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92 Operating the Boiler

When Installing the Cascade System

When using the recirculation feature in the cascade system , you 

can choose commands in the menu to preheat according to the 

set DHW temperature. (Refer to “8.2 Cascade System - Recirculation 

System Application Example” for details on installing.)

Note

For water heater(s) that are connected to the 

recirculation line, each unit must be set to the proper 

recirculation mode.

Item

Description

1. Always On

Set to repeat DHW Recirculation 

(default).

2. Weekly*

The user can choose commands for 

DHW Recirculation on a weekly basis.

  1.  1 Day: Schedule a command for the 

week.

  2.  3 Day: Schedule commands for 

Weekdays, Saturdays, and Sundays.

  3.  7 Day: Schedule commands for each 

day of the week.

*  To choose this option you must set up the Time setting in the 

Configuration menu.

Set the Weekly Schedule

When setting up the Weekly option, select ‘Weekly,’ and select 

between 1 Day, 3 Day, and 7 Day to go to the Schedule menu.

Working

Not working

Rotate the Command Dial (

) to choose the scheduled time. You 

can choose the time in 30 minutes intervals. To finalize the weekly 

schedule settings, press and hold the Command dial (

) for more 

than 2 seconds. 

External Recirculation

When using the External Recirculation feature, you can  choose 

commands in the menu to preheat according to the set DHW 

temperature.

Item

Description

1. Always On

Set to repeat DHW Recirculation.

2. Intelligent*

Set to detect DHW use for a week and 

repeat the detected cycle.

3. Weekly*

The user can choose commands for 

DHW Recirculation on a weekly basis.

  1.  1 Day: schedule a command for the 

week.

  2.  3 Day: schedule commands for 

Weekdays, Saturdays, and Sundays.

  3.  7 Day: schedule commands for each 

day of the week.

4. Aquastat

Set to use an aquastat for DHW 

Recirculation.

5. HotButton 

(Manual)

Set to use additional installations 

(HotButton) for Recirculation. 

*  To choose this option you must set up the Time settings in the 

Configuration menu.

Note

If there is a SH Demand signal during external 

recirculation, pre-heating will take priority, and space 

heating will start afterwards.

Summary of Contents for NFC-175

Page 1: ...ructions If you cannot reach your gas supplier call the fire department Installation and service must be performed by a qualified installer service agency or the gas supplier The installation must con...

Page 2: ...s located in a crawl space unless the appliance is located in a detached uninhabitable garage For all residential dwellings a carbon monoxide detector must also be present on each habitable level of t...

Page 3: ...Switch 1 6 switch unit 60 6 2 Dip Switch 2 8 switch unit 60 7 Connecting the Power Supply 62 8 Installing a Cascade System 63 8 1 Connecting Water Supplies 63 8 2 Cascade System Recirculation System A...

Page 4: ...bor s phone call your gas provider and follow their instructions If you cannot reach your gas provider call the fire department Do not return to your home until authorized by your gas supplier or the...

Page 5: ...WARNING Do not store or use gasoline or other flammable liquids near this boiler Doing so may result in fire or explosion Do not place combustibles such as newspapers or laundry near the boiler or ve...

Page 6: ...130 F 55 C 10 seconds 120 F 49 C 10 minutes 100 F 37 C very low scald risk DANGER HOT BURN To prevent burns Use the lowest operating temperature setting necessary to provide comfortably hot water If y...

Page 7: ...Conversion Kit Outdoor Temperature Sensor and Cable Air Vent Bushing 3 4in to 1 2in Condensate Trap System Temperature Sensor NFC 175 200 Manifold System for single boilers 1 About the Boiler PRV Air...

Page 8: ...NFC 200 18 199 183 159 95 Note 1 Ratings are the same for natural gas models converted to propane use 2 Based on U S Department of Energy DOE test procedures 3 The net AHRI water ratings shown are bas...

Page 9: ...nal Recirculation Pump Grundfos UPS 15 78 CIL2 Part Number 30021636A 0 5 10 15 20 25 30 0 2 4 6 8 10 12 14 16 0 2 4 6 8 10 12 14 16 FT of Head P psi Flow Rate GPM NFC Flow Performance Curve NFC 175 20...

Page 10: ...ption Less than 15 amperes Materials Casing Cold rolled carbon steel Heat Exchangers Stainless Steel Venting Exhaust 2 in or 3 in PVC CPVC approved polypropylene 2 in or 3 in Special Gas Vent Type BH...

Page 11: ...ts are included in the Appendixes Intake Air Air Intake Pipe Exhaust Fan Motor Assembly Dual Venturi APS PCB Power Switch PRV Air Vent Connection Gas Pipe Mixing Chamber Igniter Flame Rod Igniter Tran...

Page 12: ...changer APS Power Switch Mixing Valve 3 Way Valve Heating Return Gas Valve ASME Name Plate Mixing Chamber Intake Air Filter Flame Rod Igniter Circulation Pump Water Adjust Valve DHW Exchanger Water Fi...

Page 13: ...Vent Connection 3 4 in D Heating Supply 1 in E Heating Return 1 in F Gas Connection 3 4 in G Condensate Outlet 1 2 in H Cold Water Inlet DHW 3 4 in I Hot Water Outlet DHW 3 4 in J Auto Feeder Inlet Ma...

Page 14: ...o not install the boiler If conversion to Propane Gas is required the included gas conversion kit must be used Refer to 12 1 Gas High Altitude Conversion on page 103 for details WARNING Ensure that th...

Page 15: ...d upper container Removing the Wood Pallet and the Pallet Brackets 1 Loosen the six screws that secure the wood pallet on the bottom left and right sides of the boiler 2 Remove the accessory box the w...

Page 16: ...tion code for hydronic heating systems and any local codes Access to Utilities Water the installation location should be near where the domestic water supply enters the building Gas the installation l...

Page 17: ...required by local codes whichever is greater Maintain a minimum clearance of 4 ft 1 2 m from heating and cooling vents Do not enclose the vent termination Install the exhaust vent in an area that is f...

Page 18: ...milar items do not obstruct access to the boiler or its venting High Elevation Installations This unit may be installed at elevations up to 10 100 ft 3 078 m for use with natural gas and propane Refer...

Page 19: ...e warranty and may result in property damage fire serious injury or death 3 Installing the System Piping 3 1 1 Guidelines for a Space Heating Installation Read and follow the guidelines listed below t...

Page 20: ...up water adds oxygen and minerals to the system that may lead to heat exchanger failure Failure to follow these instructions may result in poor performance unnecessary wear of system components and pr...

Page 21: ...be installed in the space heating piping to prevent excessive pressure from building in the system See the examples of system application at the end of this section for the installation location Refe...

Page 22: ...the discharge piping of the pressure relief valve so that hot water does not splash on the operator or equipment Attach the discharge line to the pressure relief valve and install the end of the line...

Page 23: ...l Secondary Drinking Water Regulations 40 CFR Part 143 3 If you suspect that your water is contaminated in any way discontinue use of the DHW and contact an authorized technician or licensed professio...

Page 24: ...osed water supply system Contact the water supplier or local plumbing inspector on how to correct the situation Do not plug the relief valve Navien is not responsible for performance issues of the dom...

Page 25: ...ppliance may be needed Consult your local code requirements to determine if this appliance is required Refer to the following illustration for a typical DHW piping example for the boiler Cold Water Su...

Page 26: ...usage rate of the boiler During the first year of operation the neutralizer should be checked every few months for depletion and replaced as needed c From the boiler into a laundry tub Note The botto...

Page 27: ...recommended The condensate from the appliance flows through the neutralizing media and increases the pH of the condensate An increased pH prevents corrosion of the installation s drainage system and t...

Page 28: ...s below the minimum level required by the local water authority If the pH level is not specified replace the neutralizing media when the pH is below 6 0 For replacement media contact your local Navien...

Page 29: ...it will damage the boiler Such damage is not covered by the warranty and may result in property damage severe personal injury or death Perform a fill test after installing the boiler s water system to...

Page 30: ...Installations must comply with all local codes In Massachusetts a vacuum relief valve must be installed in the cold water line per 248 CMR Air Removal The boiler and system piping layout must be conf...

Page 31: ...cal building codes or state regulations Check the local building codes and state regulations thoroughly before installation and comply with them fully Air Handler Interface The Navien NFC boiler can c...

Page 32: ...are intended to explain the system piping concept only Install a NaviClean filter in the system return to remove foreign objects from the system Foreign objects inside the system may result in abnorm...

Page 33: ...jects from the system Foreign objects inside the system may result in abnormal system operation Refer to 3 4 Filling the System on page 28 for make up water connections and refer to the requirements o...

Page 34: ...select external recirculation refer to the combi pre heat and external recirculation sections in 11 3 4 Setting the DHW Operation on page 90 for details N A H DHW PRI L N L N L N L N L Z3 Z2 Z1 AC24VN...

Page 35: ...L Z3 Z2 Z1 Recirculation pump max 2 5 A Recirculation Pump Wired HotButton Wired HotButton Pump Ground NaviCirc Sold Separately DHW Supply Return Water City Water Supply Check Valve Recirculation Pum...

Page 36: ...R T S_ZONE3 R W C N A H DHW PRI L N L N L N L N L Z3 Z2 Z1 Recirculation Pump Pump Ground DHW Supply Return Water City Water Supply Check Valve Check Valve Recirculation Pump max 2 5A A Taco 008 BC6 o...

Page 37: ...R W C N A H DHW PRI L N L N L N L N L Z3 Z2 Z1 AC24VN AC24VL lLWCO R W C R W C R W C T S_CH_ZONE1 T S_ZONE2 SUPPLY TEMPERATURE SENSOR RETURN OUTDOOR T S_ZONE3 R W C T S_Recir P 2 1 Aquastat Recircula...

Page 38: ...n the controls Wiring errors can cause abnormal and dangerous operation Verify proper operation after servicing Note The installation must comply with National Electrical Code and any other national s...

Page 39: ...URE SENSOR RETURN OUTDOOR T S_ZONE3 R W C NC NC COM NC NC COM LWCO AC24VL AC24VN NC NC COM ZONE1 ZONE2 ZONE3 AC24VN AC24VL lLWCO R W C T S_Recir P R W C R W C T S_ZONE1 T S_ZONE2 SUPPLY TEMPERATURE SE...

Page 40: ...OM LWCO AC24VL AC24VN NC NC COM ZONE1 ZONE2 ZONE3 AC24VN AC24VL lLWCO R W C T S_Recir P R W C R W C T S_ZONE1 T S_ZONE2 SUPPLY TEMPERATURE SENSOR RETURN OUTDOOR T S_ZONE3 R W C Pump Ground Thermostat...

Page 41: ...ump max 2 5 A Pump Ground NC NC COM NC NC COM LWCO AC24VL AC24VN NC NC COM ZONE1 ZONE2 ZONE3 AC24VN AC24VL lLWCO R W C T S_Recir P R W C R W C T S_ZONE1 T S_ZONE2 SUPPLY TEMPERATURE SENSOR RETURN OUTD...

Page 42: ...S_CH_ZONE1 T S_ZONE2 SUPPLY TEMPERATURE SENSOR RETURN OUTDOOR T S_ZONE3 R W C N A H DHW PRI L N L N L N L N L Z3 Z2 Z1 Zone pump 1 max 2 5 A Zone pump 2 max 2 5 A Zone pump 3 max 2 5 A Recirculation p...

Page 43: ...zones more efficiently by minimizing unnecessary pump operation The communication link also provides an optimal control environment for freeze protection AC24VN AC24VL lLWCO R W C T S_DWH R W C R W C...

Page 44: ...6 Wiring Diagram Generic Zone System with Zone Valves Zone1 T S Zone2 T S Zone3 T S Zone4 T S Zone5 T S Zone6 T S Zone1Valve Zone2Valve Zone3Valve Zone4Valve Zone5Valve Zone6Valve T T N A H DHW PRI L...

Page 45: ...CO R W C T S_DWH R W C R W C T S_CH_ZONE1 T S_ZONE2 SUPPLY TEMPERATURE SENSOR RETURN OUTDOOR T S_ZONE3 R W C N A H DHW PRI L N L N L N L N Z2 Z1 Air Handler NFC Connect the pump wires to the system pu...

Page 46: ...To control the boiler supply or return water temperature using the external temperature sensor configure the system accordingly On the front panel press the Menu button to enter the setting menu and t...

Page 47: ...f the gas meter to ensure a sufficient gas supply The boiler is recommended to be the first appliance to be connected to the gas supply line Gas meter capacity The total capacity of connected applianc...

Page 48: ...ow When using rigid pipe Navien recommends the installation of a union on the gas supply line close to the boiler to facilitate any future maintenance or service Check with the local jurisdiction to v...

Page 49: ...230 2 080 1 950 1 840 1 630 3 in 11 300 7 780 6 250 5 350 4 740 4 290 3 950 3 670 3 450 3 260 2 890 4 in 23 100 15 900 12 700 10 900 9 660 8 760 8 050 7 490 7 030 6 640 5 890 In Cubic Feet ft3 per Ho...

Page 50: ...60 3 750 3 210 2 840 2 570 2 370 2 200 2 070 1 950 1 730 1 570 1 440 4 2 Measuring the Inlet Gas Pressure WARNING The boiler cannot function properly without sufficient inlet gas pressure Measuring th...

Page 51: ...as pressure must fall within the ranges specified on page 10 To measure the inlet gas pressure 1 Shut off the manual gas valve on the gas supply line Gas Valve Opened Closed 2 Turn on the boiler On th...

Page 52: ...ipe to the Vent Collar 1 Measure 1 3 4 inches from the end of the vent pipe then draw a mark at that distance Mark 1 3 4 from the end of the pipe 1 3 4 2 Insert the pipe into the vent collar to start...

Page 53: ...o the outside of the building create an airtight seal from the boiler collar to the vent termination Intake materials can be made of ABS PVC CPVC PP galvanized or stainless steel corrugated aluminum o...

Page 54: ...m back drafting will not be covered by the Navien warranty If there is any question about the possibility of back drafting in the installation location use a direct venting system for the boiler When...

Page 55: ...ator vent outlet 36 in 91 cm J Clearance to non mechanical air supply inlet to building or the combustion air inlet to any other appliance 36 in 91 cm 48 in 120 cm below or to side of opening 12 in 30...

Page 56: ...ly Note When you set PCB DIP switch 2 8 to On ensure that CPVC polypropylene or stainless steel piping is used for exhaust venting 1 2 3 4 5 6 O N O N 1 2 3 4 5 6 7 8 CAUTION This boiler has a built i...

Page 57: ...is appliance Only terminations of the same manufacturer as the vent system must be used Refer to the vent manufacturer s instructions for detailed installation procedures and guidelines 5 3 Measuring...

Page 58: ...hichever is greater Concentric Sidewall Venting 1 25 mm min Combustion Air Combustion Air Maintain 12 300 mm min clearance above highest anticipated snow level or grade whichever is greater Vent Vent...

Page 59: ...l Residential vent pipes to connect the InnoFlue Flex 2 in vent pipes to the exhaust After installation ensure that the vent system is tightly sealed at the joints All installation using the flexible...

Page 60: ...OFF 1 stage MIN 1 OFF 2 ON 1 stage MAX 1 ON 2 ON 3 4 Reserved 5 6 Model NFC 200 5 OFF 6 OFF NFC 175 5 ON 6 OFF 6 2 Dip Switch 2 8 switch unit The DIP SW 2 on the circuit board configures the gas type...

Page 61: ...t 610 m the unit will de rate by 3 for each 1 000 ft 305 m of altitude gain For NG if you install the unit at above 5 400 ft 1 646 m it is required to change the Gas Orifice for high altitude Be caref...

Page 62: ...discard the factory installed plug Install a power switch between the breaker and the boiler to facilitate end user maintenance and servicing Connect the boiler to a 110 120V AC at 60 Hz with a maxim...

Page 63: ...ters NPE model to meet high volume heating demands Some possible connection options include the following Example of a Basic Cascade System Application Pressure Relief Valve Air Vent Main Faucet Ball...

Page 64: ...connect all the NPE A series water heaters to the recirculation line If this is the case set any unconnected A model water heaters to Internal Recirculation Mode For any NPE A water heater that is co...

Page 65: ...rculation Return Line Is Installed Connect the domestic hot water return line to the desired number of NPE A water heaters Set each unconnected NPE A water heater to Internal Recirculation Mode The NF...

Page 66: ...als for additional details The NFC boiler should be set to Combi Pre heat Mode s NPE A Pressure Relief Valve Air Vent Ball Valve Solenoid valve Pressure Relief Valve Faucet Check Valve Sub1 NPE S Sub2...

Page 67: ...ting and then select START 8 3 Connecting the Communication Cables You can connect one NFC boiler with up to 15 Navien water heaters NPE Model using the Ready Link communication cables Select the NFC...

Page 68: ...ial button when the following screen appears All the display screens on the configured water heaters will return to the temperature display Note To add additional sub water heater at a later time repe...

Page 69: ...o 7 NPE water heater units may be connected to one common vent system In a cascade system that has more than 7 NPE water heaters use 2 common vent systems or consult Navien Use only approved PVC cemen...

Page 70: ...mum Back 0 5 in 13 mm minimum Front 4 in 100 mm minimum Sides 3 in 76 mm minimum Bottom 12 in 300 mm minimum CAUTION It is necessary to leave clearance for service access Clean Debris and Chemical fre...

Page 71: ...e installing the components All vent joints must be fully tightened Before operating the system ensure that the Installed vent system is clean and free of debris Ensure that the vent system is rigidly...

Page 72: ...sting the pipe spreads the solvent cement evenly to ensure a solid joint 3 Hold the pipe and pipe fitting together for about 15 seconds until the cement sets Note Use approved solvent type cement for...

Page 73: ...mation on the required load amount and the total length for one NFC boiler with up to 7 NPE water heaters installed Required Load Total BTU H Model Total Length ft NFC 175 200 NPE 240 D 3 D 4 D 6 D 8...

Page 74: ...neighbor s phone Follow the gas supplier s instructions If you cannot reach your gas supplier call the fire departmen t Installation and service must be performed by a qualified installer service age...

Page 75: ...assemble the backflow damper on the NFC boiler unit 1 Remove the screws from the exhaust vent adapter 2 Detach the exhaust vent adapter 3 Connect the backflow damper to the exhaust duct of the boiler...

Page 76: ...start the vent run with a 90 street elbow at the vent collar Using a street elbow directly at the collar will not allow for a tight seal between the appliance and vent pipe A length of straight pipe...

Page 77: ...nstallation Manuals supplied with the boiler units 9 4 1 Connecting the Main Pipe Runs toT Joint After connecting the tee joint to the branch pipe connect the main trunk pipe to each side of the tee E...

Page 78: ...tus and Set Rotate the Command dial to switch between the parameters or to increase decrease setting values Press the Command dial to select 7 Vent Type Setting Note For more information on the vent t...

Page 79: ...ance of at least 36 with the exhaust above the intake but do not exceed 20 Intake Maximum length 20 6 m Minimum length 36 91 cm Exhaust Note The illustration is intended for reference purposes only Di...

Page 80: ...se to the cascade system and direct the end of the hose to a drain WARNING After installing the condensate drain hose check the loop again to ensure that the prime water is not spilled The loop siphon...

Page 81: ...arance to service regulator vent outlet 3 ft 91 cm J Clearance to nonmechanical air supply inlet to building or the combustion air inlet to any other appliance 36 in 91 cm 12 in 30 cm K Clearance to a...

Page 82: ...r Fix screw 2 Through the maintenance port check the operating condition of the damper plate inside the backflow damper Damper plate is OPEN Damper plate is CLOSED 3 Reinstall the gasket and maintenan...

Page 83: ...piping clear of combustible materials including clothing cleaning materials and rags Connecting the Gas Supply Yes No Does the gas supply match the type specified on the boiler s rating plate Is the g...

Page 84: ...f valve to within 6 12 in 150 300 mm of the floor Connecting the Condensate Drain Yes No Have you installed a condensate drain line from the boiler to a drain or laundry tub Venting the boiler Yes No...

Page 85: ...setting DIP SW 2 set of 8 Yes No Gas type Is switch 1 set correctly for LP ON or NG OFF If continuous boiler operation is required is switch 7 in the up ON position If high temperature venting has be...

Page 86: ...iler will operate at this set temperature Take note of the original heating temperature in case you want to restore it to the default The default space heating supply water temperature range is 104 F...

Page 87: ...er operation reset the boiler to resolve the problem Press the Back button on the front panel to reset the boiler If resetting the boiler does not solve the problem refer to the Troubleshooting sectio...

Page 88: ...e On 8bit AD values equal to or lower than 70 Flame Off 8bit AD values equal to or higher than 175 11 3 Accessing Basic Menu Items In the Main Menu screen you can view the boiler s operating condition...

Page 89: ...Panel F W Ver Controller panel firmware version 11 3 3 Setting the Space Heating Operation To set the boiler s space heating operation press the Menu button and then select 3 Space Htg Operation Rota...

Page 90: ...s 120 170 F 48 5 76 5 C 101 139 F 38 59 C 7 Custom 104 180 F 40 82 C 86 149 F 30 65 C User defined Heat loads 1 6 show the preset temperature ranges based on the load type selected while heat load 7 p...

Page 91: ...combi pre heat the space heating will take priority Press the Back button to return to the previous screen or menu Item Description 1 DHW Set Temp Set the hot water temperature F Setting range 86 140...

Page 92: ...to the Schedule menu Working Not working Rotate the Command Dial to choose the scheduled time You can choose the time in 30 minutes intervals To finalize the weekly schedule settings press and hold t...

Page 93: ...ry press the Menu button and then select 5 Error History A list of 10 recent errors are displayed on the screen with the most recent error displayed at the top of the list Rotate the Command dial to s...

Page 94: ...Times Number of tenth ignition attempts 8 T Limit No of times Number of times supply return temperature limit control has activated 9 Supply Limit No of times Number of times Recirculation supply temp...

Page 95: ...utton and the Menu button simultaneously for 3 seconds and then select 2 Input Output Status Rotate the Command dial to switch between the information items Press the Command dial to select an item an...

Page 96: ...tem water pressure Setting range 40 80 psi Default 50 psi After entering the parameter setting screen rotate the Command dial to switch between the parameters or to increase decrease setting values Pr...

Page 97: ...the Menu button simultaneously for 3 seconds and then select 4 Cascade Status and Set Rotate the Command dial to switch between the parameters or to increase decrease setting values Press the Command...

Page 98: ...ized The boilers whose IDs are initialized by the Main are set to Sub setting mode if you press the OK button for 2 seconds or more the Main gives you the ID and it is displayed on the screen The Main...

Page 99: ...operation On Off Off On This option is available only when the Zone Pump System is active 5 Zone 3 Pump Test the Zone 3 pump operation The Zone 3 pump is turned on as soon as you enter the test mode...

Page 100: ...k button and the Menu button simultaneously for 3 seconds and then select 7 Special Operations Rotate the Command dial to switch between the operation modes Press the Command dial to select an operati...

Page 101: ...upply thermistor open or short circuit Contact technical support at 1 800 519 8794 E218 Heating return thermistor open or short circuit Contact technical support at 1 800 519 8794 E278 Abnormal operat...

Page 102: ...mperature sensor wiring connection E761 Abnormal operation Pre Heat Aquastat Check the Pre Heat Aquastat wiring connection Select an option other than Aquastat mode E777 LWCO service code 7700 externa...

Page 103: ...corporation or company which either in person or through a representative is engaged in and is responsible for the connection utilization repair or servicing of gas utilization equipment or accessori...

Page 104: ...ge 4 With the internal components exposed locate the gas inlet pipe and the gas valve as shown in Figure 2 Gas Valve Gas Inlet Pipe Figure 2 NFC Series Internal Components 5 Remove the clip at locatio...

Page 105: ...T adjust or attempt to measure gas valve outlet pressure The gas valve is factory set for the correct outlet pressure This setting is suitable for natural gas and propane requiring no field adjustment...

Page 106: ...ve Note This unit may be installed at elevations up to 10 100 ft 3 078 m for use with natural gas and propane To use the unit at a specific altitude the DIP Switches should be set as described above H...

Page 107: ...cuit board configures the operation status and model capacity settings 1 2 3 4 5 6 O N O N 1 2 3 4 5 6 7 8 Switch Function Setting 1 2 Operation Status Normal Operation 1 OFF 2 OFF 2 stage MAX 1 ON 2...

Page 108: ...page 100 Measure the CO2 value at low fire If the CO2 value is not within 0 5 of the value listed in Table 2 the gas valve set screw will need to be adjusted If adjustment is necessary locate the set...

Page 109: ...ersion Kit No NAC NCH200 Inlet Gas Pressure Pression d entr e du gaz Min 8 0 to Max 13 0 in WC Figure 10 Proper Placement of Gas Conversion Labels Note The gas conversion rating plate varies depending...

Page 110: ...O AC 24V 60Hz LWCO AC24V LWCO 1 T S4 T S3 T S2 External Recirculation THERMOSTAT1 THERMOSTAT2 CNC4 CNC5 CNC6 1 CNK1 CND1 FUSE 250V 3 15A 3WAY V V CNV1 1 CNX1 THERMOSTAT T S1 CNC1 1 THERMOSTAT3 CNC2 1...

Page 111: ...I FILTER DC5V H T L_1 WD PSS SMPS Primary Secondary 3 15A System Return Thermistor Relay 4 Outdoor Thermistor INLET Thermistor Dip Switch Air Handler Output Dip Switch Relay 3 Relay 2 Relay 5 Relay 5...

Page 112: ...th no splices except at the unit harness connection with blue leader wire Caution should be taken to avoid potential electromagnetic interference EMI by routing separately from potential sources such...

Page 113: ...automatically changes according to the outdoor temperature and the current space heating system application system load You can configure the Outdoor Reset Control settings on the front panel Refer t...

Page 114: ...114 Appendixes 12 6 Component Assembly Diagrams and Parts Lists 12 6 1 Case Assembly 1 2 3 5 10 14 8 9 11 12 13 21 22 23 16 17 18 20 19 19 7 6 4 15...

Page 115: ...Assembly 30008662B 9 Intake Air Filter 30016248B 10 Base Packing 20041078A 11 Air Vent Adapter 20045716A 12 Screw M4X14L 20038754A 13 Rubber Ring 20029318A 14 Exhaust Duct Assembly 30008673A 15 24V Po...

Page 116: ...116 Appendixes 12 6 2 Heat Exchanger and Waterway Assembly 1 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 18 21 2 4 8 21 3 21 24 6 21 20 27 28 29 30 31...

Page 117: ...042823A 13 Exhaust Duct Clip 20042741A 14 Exhaust Duct Cap 20029712A 15 Thermistor Exhaust 30020489A 16 Exhaust Duct Packing Upper 20024690A 17 Screw M4X6L 20006535A 18 Screw M4X20L 20042814A 19 Air P...

Page 118: ...118 Appendixes 12 6 3 Combustion Parts Assembly 30 24 26 25 23 22 21 20 18 16 15 29 14 1 2 3 4 5 6 38 34 27 28 37 11 9 10 8 36 13 31 12 9 36 9 35 7 19 17 33 34 35 32 39 34 40 41...

Page 119: ...king 20045644A 20 Flame inspection window Upper 20040231A 21 Flame inspection window Lower 20040232A 22 Flame inspection window Graphite Packing 20043399B 23 Flame inspection window Glass 20040236A 24...

Page 120: ...28 26 25 45 46 47 48 50 51 52 53 8 45 49 13 Description Part Remark 1 Plate Heat Exchanger 30021098A 2 DHW Connection Adapter 30021869A 3 Mixing Valve Adapter 20044471A 4 Flow Adjust Valve 30008247A 5...

Page 121: ...te 20044475A 30 DHW Inlet Adapter 20044701A 31 Fastener 27 20017726A 32 Screw M4 12 20041461A 33 Screw M4 10 20038757A 34 Block Plate Packing 20045394A 35 DHW Inlet Adapter Packing 20045393A 36 DHW Ou...

Page 122: ...Memo...

Page 123: ...Memo...

Page 124: ...tact a licensed professional for the affected system for example a plumber or electrician When you contact Technical Support please have the following information at hand Model number Serial number Da...

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