unpackaging and installation. The factory should be notified of any warranty repairs required in writing before any corrective
action is taken. The factory must be fully informed of the expected costs before the work is begun. Zehnder Rittling is not
responsible for any repairs or alterations made by the purchaser without Zehnder Rittling’s written consent and will not accept
any back charges associated with these repairs or alterations. The return of damaged equipment will not be accepted without
written authorization from Zehnder Rittling.
A unit that has received a written Return Goods Authorization will be inspected by Zehnder Rittling upon receipt. Any damage,
missing parts, reworking or repackaging resulting from prior installation will constitute just cause for Zehnder Rittling to issue
partial credit.
Several components are shipped loose for field installation and to offer added protection during shipment and job site
storage. These items may include; thermostat, valve packages, remote temp sensors, etc.
General information
Receiving
GENERAL INFORMATION / RECEIVING
13

Never pressurize equipment beyond specified pressures as
shown on unit rating plate. Always pressure test with an inert
fluid such as water or dry nitrogen to avoid possible damage
or injury in the event of a leak or component failure during
testing.
Always protect adjacent flammable material when welding
or soldering. Use a suitable heat shield material to contain
sparks or drops of solder. Have a fire extinguisher readily
available.
Please follow standard safe practices regarding the handling,
installing or servicing of mechanical equipment. Read these
instructions thoroughly and follow all warnings or cautions
attached to the equipment. Consult local building codes and
the National Electrical Code(NEC) for special installation
requirements.
Understand the signal words: danger, warning and caution.
Identifies the most serious hazards which will result in severe
personal injury or death.
Signifies hazards that could result in personal injury or death.
Used to identify unsafe practices, which would result in minor
personal injury or product and property damage.
The manufacturer assumes no responsibility for personal
injury or property damage resulting from improper or
unsafe practices during the handling, installation, service
or operation of the equipment. The installation of Cabinet
Unit Heaters and all associated components, parts and
accessories shall be in accordance with the regulations of
all authorities having jurisdiction and must conform to all
applicable codes. It is the responsibility of the installing
contractor to determine and comply with all applicable codes
and regulations.
The installation of Cabinet Unit Heaters and all associated
components, parts and accessories which make up the
installation, shall be in accordance with the regulations
of all authorities having jurisdiction and must conform to
all applicable codes. Only trained and qualified service
personnel using good judgment and safe practices should
install, repair and/or service air conditioning equipment.
Untrained personnel can perform basic maintenance
functions such as cleaning coils and cleaning or replacing
filters. All other operations should be performed by trained
service personnel. When working on air conditioning
equipment, observe precautions in the literature, tags
and labels attached to the equipment and all other safety
precautions that may apply.
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical
shock or other hazardous conditions which may cause
serious personal injury and/or property damage. Consult a
qualified installer, service agency, or your sales representative
for information or assistance.
The equipment must always be properly supported by rigging
and lifting equipment. Any temporary supports used during
installation or maintenance must be designed to adequately
hold the equipment in place until equipment is permanently
fastened and set in its final location. All supports must meet
applicable local codes and ordinances.
All fastening devices must be designed to mechanically hold
the assembly in place without the ability to loosen or break
away due to system operation or vibration.
All power must be disconnected and locked out before any
installation or service is performed to avoid electrocution or
shock. More than one power source may be supplied to a
unit. Power to remote mounted units may not be supplied
through the unit.
Never use bulky or loose fitting clothing when working on any
mechanical equipment. Gloves should always be worn for
protection against heat, sharp edges and all other possible
hazards. Safety glasses should always be worn, especially
when drilling, cutting or working with chemicals.
Safety considerations
SAFETY CONSIDERATIONS
14

All units are carefully inspected at the factory throughout the
entire fabrication and assembly processes under Zehnder
Rittling’s stringent quality assurance program. All major
components and subassemblies such as motors, blowers,
coil, controls, valve package and paint quality are carefully
tested for proper operation, visually inspected and verified
for full compliance with factory standards. Operational
testing for some customer furnished components such as
pneumatic valves and DDC controllers may be a possible
exception.
Cabinet Unit Heaters are usually shipped on pallets of up
to 5 units. Each unit is factory tagged according to the
customer’s purchase order. This allows the unit, upon
removal from the pallet, to be taken directly to its’ assigned
space for immediate installation. Units should not be
installed at locations other than that designated on the tag.
Each unit is carefully packaged in a polyethylene plastic bag
for surface protection, placed in a cardboard container and
filled with kraft paper padding for shipment to avoid damage
during normal handling in the shipment process. It is the
sole responsibility of the customer to provide the protection
necessary to prevent vandalism and weather deterioration
of the equipment. Under no condition should the units be
left unprotected from the elements. If the equipment is
not needed immediately at the job site, it should be left in
its shipping carton and stored in a clean, dry area of the
building or in a warehouse. Do not remove any equipment
from its shipping package until it is needed for installation.
The equipment is NOT suitable for outdoor installations.
After determining the condition of the cardboard container
exterior, carefully remove each unit from the container
and inspect for hidden damage. At this time, check that all
shipped loose items such as wall mounted thermostats,
aquastats, remote temperature sensors, valve package, etc.,
are accounted for and placed in a safe area. Any hidden
damage should be recorded and immediately reported to
the carrier and a claim should be filed. In the event a claim
for shipping damage is filed, the unit, cardboard container,
and all packing must be kept for physical inspection by the
freight carrier.
Once the equipment is properly positioned on the job site,
cover the units with either a shipping carton, vinyl film, or
an equivalent protective covering. Cap open ends of piping
that is stored on a job site. Take special care to prevent
foreign materials from entering the units in areas where
painting, dry walling, or spraying of fireproof material,
etc., has not yet been completed as these materials may
accumulate on the motors and blower wheels. Foreign
material that accumulates within the units can prevent
proper start-up, necessitate costly clean-up operations, or
result in immediate or premature component failure. Before
installing any of the system components, be sure to examine
each pipe, fitting and valve, and remove any dirt or foreign
material found in or on these components. All manufacturer’s
warranties are void if foreign material is allowed to be
deposited on the motor or blower wheels of any unit. Some
job conditions may require some form of temporary unit
covering during construction.
DO NOT store or install units in corrosive environments or in
locations subject to temperature or humidity extremes (e.g.,
attics, garages, rooftops, etc.). Corrosive conditions and
high temperature or humidity can significantly reduce system
performance, reliability and overall service life.
Unpacking and preparation
UNPACKING AND PREPARATION
15

While all equipment is designed for durability and fabricated
with heavy gauge materials and may present a robust
appearance, great care must be taken to assure that no
undue force is applied to the coil, piping, or other delicate
components such as control boards during handling.
Wherever possible, all units should be maintained in an
upright position and handled by the chassis, plenum
sections or as close as possible to the mounting points.
In the case of a fully exposed cabinet unit, the unit must
obviously by handled by the exterior casing. Gloves should
be worn when handling finished, painted units and should
never be set down on unclean, hard surfaces. Failure to
follow these instructions may lead to scratching or gouging
of the finished surface.
Although Zehnder Rittling does not become involved
with the design and selection of support methods and/or
components, it should be recognized that unacceptable
operating characteristics and/or performance may result
from poorly implemented unit support. Additionally, proper
clearance must be provided for service and removal of the
equipment.
Anchoring the equipment in place is accomplished by using
the mounting points provided, and positioning the unit on
a LEVEL plane. Vertical units are designed to be bolted to
the wall structure through the slotted wall mounting holes in
the chassis, used for anchoring to pre-installed wall studs.
Horizontal units are provided with slotted ceiling mounting
brackets where hanging rod and rubber-in-shear or spring
vibration isolators, supplied by others, can be used for
proper suspension and vibration isolation.
The type of mounting device is a matter of choice, however
the mounting point should always be that provided in the
chassis or cabinet.
Improper mounting could result in the unit falling from its
position, causing personal injury or even death.
After mounting the unit, it is then ready for the various
service connections such as water and electrical. At this
time it should be verified that the proper types of services
are actually provided to the unit. On those units requiring hot
water, the proper line size and water temperature should be
available to the unit.
On units with steam heating coils, the proper line sizing and
routing should be verified. The maximum steam pressure
should never exceed 15 psig. The drain piping and steam
trap, supplied by others, should be sized and routed to allow
for proper condensate flow.
The electrical service to the unit should be compared to
the unit nameplate to verify compatibility. The routing and
sizing of all piping, and the type and sizing of all wiring
and other electrical components such as circuit breakers,
disconnect switches, etc., should be determined by the
individual job requirements and should not be based on the
size and/or type of connection(s) provided on the equipment.
Verify the electrical conductor size is suitable for the
distance to the equipment connection and will support the
equipment electrical load. All installations should be made
in compliance with all governing codes and ordinances.
Compliance with all codes is the responsibility of the
installing contractor.
Provide access clearance for electrical enclosure per local
and national electrical code requirements, minimum of 36".
It is recommended to leave 36" access on pipe connection
side. It is also recommended to leave room for filter removal,
equivalent to the physical size of the filter.
16
Handling and installation
HANDLING AND INSTALLATION

17
Submittals and product literature detailing unit operation,
controls and connections should be thoroughly reviewed
before beginning the connection of the heating medium to
the unit.
All shipped loose valve packages should be installed as
required and all service valves should be checked for proper
operation.
All coil and valve package connections are to be made with
a sweat or solder joint. Care should be taken to assure that
no components in the valve package are subjected to a high
temperature which may damage seals or other materials.
Many two-position electric control valves, depending on
valve operation, are provided with a manual opening lever.
This lever should be placed in the “open” position during all
soldering or brazing operations. In accordance with good
soldering and brazing practices, valve bodies should be
wrapped with a wet rag to help dissipate the heat.
If the valve package connection at the coil is made with a
union, the coil side of the union must be prevented from
twisting during tightening to prevent damage to the coil
tubing. Over-tightening must be avoided to prevent distorting
the union seal surface and destroying the union, ultimately
causing a leak.
Secure the union nut hand-tight and then tighten no more
than an additional 1/4 turn.
The inlet supply connection is marked at the appropriate coil
stub-out with the other coil stub-out being the outlet return
connection.
After the connections are completed, the system should be
tested for leaks. Since some components are not designed
to hold pressure with a gas, hydronic systems should be
tested with water. Test pressure must not exceed 250 psig.
Pressure testing should be completed prior to sheet rocking,
finished floors, painting, caulking, etc.
All water coils must be protected from freezing after initial
filling with water. Even if the system is drained, unit coils may
still hold enough water to cause damage when exposed to
temperatures below freezing.
In the event that leaking or defective components are
discovered, the Zehnder Rittling Sales Representative must
be notified before any repairs are attempted. All leaks should
be repaired before proceeding with the installation.
After system integrity has been established, it is
recommended that the piping be insulated in accordance
with the project specifications. This is the responsibility of
the installing or the insulation contractor. Zehnder Rittling
will not accept any charges associated with re-insulating
piping if the installing contractor failed to establish system
integrity prior to insulating.
Hot water connections
HOT WATER CONNECTIONS

18
All ductwork and or supply and return grilles should
be installed in accordance with the project plans and
specifications. If not included on the unit or furnished from
the factory, supply and return grilles should be provided as
recommended in the product catalog.
For units with no return air ductwork, check local code
requirements for possible application restrictions. All units
must be installed in non-combustible and non-hazardous
areas.
Some models are designed to be connected to ductwork
with a minimum amount of external static pressure. These
units may be damaged by operation without the proper
ductwork connected. Consult the approved submittals
and the product catalog for unit external static pressure
limitations.
Units provided with outside air should have some form of low
temperature protection to prevent coil(s) from freezing. This
protection may be a low-temperature thermostat to close the
outside air damper, a preheat coil to temper the outside air
before it reaches the unit, or any other protective method.
It should be noted that none of these methods will
adequately protect a coil in the event of power failure.
The safest method of freeze protection is to use glycol in
the proper percent solution for the coldest expected air
temperature.
Flexible duct connections should be used on all air handling
equipment to minimize vibration transmissions. Insulation
and ductwork should be installed to allow servicing of
equipment including motors, blowers, filters, etc.
Zehnder Rittling assumes no responsibility for undesirable
system operation due to improper design, equipment or
component selection, and/or installation of base unit,
ductwork, grilles and other related components.
Ductwork connections
DUCTWORK CONNECTIONS