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WARNING

Never run cold water into a hot, empty boiler.

DIFFERENTIAL PRESSURE SWITCHES

The  diaphragm  type  differential  pressure  switches 

are connected by vinyl tubing to the gas valve and 

the air inlet connection on the negative side and the 

sight glass adapter on the positive side. The pres-

sure switches monitor air flow by sensing the differ-

ential pressure measured in inches of water (” w.c.). 

The factory settings on these switches are 0.5” w.c. 

on the normally open switch and 3.5” w.c. for the nor-

mally closed switch. See Section XVI, 

“Detailed Se-

quence of Operation,” 

for details on the operation of 

the differential pressure switches.

BLOWER 

The blower provides a means for pushing combus-

tion air into and through the mixer, the burner, the flue 

ways of the cast aluminum boiler section before being 

discharged through the vent piping to the outdoors. 

 

CIRCULATOR PUMP

Every forced hot water system requires at least one 

circulating pump. The circulating pump imparts the 

necessary  energy  to  move  the  water  through  the 

closed  loop  supply  and  return  piping  systems,  ter-

minal heating equipment (finned tube radiators, etc.) 

and back through the boiler for reheating. To provide 

the required hot water flow rates, the circulator pump 

must be properly sized to overcome frictional losses 

(usually measured in feet of water, also referred to 

as “pump head loss”) of the supply and return piping 

systems and boiler. The circulator pump is furnished 

in a carton within the boiler cabinet. The circulator(s) 

should always be located on the downstream (i.e., 

“pumping away”) side of the expansion tank.

DRAIN VALVE

The manual drain valve provides a means of draining 

the water in the heating system, including the boiler 

and hot water supply and return piping systems in-

stalled above the drain valve. This drain valve is in-

stalled in the ¾” tapping at the bottom of the boiler. 

Any piping installed below the elevation of this drain 

valve  will  require  additional  drain  valves  to  be  in-

stalled at low points in the piping systems in order to 

drain the entire system.  

A.S.M.E. RATED PRESSURE RELIEF VALVE

Each boiler must have a properly sized and installed 

A.S.M.E. rated pressure relief valve. Water expands 

as it is heated by the burner/boiler sections. If there 

is no place for the water to expand its volume, (i.e., a 

properly sized and functioning expansion tank) pres-

sure on the inside of the boiler and heating system 

will increase. The furnished relief valve will automati-

cally open at 30 psig pressure to relieve the strain 

on the boiler and heating system from the increasing 

pressure. The pressure relief valve discharge must 

be piped with the same size as the valve discharge 

opening to an open drain, tub or sink, or other suitable 

drainage point not subject to freezing, in accordance 

with A.S.M.E.  specifications.  Failure  to  provide  the 

pressure relief valve with piping as herein described 

may cause water damage and/or serious bodily in-

jury. The boiler manufacturer is not responsible for 

any water damage or personal injury.

 BLOCKED VENT SAFETY SHUTOFF

The  boiler  is  equipped  with  a  blocked  vent  safety 

shutoff  which  shuts  off  the  main  burner  gas  in  the 

event that the airflow of combustion products through 

the  flue-way  is  reduced.  In  the  event  of  a  blocked 

flue-way, enough air will not be available to support 

combustion and the IBC will lock out due to loss of 

adequate air flow. Pressure switches monitor air flow 

by  sensing  differential  pressure.  The  contacts  are 

normally open and close when the draft inducer is 

running and causing the differential pressure at the 

switch to exceed its setting. The closed switch proves 

there is adequate air flow for combustion. The pres-

sure switch shuts off the main burner if the differential 

pressure is inadequate due to a blocked vent pipe, 

a blocked air intake, a blocked boiler section, or a 

blocked air inducer. After 5 minutes of inadequate dif-

ferential pressure, the IBC will lock out. The “Purge” 

indicator  lamp  (see  Figure  16)  will  blink,  indicating 

a  failure  to  prove  adequate  combustion  air  flow  or 

flue gas flow. The IBC will automatically reset after 

15 minutes or can be manually reset as noted in the 

section titled 

“Hot Surface Igniter.”

 If the boiler cannot 

be restored to normal operating condition by reset-

ting the control, contact a qualified service agency to 

check the heat exchanger flue-ways for blockage.

LOW WATER CUT OFF

This unit is equipped with a low water cut off control 

that protects against dry firing. This control provides 

burner cut off if there is an unsafe water loss, which 

can result from a broken or leaking radiator, pipe, or 

boiler. A water/glycol mixture up to 50% concentra-

tion may be used with the low water cut off.

 

EXTERNAL CONDENSATE PUMP (OPTIONAL)

For installations where there is no floor drain or other 

appropriate  drainage  available  to  receive  conden-

Summary of Contents for UB90 125

Page 1: ...RED DIRECT VENT CONDENSING HOT WATER BOILER P N 240004826U Rev 1 3 01 06 An ISO 9001 2000 Certified Company UTICA BOILERS P O Box 4729 Utica NY 13504 4729 www uticaboilers com INSTALLATION MANUAL AND OPERATING INSTRUCTIONS ...

Page 2: ... low flame temperature means drastically reduced CO and NOx emissions which contribute to a cleaner and healthier environment This appliance unlike normal residential atmospheric and induced draft units takes its combustion air directly from the outdoors sealed combustion and does not compete with building occupants for fresh air Sealed combustion also known as direct vent is the safest and best wa...

Page 3: ...nce of these codes use NFPA installation codes and good industry practice 2 Before servicing the boiler allow it to cool Always shut off any electricity and gas supply connected to the boiler prior to servicing 3 Inspect gas line for leaks 4 Be certain gas input rate is correct Overfiring mayresultinearlyfailureoftheboilercomponents Thismaycausedangerousoperation Underfiring may result in too much a...

Page 4: ... 900 195 750 171 900 171 200 146 900 146 700 123 050 122 250 2 000 191 800 191 500 168 800 167 400 143 800 143 400 121 100 119 500 3 000 187 700 187 250 165 700 163 600 140 700 140 100 119 150 116 750 4 000 183 600 183 000 162 600 159 800 137 600 136 800 117 200 114 000 5 000 179 500 178 750 159 500 156 000 134 500 133 500 115 250 111 250 6 000 175 400 174 500 156 400 152 200 131 400 130 200 113 3...

Page 5: ...E BOILER Complete all of the following prior to installing the boiler CODES This boiler product is a gas fired direct vent con densing boiler and must be installed in accordance with all applicable federal state and local building codes including but not limited to the following United States Installation shall conform with National Fuel Gas Code NFPA 54 ANSI Z223 1 latest revision Canada Installat...

Page 6: ...n a location which facilitates the operation of venting and combustion air intake piping systems as de scribed in this manual 6 Advise owner of boiler to keep venting and combustion air intake passages free of obstruc tions Both the venting and combustion air intake piping systems connected to the outdoors must permit flow through the piping systems without restrictions for the boiler to operate 7 ...

Page 7: ...irtight and watertight Combustion air and vent piping must also terminate exactly as shown in Figures 1 2 If a concentric vent termination is being used refer to Figures 3 5 for proper setup Vent connections serving appliances vented bynaturaldraftshallnotbeconnectedintoany portionofmechanicaldraftsystemsoperating under positive pressure Solventcementsarecombustible Keepaway from heat sparks or op...

Page 8: ...nd all doors between the space in which the appliances remaining connected to the common venting system are located and oth er spaces of the building Turn on clothes dryer and any appliance not connected to the common venting system Turn on any exhaust fans such as range hoods and bathroom exhaust so they will operate at maximum speed Do not operate a summer exhaust fan Close fire dampers 4 Place i...

Page 9: ...ler make sure that clean water sup ply is available When the water supply is from a well or pump a sand strainer should be installed at the pump PRESSURE RELIEF VALVE TEMPERATURE PRESSURE GAUGE The boiler is furnished with a relief valve and tem perature pressure gauge in the boiler parts bag In stall vent relief valve as shown in Figure 7 Provide piping from the relief valve to a local floor drain...

Page 10: ...d if floor drain is not available The condensate pump must be designed for flue gas condensate application Figure 9b MULTIZONE BOILER PIPING WITH ZONE VALVES NOTE When zoning with circulators the furnished circulator pump should be used as one of the zone pumps Each stripped end of the electrical wires for the circulator pump inside the junction box should be taped or wire nutted to prevent short ci...

Page 11: ... or applicable provisions of the local building code These boilers require a dedicated direct vent sys tem All air for combustion is taken directly from outdoors through the combustion air intake pipe All flue products are discharged to the outdoors through the vent pipe 1 See Figures 1 2 in Section V Combustion Air and Vent Pipe Requirements for standard two pipe roof and sidewall terminations and...

Page 12: ...Comply with all clearances required as stated in paragraph 6 below Termination should be positioned where vent vapors will not damage plants shrubs air conditioning equipment or siding on the house Termination should be positioned so that it will not be effected by wind eddy air born leaves snow or recirculated flue gases Termination should be positioned where it will not be subjected to potential ...

Page 13: ... cement in light uniform coat on the inside of socket to prevent buildup of excess cement Apply second coat 8 While cement is still wet insert pipe into sock et with a turn twist Be sure pipe is fully in serted into fitting socket 9 Wipe excess cement from joint A continuous bead of cement will be visible around perimeter of a properly made joint 10 Handle pipe joint carefully until cement sets 11 ...

Page 14: ... the National Fuel Gas Code ANSI Z223 1 latest revision In Canada follow the CAN CGA B149 1 and 2 Installation Codes for Gas Burning Appliances and Equipment 2 Use pipe joint compound suitable for liquefied petroleum gas on male threads only 3 Use ground joint unions 4 Install a sediment trap upstream of gas con trols 5 Use two pipe wrenches when making the con nection to the gas valve to keep it f...

Page 15: ...aving jurisdiction or in the absence of such requirements with the National Electrical Code ANSI NFPA 70 latest revision In Canada electrical wiring shall comply with the Canadian Electrical Codes CSA C22 1 and 2 Run a 14 gauge or heavier copper wire from the boiler to a grounded connection in the service pan el or a properly driven and electrically grounded ground rod INSTALLING THE THERMOSTAT Th...

Page 16: ...ATIC WIRING CONNECTIONS NOTE If any of the original wire as supplied with this appliance must be replaced it must be replaced with type 150 C Thermoplastic wire or its equivalent Figure 14 LADDER WIRING DIAGRAM ...

Page 17: ...nostic indicator lamps see Figure 16 will blink indicating the failure mode as a lack of flame signal The IBC is manually reset from lockout by either removing and reestablishing the thermostat s call for heat or by turning the ser vice switch off then back on HIGH LIMIT AQUASTAT CONTROL The high limit aquastat control determines the maxi mum boiler water temperature and also provides a means for p...

Page 18: ...and functioning expansion tank pres sure on the inside of the boiler and heating system will increase The furnished relief valve will automati cally open at 30 psig pressure to relieve the strain on the boiler and heating system from the increasing pressure The pressure relief valve discharge must be piped with the same size as the valve discharge opening to an open drain tub or sink or other suit...

Page 19: ...ibility of their product with aluminum c Follow the antifreeze manufacturer s in structions on determining proper ratio of an tifreeze to water for the expected low tem perature conditions and for maintaining the quality of the antifreeze solution from year to year Improperly maintained antifreeze solu tions will gradually lose their ability to protect the aluminum boiler from corrosion d The reco...

Page 20: ...eration 5 Inspect piping system Repair any leaks im mediately FILLING BOILER WITH WATER AND PURGING AIR FOR SYSTEMS WITH CONVENTIONAL CLOSED TYPE EXPANSION TANKS Refer to the appropriate diagrams in Section VII Near Boiler Piping for more information 1 Close all zone service valves on the supply and return piping and close the expansion tank service valve Drain expansion tank Open the feed valve a...

Page 21: ...ve a pilot It is equipped with an ignition device which automat ically lights the burner Do NOT try to light this burner by hand 5 Remove the front jacket panel 6 Turn off the gas shut off valve Valve handle should be perpendicular to the gas pipe 7 Wait five minutes for any gas to clear Then smell for gas including near the floor If you smell gas STOP Follow instructions at left un der What To Do I...

Page 22: ...s Supply Piping in this manual 3 Check for orifice in negative pressure hose at gas valve and 2 air intake pipe upstream of gas valve 4 Relight boiler 5 If boiler still does not light the air inlet pipe may need to be disconnected to allow the boiler to start in order to verify the boiler firing rate and combustion properties The inlet air pipe can be disconnected by removing the PVC inlet air pipin...

Page 23: ...power is being delivered to the hot surface igniter for the 20 second igniter warm up period The bright yellow orange glow of the hot surface igniter can be observed through the observation port on the boiler A B C D E 6 After the igniter warm up period the integrated boiler control energizes the gas valve initiating a 6 second trial for ignition mode which is indicated by the illumination of Lamp...

Page 24: ...al reset high limit or additional safety controls test for operation as outlined by the control manu facturer Burner should be operating and should go off when controls are tested When safety controls are restored burner should reignite SET THERMOSTAT HEAT ANTICIPATOR IF USED AND VERIFY THERMOSTAT OPERATION For a single thermostat connected to the yellow thermostat lead wires in the furnished field...

Page 25: ...y into the exhaust gas stream Take a flue gas reading and observe the CO2 value Adjust the throttle screw until the CO2 value is between 8 5 and 10 Turning the throttle screw counter clockwise increases the rate and the CO2 value Turning the throttle screw clockwise decreases the rate and the CO2 value Allow the appliance to sta bilize for approximately 1 minute after adjusting the throttle screw b...

Page 26: ...nts for leakage and tighten bolts or replace gaskets if necessary h Remove jacket front and top panels and check for piping leaks around relief valve and other fit tings Repair if found DO NOT use stop leak compounds 2 Check that boiler area is free from combustible materials gasoline and other flammable vapors and liquids 3 Circulator pump and blower motor furnished with boiler are permanently lubr...

Page 27: ...d away with spraying or run ning water i Use a flexible handle nylon brush to loosen sediment and aluminum oxide on all exposed heating surfaces of boiler see Repair Parts Manual for diagram Be sure that brush does not get stuck in heat exhanger j After brushing and rinsing remove any remain ing loosened sediment using a shop vacuum with a snorkel attachment k Inspect burner for any foreign matter ...

Page 28: ... FOR 20 SEC IGNITER WARMUP BRIGHT YELLOW ORANGE GLOW OF THE HOT SURFACE IGNITER CAN BE OBSERVED THRU THE OBSERVATION PORT IN FRONT OF BOILER SECTION JUST ABOVE IGNITER IGNITOR LIGHT IS ON GAS VALVE ENERGIZED THRU 3K1 AND 4K1 CONTACTS VALVE LIGHT IS ON GAS VALVE OPENS FOR 6 SEC TRIAL FOR IGNITION BLUE ORANGE GLOW OF THE BURNER CAN BE SEEN THRU OBSERVATION PORT 2 SEC INTO THE 6 SEC IGNITION TRIAL PO...

Page 29: ...RAFT INDUCER RUNS THROUGH 30 SECOND POST PURGE CONTROL WILL ATTEMPT TO RELIGHT BOILER 3 TIMES IF FLAME IS NOT PROVEN CONTROL LOCKOUT PROBLEM ESTABLISHING A FLAME SIGNAL VALVE LIGHT IS BLINKING CONTROL WILL AUTOMATICALLY RESET AFTER 1 HOUR HIGH LIMIT CONTROL IF BOILER WATER TEMPERATURE REACHES HIGH LIMIT AQUASTAT SETPOINT HIGH LIMIT N C CONTACTS OPEN IMMEDIATELY CLOSING GAS VALVE VALVE AND FLAME LI...

Page 30: ...ION THERMOSTAT ENDS CALL FOR HEAT GAS VALVE AND CIRCULATOR PUMP ARE DE ENER GIZED VALVE AND FLAME LIGHTS GO OUT BLOWER RUNS FOR 30 SECONDS POST PURGE PURGE LIGHT IS ON BLOWER IS DE ENERGIZED AFTER 30 SECONDS PURGE LIGHT SHUTS OFF BOILER STAND BY FOR NEXT CALL FOR HEAT ...

Page 31: ...remely unlikely that two consecutive controls are defective If it seems to be hap pening chances are that either there is nothing wrong with the control or it is being damaged by some other problem for example an electrical short burning out a transformer INITIAL SERVICE CHECKS 1 Before troubleshooting a Make sure that circuit breaker is on or fuse is okay ay electrical panel b Make sure that serv...

Page 32: ...kage in air intake or vent pipes Undersized air intake or vent pipes Loose blower wheel on motor shaft Incorrect pressure switch or pres sure switch setpoint Gas valve out of adjustment 6 When pressure reading is proper and the pressure switch is operating prop erly remove testing lines and reinstall vinyl caps to Tee and 3 way connector Boiler Status Differential Pressure Switch Contacts Not Runn...

Page 33: ... occurs If this table does not readily provide the reason for boiler malfunction or non operation refer to the following pages for more detailed troubleshooting procedures WARNING ELECTRICAL SHOCK HAZARD MAY CAUSE SERIOUS INJURY OR DEATH The following procedures may expose you to dangerous line voltage Use caution to avoid touching live electrical contacts Service must be performed by a trained ex...

Page 34: ...34 TROUBLESHOOTING TROUBLESHOOTING CHART 1 ...

Page 35: ...35 TROUBLESHOOTING TROUBLESHOOTING CHART 2 ...

Page 36: ...E CONDENSATE MAY PUDDLE AND BLOCK THE VENT YES CHECK AIR PRESSURE SWITCH PER INSTRUCTIONS ON FOLLOWING PAGES ARE SAMPLING LINES CLEAR AND CONNECTED PROPERLY NO CLEAN OUT SAMPLING LINES OR REPLACE DEFECTIVE SWITCH YES CHECK FLUE PASSAGES IN BOILER PER MAINTENACE AND CLEANING ARE FLUE PASSAGES IN BOILER CLEAN NO CLEAN BOILER FLUE PASSAGES PER MAINTENANCE AND CLEANING INSTRUCTIONS YES CHECK DRAFT IND...

Page 37: ...F DOES MAIN BURNER LIGHT CHECK FOR 24 VAC ACROSS TERMINALS MV ON THE GAS CONTROL WHILE VALVE FLAME INDICATOR LIGHT IS ON NO NO CHECK FOR 24 VAC ACROSS TERMINALS CN6 2 AND CN6 5 ON IBC WHILE THE VALVE FLAME LED IS LIT NO REPLACE IBC YES REPAIR REPLACE WIRING BETWEEN IBC AND GAS CONTROL YES CHECK IF IGNITER SENSOR POSITION IS OK TIP SHOULD BE SLANTED TOWARDS BURNER RESTORE IGNITER SENSOR TO CORRECT ...

Page 38: ...38 TROUBLESHOOTING TROUBLESHOOTING CHART 5 ...

Page 39: ...R MFGR FOR SPECIFIC INSTRUCTIONS REQUIRES SPECIFIC TOOLS NO YES REPLACE BURNER REPLACE IBC BOILER SHUTS OFF BEFORE END OF CALL FOR HEAT ARE HI LIMIT AQUASTAT CONTACTS CLOSED NO BOILER OFF ON HIGH LIMIT IS ACTUAL BOILER WATER TEMP GREATER THAN HI LIMIT SET POINT MINUS 30 F CONTROL DIFFERENTIAL NO NO REPLACE AQUASTAT OK YES SEE TROUBLESHOOTING PATH 2 ABOVE CHART 5 NO 3 CHART 5 YES SET THERMOSTAT BEL...

Page 40: ...ce issues reviewed with owner maintenance person o Installation booklet affixed on or adjacent to boiler Installer Company __________________________________________________________ Address ___________________________________________________________________ Phone _____________________________________________________________________ Installer s Name___________________________________________________...

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