Noritz proTOUGH NR981-OD Use and care manual

NR981-OD, NR981-DVC,NR981-SV
NC1991-OD, NC1991-DVC
NR98OD(GQ-2857WX US), NR98DVC(GQ-2857WX-FFA US)
NR98SV(GQ-2857WX-F US)
NC199OD(GQ-2857WZ US), NC199DVC(GQ-2857WZ-FFA US)
SKJ70VC
Rev.05/16
Model Include :
HeatExchangerReplacement
Page1
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Phone866‐766‐7489Fax714‐241‐1196
ServiceRepresentative.Anyunauthorizeduseofthismanualmayresultinvoidingthewarranty.
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ThisinstructionalmanualisonlyintendedforusebyaqualifiedserviceprofessionalorauthorizedNoritz

Heat Exchanger Replacement Procedure
1. Drain the unit as shown in following procedure 1. Drain the unit as shown in following procedure
Manual Draining
Page 2
Drainage using the Remote Controller
Procedure
* RC-9018M
* RC-7651M
Drain Plugs
Each drain plug might not be
visible if insulation is installed
around the piping.

Heat Exchanger Replacement Procedure
Diagram
Page 3
Procedure
2. Remove Front Cover
(1)Disconnect electrical power to the unit
(2)Turn off gas and water
(3) Remove 4 screws
3. Remove Lightning Protection
(1) DVC model for residential only ; Remove 2 screws
and unplug Remote Controller
that hold Mounting plate for Remote Controller,
(2) Let Remote Controller hang outside of the unit
(3) Remove 2 screws that hold the Lightning
Protection Plate (Whichever the unit is in case
(4) Let Lightning Protection hang outside of the unit
No.2, 3, 4)
Case No.3 (SV model)
Case No.2 (OD model)
(1)
Case No.4 (DVC model for commercial)
Case No.1 (DVC model for residential)
Ex.) OD model

Heat Exchanger Replacement Procedure
Diagram
4. Unplug all wires that attach to the wiring harness
and the body of the water heater
(1) Loosen the wire anchor from left side of the case,
unplug Freeze Prevention Heater
(2) Unplug Thermistor - Heat Exchanger
(3) Remove Cable Tie,
unplug Wiring for Remote Controller
(4) Unplug Freeze Prevention Heaters (4),
Water Servo - Main, - Bypass,
and Thermistor - Hot Water
(5) OD model only ; Unplug wiring for Power supply cord
(6) Remove Cable Tie,
unplug Wiring for Fan Motor, Water Flow Sensor,
Thermistor - Cold Water, -Air Inlet
and Wiring for Manifold Plate
Page 4
Procedure
(1)
(2)
(3)
(4)
(6)
(5)
Cable Tie
Cable Tie

Heat Exchanger Replacement Procedure
Diagram
(7) Unplug wiring for Igniter
(8) Loosen the wire anchor from right side of the case,
unplug High Limit Switch,
SV, DVC model only ; Unplug Freeze Prevention
Heater (2)
(9) Unplug Thermistor-Scale Detection*
(10) Unplug Thermal Fuse (2)
(11) Unplug Flame Rod and Ignition Plug
(12) Remove screw that hold Circuit Board
(13) Let all wires and Circuit Board hang outside of the unit
Page 5
Procedure
(10)
(13)
(7)
(11)
(12)
(8)
(8)
(8)
Thermistor - Scale Detection
(9)
*The following models have "Thermistor
- Scale Detection"
NR98OD(GQ-2857WX US)
NR98DVC(GQ-2857WX-FFA US)
NR98SV(GQ-2857WX-F US)
NC199OD(GQ-2857WZ US)
NC199DVC(GQ-2857WZ-FFA US)
Ex.) SV model

Heat Exchanger Replacement Procedure
Diagram
5. SV, DVC model only ; Remove Case Top Cover
from top of the unit
(1) Disconnect the venting from the unit
(2)SV model only ; Remove 6 screws
and remove 2 Case top Covers of the unit,
Gasket - Exhaust Flue and set aside.
(3) DVC model only ; Remove 2 screws
and remove Case Top Cover of the unit and set aside.
6. DVC model only ; Remove Tube - Metal Back
Pressure Tube
(1) Remove 1 screw on Exhaust box
that attach the tube
(2) Remove the tube from Exhaust box
Page 6
Procedure
(2)
(3)
(2)
Gasket - Exhaust Flue
SV model
SV model
DVC model
DVC model

Heat Exchanger Replacement Procedure
Diagram
7. Remove Manifold Plate
(1) Remove 4 big silver screws on Manifold Plate
that attach the Manifold Plate to Burner
(2) Remove "C" Clamp
(3) Locate inlet pipe to Manifold Plate and push up,
remove the Manifold Plate
8. Remove Water Servo - Bypass
(1) Remove 2 "C" Clamp
(2) Remove Water Servo - Bypass
9. Disconnect a pipe from Water Flow Sensor
(1) Remove "C" Clamp,
disconnect a pipe from Water Flow Sensor
Page 7
Procedure
(1)
(2)
(3)
(1)
Water Servo-Bypass
Water Flow Sensor

Heat Exchanger Replacement Procedure
Diagram
10. Disconnect a pipe from Water Servo - Main
(1) Remove "C" Clamp,
disconnect a pipe from Water Servo - Main
11. Remove the assembly from Case
(1) Remove 2 set screws on the bottom of Burner
(2) Remove 2 set screws near the top of the case
DVC model only ;
Remove 4 set screws near the top of the case
(3) Exhaust Box, Copper Heat Exchanger (CU HE),
Burner, and Fan Motor will come out in one section,
remove from the unit
Page 8
Procedure
(1)
(2)
(1)
(2)
Water Servo-Main
DVC model
SV model

Heat Exchanger Replacement Procedure
Diagram
12. Replacing the gasket
(1) OD model only ;
Remove Gasket on the front of Exhaust Box,
and reinstall Gasket onto new Exhaust Box
13. Remove CU HE
(1) Remove 12 screws holding Burner to CU HE
(2) Separate Burner from CU HE
14. Remove the heat exchanger components from
old heat exchanger and put on new heat exchanger
(1) Front side: Freeze Prevention Heater,
and Thermistor - Heat Exchanger
(2) Right side: High Limit Switch
SV, DVC model only ; Freeze Prevention
Heater (Secure to put Freeze Prevention Heater on
same position)
(3) Back side: Thermistor - Scale Detection*
Remove Packing on CU HE
Remove the small screw(M3×6) on CU HE that
holding Thermistor-Scale Detection
(4) Under side: Freeze Prevention Heater on water outlet
pipe, and Freeze Prevention Heater on water inlet pipe
(Secure to put Freeze Prevention Heater on
same position)
Page 9
Procedure
(4)Under side
(1)
(1)Front side
(2)Right side
Gasket
Thermistor - Scale Detection
Packing
- for holding Thermistor
(3)Back side
*The following models have "Thermistor
- Scale Detection"
NR98OD(GQ-2857WX US)
NR98DVC(GQ-2857WX-FFA US)
NR98SV(GQ-2857WX-F US)
NC199OD(GQ-2857WZ US)
NC199DVC(GQ-2857WZ-FFA US)
Wiring Harness of Thermistor - Scale Detection
The following models have "Thermistor - Scale
Detection"
NR98OD(GQ-2857WX US)
NR98DVC(GQ-2857WX-FFA US)
NR98SV(GQ-2857WX-F US)
NC199OD(GQ-2857WZ US)
NC199DVC
(
GQ-2857WZ-FFA US
)

Heat Exchanger Replacement Procedure
Diagram
(4) Attach Thermal Fuse, 4 Clamps, and Harness Clip
on 4 sides of CU HE, see 4 views of CU HE to
make sure Thermal Fuse is routed correctly
Page 10
Procedure
Front side
Back side
Clamp
Left side
Keep Thermal Fuse straight
Right side
NR981-OD/DVC/SV
NC1991-OD/DVC
Clamp
Back side
NR98OD/SV/DVC(GQ-2857WX＊＊)
NC199OD/DVC(GQ-2857WZ＊＊)
Secure the Thermistor-Scale Detection with screw(M3×6) on CU HE
NOTE ; Only tighten by a hand screwdriver (No Drills). Not need to attach the Packing
(for holding Thermistor - Scale Detection) when replacement.
To hold Wiring Harness of Thermistor - Scale Detection, tie the Wiring Harness
with Harness Clip.
Wiring Harness of Thermistor-Scale Detection
DVC and SV model have 2 Prevention Heaters on bended pipe
Make sure Wiring Harness does not contact with Freeze Prevention
◆Tie "Thermal Fuse" and "High Limit Switch" with Harness Clip
◆Tie "Thermal Fuse", "High Limit Switch" and "Thermistor - Scale Detection"
with Harness Clip
Harness Clip
The end of Insulation tube (Black)
and Inlet Pipe of CU HE are lined up

Heat Exchanger Replacement Procedure
Diagram
15. Replace Gasket
(1) Remove old burner Gasket and replace with new one
16. Place new O - Rings on new CU HE
(1) Inlet to CU HE
(2) Outlet from CU HE
(3) Bypass from CU HE
Page 11
Procedure
(1)
(1)
(2)
(3)

Heat Exchanger Replacement Procedure
Diagram
17. Replace Burner, and CU HE
(1) Attach 12 screws around perimeter of Burner and CU HE
18. Replace the assembly back inside the case
(1) Secure 2 set screws near the top of the case
DVC model only ;
Secure 4 set screws near the top of the case
(2) Secure 2 set screws on the bottom of Burner
Page 12
Procedure
(1)
(1)
(2)
(1)
SV model
DVC model

Heat Exchanger Replacement Procedure
Diagram
19. Replace Case Top Cover on top of the unit
DVC model only ;
(1) Attach Case Top Cover to the unit
and secure 2 screws
SV model only ;
(1) Attach Big Case Top Cover to the unit and secure
4 screws
(2) Place Gasket - Exhaust Flue on Exhaust pipe
(3) Attach Small Case Top Cover to the unit and secure
2 screws
(4) Reconnect the venting to the unit
Page 13
Procedure
(1)
(
1
)
(2)
(3)
DVC model
SV model

Heat Exchanger Replacement Procedure
Diagram
20. Reconnect a pipe to Water Servo - Main
(1) Insert a pipe to Water Servo - Main,
and attach "C" Clamp
21. Reconnect two pipes to Water Servo - Bypass
(1) Replace Water Servo - Bypass
(2) Attach 2 "C" Clamp
22. Reconnect a pipe to Water Flow Sensor
(1) Insert a pipe to Water Flow Sensor,
and attach "C" Clamp
Page 17
Page 14
Procedure
(1)
(1)
Water Servo-Main
Water Servo-Bypass
Water Flow Sensor

Heat Exchanger Replacement Procedure
Diagram
23. Replace Manifold Plate
(1) Secure the Manifold Plate to Burner with 4 big
silver screws
(2) Secure gas pipe of Manifold Plate to gas inlet fitting
with "C" Clamp
24. Replace Tube - Metal Back Pressure Tube
DVC model only ;
(1) Attach Tube with 1 screw.
Page 15
Procedure
(1)
(2)
DVC model

Heat Exchanger Replacement Procedure
Diagram
25. Reconnect all wires that attach to the wiring harness
and the body of the unit
(1) Insert Circuit Board and attach with screw
(2) Plug Flame Rod and Ignition Plug
(3) Plug wiring for Igniter
(4) Plug High Limit Switch
SV, DVC model only ; Plug Freeze Prevention Heater (2)
(5) Plug Thermistor - Scale Detection*
(6) Plug Thermal Fuse (2)
(7)Ｔie all wires (except for Ignition Wire) with the anchor
from right side of the case
Page 16
Procedure
(6)
(3)
(2)
(1)
(4)
(4)
(4)
Thermistor - Scale Detection
(5)
(7)
(7)
Caution!
1. Don't tie Ignition Wire with the anchor.
2.Set the Ignition wire behind of other wires.
Caution!
1. Don't tie Ignition Wire with the anchor.
2.Set Ignition wire behind of other wires.
*The following models have "Thermistor
- Scale Detection"
NR98OD(GQ-2857WX US)
NR98DVC(GQ-2857WX-FFA US)
NR98SV(GQ-2857WX-F US)
NC199OD(GQ-2857WZ US)
NC199DVC(GQ-2857WZ-FFA US)

Heat Exchanger Replacement Procedure
Diagram
(6) Plug Freeze Prevention Heater
Tie the wire anchor from left side of Case
DVC model only ; Don't tie the Tube with the anchor
(7) Plug Themistor - Heat Exchanger
(8) Plug Wiring for Remote Controller,
tie Cable Tie
(9) Plug Freeze Prevention Heaters (4),
Water Servo - Main, - Bypass,
and Thermistor - Hot Water
(10) OD model only ; Plug wiring for Power supply cord
(Yellow connector)
(11) Plug Wiring for Fan Motor, Water Flow
Sensor, Thermistor - Cold Water, -Air Inlet
and Wiring for Manifold Plate,
And then tie wirings with Cable Tie
Page 17
Procedure
(6)
(7)
(8)
(9)
(11)
OD model only
(
10
)
(6)
z
(7)
Tube
(DVC model)
Caution!
Don't tie the Tube with the anchor.
Cable Tie
Cable Tie
*NR98OD/SV/DVC(GQ-2857WX＊＊) and NC199OD/DVC(GQ-2857WZ＊＊)
have "Blue connector" for Scale Flushing
NOTE ; Don't connect this blue connector when replacing
Heat Exchanger
Disconnected

Heat Exchanger Replacement Procedure
Diagram
(1) DVC model for residential only ;
Page 18
Procedure
(Whichever the unit is in case No.2, 3, 4)
26. Replace Lightning Protection
replace Remote Controller, plug Remote Controller,
and attach the Mounting plate for Remote Controller
(2) Attach Lightning Protection Plate with 2 screws
with screw
Case No.3 (SV model)
Case No.2 (OD model)
(1)
Case No.1 (DVC model for residential)
Case No.4 (DVC model for commercial)

Heat Exchanger Replacement Procedure
Diagram
27. Check for water leak
(1) Secure 3 drain valves
(2) Turn on water inlet valve slowly (check for
leaks around "C" Clamps)
(3) If you get leaks, close water inlet valve
Re-secure "C" Clamps of leaking points
28. Check for gas leaks and doing trial operation
(1) Turn on gas supply valve
(2) Turn on the unit
Check for leaks around Manifold Plate and joining areas
For example ; Between Burner and CU HE
(3) If you get leaks, Close gas supply valve
Re-secure "C" Clamps of leaking points
29. Replace Front Cover
(1) Secure Front Cover with 4 screws
30. Check for correct operation of the water heater.
The following steps are for "NR98OD/DVC/SV(GQ-2857WX**)"
and "NC199OD/DVC(GQ-2857WZ**)"
(1) Turn on the remote controller
The water heater does not need to run now
(Do not open the water outlet valve and faucet)
(2) Press and hold both the "UP(▲)" and "DOWN(▼)" buttons
simultaneously for more than 2 seconds to enter
the Maintenance Monitor mode*
"03" will first appear on the remote controller
*The maintenance monitor data No. will appear on the
display for 2 seconds, and then the data will appear
(Type A remote controller only)
(3) Push the "UP(▲)" button until you see the data No.35**
**The data No.35 shows the "Temperature of Thermistor-
Scale Detection
(4) Turn on the gas supply valve, and then open the water
supply valve and faucet (water outlet valve) to run
the water heater for at least 1 minute.
(5) Check whether the data No.35 rises when the water
heater is running
(The water heater operation is correct if it displays more
than 32°F)
If the temperature does not rise or displays 32°F, then the
connection to the Thermistor-Scale Detection need to be
checked and repeat (1) - (5) in step 30
(6) Press and hold both the "UP(▲)" and "DOWN(▼)" buttons
simultaneously for more than 2 seconds to return
normal mode
Page 19
Procedure
(1)
Ex.) OD model
Ex.) This shows the data No.35 "75°F"
(Thermistor-ScaleDetection detects "75°F)
Ex.) This shows the data No.35 rises "75°F" to
"125°F" when the water heater is running
Type A
Type B
2 seconds
later