Laars HWG-M2-250 Service Manual
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Laars HWG-M2-250 Service Manual

Laars HWG-M2-250 Service Manual

Hwg-m2 series, cb-m2 series, hot water generator for natural or propane gas, condensing boiler for natural or propane gas
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Service Manual
Service Manual for
9600 CB & HWG
HWG-M2 Series
HWG-M2-250
HWG-M2-200
HWG-M2-175
HWG-M2-150
Hot Water Generator
For Natural or
Propane Gas
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualified in hot water boiler installation and maintenance. Improper installation and/or operation could
create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death.
Improper installation and/or operation will void the warranty.
If the information in this manual is not followed exactly, a fire or explosion may result
causing property damage, personal injury or loss of life.
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or
any other appliance.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a nearby phone. Follow the gas supplier's
instructions.
• If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency, or gas
supplier.
CB-M2 Series
CB-M2-250
CB-M2-200
CB-M2-175
CB-M2-150
Condensing Boiler
For Natural or
Propane Gas
WARNING
WHAT TO DO IF YOU SMELL GAS
Document 2109

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Summary of Contents for Laars HWG-M2-250

  • Page 1 Service Manual Document 2109 Service Manual for 9600 CB & HWG HWG-M2 Series CB-M2 Series HWG-M2-250 CB-M2-250 HWG-M2-200 CB-M2-200 HWG-M2-175 CB-M2-175 HWG-M2-150 CB-M2-150 Hot Water Generator Condensing Boiler For Natural or For Natural or Propane Gas Propane Gas FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician, qualified in hot water boiler installation and maintenance.

  • Page 2: Table Of Contents

    LAARS Heating Systems Page 2 TABLE OF CONTENTS Operating Control ........11 SECTION 1. Vent TCO ............ 12 General Information Intake TCO ..........12 Introduction ........... 3 Thermal Cut-Out (TCO) ........ 12 Start Up Procedures ........9 Delayed Ignition ........... 12 Checkout Procedures ........

  • Page 3: General Information

    9600 CB & HWG Service Manual Page 3 primary H-X back to its inlet so that the primary H-X SECTION 1. temperature is always maintained above the General Information condensation temperature of the water vapor in the flue gases. A circulator is built into the unit to provide enough head to circulate water through the H-X’s and 1A.
  • Page 4 LAARS Heating Systems Page 4 THERMOSTATIC A PORTION OF DIVERTING HOT WATER VALVE IS RECYCLED TO MAINTAIN (160° F THERMOSTAT) COMBUSTION COIL INLET TEMPERATURE AT 140°F COMBUSTION COIL ECONOMIZER (A) Cold Water Inlet From Tank or System (B) Economizer Outlet (10°F Rise above inlet) (C) Combustion Coil Inlet 130-140°F Typical...
  • Page 5 9600 CB & HWG Service Manual Page 5 Legend 1 Mixing Valve 2 Internal Pump 3 Mixer Tube 4 Flue Outlet 5 Combustion Fan 6 Air Pressure Switch 7 Burner 8 Secondary Heat Exchanger 9 Primary Heat Exchanger 10 Return (From Primary Loop) 11 Gas Valve 12 Flow (To Primary Loop) A Secondary Heat Exchanger Inlet...
  • Page 6 LAARS Heating Systems Page 6 EXHAUST INTAKE TERMINAL WALL PLATE EXHAUST TERMINAL INTAKE WALL PLATE ORIFICE ORIFICE COMBUSTION COIL ECONOMIZER FLAMEHOLDER EXHAUST ASSEMBLY CONDENSATE REFERENCE PAGE 8 FOR PART NUMBERS Figure 3. Air/Fuel Flow Through Heatmaker 9600.
  • Page 7 9600 CB & HWG Service Manual Page 7 Figure 4. Cut Away View of Heatmaker 9600. Figure 5. Control Box.
  • Page 8 LAARS Heating Systems Page 8 HIGH LIMIT SAFETY SWITCH BOX BLOWER OPERATING LIMIT ASSEMBLY CIRCULATOR PUMP BLOCKED CONTROL BOX FLUE SUB-ASSY DETECTOR IGNITER ASSY HEATMAKER GAS VALVE 9600 VENT THERMAL CUT OUT INTAKE THERMAL CUT OUT THERMAL CUT OUT Figure 6. Control Components...

  • Page 9: Start Up Procedures

    9600 CB & HWG Service Manual Page 9 1B. Start Up Procedures EXHAUST Make sure that the system is properly filled, com- TERMINAL pletely purged of air and system valves are open. COMBUSTION Open system gas cock(s) and gas control knob on TESTER gas valve (if closed).

  • Page 10: Cleaning The Combustion Chamber Coil

    LAARS Heating Systems Page 10 After the heat exchanger is clean, remove the vacuum cleaner from the outer shroud flue outlet and stop vacuum cleaner. COMBUSTION COIL Carefully inspect the seal between the outer MANIFOLDS shroud and the upper head and the joint in the outer ECONOMIZER shroud.

  • Page 11: Stack Switch

    9600 CB & HWG Service Manual Page 11 power and unplug the power wires from the blower 1H. Stack Switch motor. Disconnect intake exhaust vents and remove top The Stack Switch is a normally open single pole jacket. Remove the six bolts and nuts from the blower switch which is operated by the pressure difference discharge flange and the four nuts from the blower across the air orifice.

  • Page 12: Vent Tco

    LAARS Heating Systems Page 12 gallon of water from it. Turn off electrical power and located above the gas inlet port on the gas valve. The disconnect wires from operating control. Remove gas supply to the boiler must be shut off before making operating control from diverting valve body and this connection.

  • Page 13: Short Cycling

    9600 CB & HWG Service Manual Page 13 Boiling noises can occur because of air in the the flame signal is sensed on the restart then the secondary loop of a heating system (9600 CB burner will operate again. The intermittent sending and applications) or because of pump failures in either the losing of the flame signal by the boiler control causes it 9600 CB or 9600 HWG.

  • Page 14: Routine De-Liming Procedure

    LAARS Heating Systems Page 14 will require resetting. If a lockout occurs for any of the Shut off pump and disconnect from hose. reasons stated in this section the “VALVE/FLAME” Carefully drain solution from hoses and connect light on the boiler control will flash.

  • Page 15: Troubleshooting

    9600 CB & HWG Service Manual Page 15 Note: If the stack switch contacts are closed for SECTION 2. any reason when the blower isn’t operating, a sequence Troubleshooting will not occur and after 45 seconds the control will (Detailed Flow Charts on Page 16-22) “lock out”...
  • Page 16 LAARS Heating Systems Page 16 GENERAL TROUBLE SHOOTING RESET BOILER CONTROL BY SWITCHING OFF POWER AT SIDE OF UNIT FOR 15 SECONDS 1. IS SERVICE SWITCH ON? GREEN LIGHT COMES ON 2. IS CIRCUIT ON? 3. ARE FUSES OR CIRCUIT...
  • Page 17 9600 CB & HWG Service Manual Page 17 TESTING LIMIT CIRCUIT (YOU MUST COMPLETE PAGE 16 FIRST) 1. SWITCH BOILER OFF 2. UNPLUG 9 PIN "CONTROL" PLUG 3. CHECK FOR CONTINUITY AT BACK OF "CONTROL" "CONTROL" PLUG BETWEEN RED WIRES (BOILER TEMP BELOW 170F) CONTINUITY NO CONTINUITY...
  • Page 18 LAARS Heating Systems Page 18 RED "PURGE" LIGHT FLASHING (YOU MUST COMPLETE PAGE 16 FIRST) RESET BOILER CONTROL BY SWITCHING POWER OF FOR 15 SECONDS AND THEN ON AGAIN WITH A CALL FOR HEAT / HOT WATER AFTER APPROX. TWO...
  • Page 19 9600 CB & HWG Service Manual Page 19 CHECKING STACK SWITCH (YOU MUST COMPLETE PAGE 16 FIRST) 1. SWITCH OFF BOILER SWITCH 2. REMOVE BOTH TUBES FROM STACK SWITCH AND DISCONNECT ELECTRICAL WIRES 3. CHECK FOR CONTINUITY ACROSS SWITCH TERMINALS NO CONTINUITY CONTINUITY OHMS)
  • Page 20 LAARS Heating Systems Page 20 CHECKING BLOWER (YOU MUST COMPLETE PAGE 16 FIRST) WITH A CALL FOR HEAT RESET BOILER CONTROL BY SWITCHING OFF BOILER SWITCH FOR 15 SECS. AFTER TWO SECONDS GREEN POWER LIGHT COMES ON. BLOWER STARTS REFER TO GENERAL TROUBLE SHOOTING SECTION PAGE 16 CONNECT MANOMETER TO "PRESSURE TAP"...
  • Page 21 9600 CB & HWG Service Manual Page 21 RED "VALVE/FLAME" LIGHT FLASHING (YOU MUST COMPLETE PAGE 16 FIRST) ARE GAS VALVES AND GAS METER TURNED ON. IS THERE GAS IN LP TANK (LP UNITS). RESET BOILER BY SWITCHING POWER OFF FOR TURN ON VALVES, FILL LP TANK ON LP UNIT 15 SECONDS - WHEN "VALVE/FLAME"...
  • Page 22 LAARS Heating Systems Page 22 CHECKING INTERNAL PUMP (YOU MUST COMPLETE PAGE 16 FIRST) SWITCH POWER ON, GREEN POWER LIGHT LIGHTS SEE TROUBLE SHOOTING CALL FOR HEAT EXISTS CHART PAGE 16 (THERE IS 24 VOLTS ON PINS #7 & #9 ON...
  • Page 23 9600 CB & HWG Service Manual Page 23 Figure 9. 9600 Ladder Diagram. Figure 10. 9600 Wiring Diagram. Caution Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing!
  • Page 24 (Customer Service, Service Advisors) 20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax 603.335.3355 (Applications Engineering) 1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax 905.366.0130 www.Laars.com Litho in U.S.A. © Laars Heating Systems 0810 Document 2109...

This manual is also suitable for:

Hwg-m2-200Hwg-m2-175Hwg-m2-150Cb-m2-250Cb-m2-200Cb-m2-175 ... Show all

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