Lochinvar 90, 500 Venting of Combination Gas Valves, Two Stage Burner Control System

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3Gas connections (continued)

Combination Gas Valves

Installation & Service Manual

PRESSURE REGULATOR ADJUSTMENT (UNDER CAP SCREW)

INLET PRESSURE TAP

OUTLET

PRESSURE TAP

PILOT OUTLET

Each unit has a combination gas valve(s) to control the gas supply to the burners. The 500,000 Btu/hr model has two combination gas valves to supply gas to the burners. The combination valve consists of a gas regulator and two valve seats to meet the requirements for redundant gas valves. The valve has a gas control knob that must remain in the open position at all times when the appliance is in service. Each gas valve has pressure taps located on the inlet and outlet sides. Manifold pressure is adjusted using the regulator located on the valve. The

RED RESET BUTTON				GAS CONTROL KNOB

Figure 3-5_F1 Gas Valve, standing pilot

manifold pressure is preset at the factory and adjustment is not usually required. If the manifold pressure is to be adjusted, follow the “Gas Manifold Pressure Adjustment Procedure”, page 21 for proper adjustment.

Venting of Combination Gas Valves

PRESSURE REGULATOR
ADJUSTMENT (UNDER CAP SCREW)	WIRING TERMINALS

INLET PRESSURE TAP

OUTLET

PRESSURE TAP

PILOT OUTLET

The combination gas valve regulator used on all models is equipped with an integral vent limiting orifice. The vent limiter ensures that the volume of gas emitted from the valve does not exceed the maximum safe leakage rate allowed by agency requirements. Combination gas valve/regulators equipped with integral vent limiters are not required to have vent or relief lines piped to the outdoors. A dust cap is provided at the vent termination point on the valve to prevent blockage of the vent limiter

GAS CONTROL KNOB

Figure 3-6_F9 Gas Valve, spark ignition

by foreign material. The combination gas valve regulator with an integral vent limiter complies with the safety code requirements of CSD-1, CF-190(a) as shipped from the manufacturer without the installation of additional vent lines.

Two Stage Burner Control System

The 315,000 through 399,999 Btu/hr boiler models (M9) will be equipped with a two stage gas valve to control high/low burner operation. The 500,000 Btu/hr boiler model achieves two stage burner firing by staging the operation of the two combination gas valves.

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Contents Models 90,000 500,000 Btu/hr Contents Checking equipment Please read before proceedingCodes Copper-fin =B=R Rating RatingsCopper-fin Specifications Gas connection pipe Copper-fin How it worksModels CWN270 Front View Model CWN399 Front View 422 Location of unit Determine unit location3Combustion Air Direct from Outside Determine boiler location6Combustion Air from Outside Single Opening Minimum Recommended Combustion AIR Supply to Equipment Room Vent Pipe Sizes VentingConventional Negative Draft Venting System Venting Less from Ridge From Parapet Wall Vertical Vent Termination ClearancesNumber Masonry Chimney InstallationVent Materials Sidewall Venting7CB with Vent Damper and Vent Damper Terminal Block Automatic Vent DamperManifold Pressure Gas connectionsGas Supply Gas Pressure Test Gas ConnectionGas Piping Install Piping to ControlClockwise to raise regulator gas pressure, counterclockwise Gas Manifold Pressure Adjustment Procedure4Gas Supply Pressure Checking Gas Supply PressureTwo Stage Burner Control System Combination Gas ValvesVenting of Combination Gas Valves Relief Valve Water Flow Switch if equippedHydronic piping General Plumbing Rules Typical Heating Boiler InstallationsLow Water Cutoff if equipped Minimum Required Flow For Heating BoilerPiping of the Boiler System System Temperature Rise ChartCirculator Pump Requirements Heat Exchanger Pressure Drop ChartCirculator Pump Specifications Water Connections Heating Boilers OnlyPrimary/Secondary Boiler Piping Boiler Flow Rates Three Way Valves4Primary / Secondary Piping of a Single Boiler Primary / Secondary PipingNot to Exceed 4 Pipe DIA or MAX. of 12 Apart 8Multiple Boilers Zoned with Circulators Electrical connections Terminal Strip WiringBoiler Operating Temperature Control Power Venter Connection to Terminal StripOperating Temperature Control Temperature AdjustmentPump Wiring for a Heating Boiler Maximum Set Point Determination Locating Temperature ControlTemperature Control Settings Maximum SET Point DeterminationOutdoor Air Temperature Sensor Temperature Control SensorsInlet Water Temperature Sensor Multi-Purpose Temperature SensorInstallation of a Tank Sensor Water Heater Application Outdoor Air Reset OptionInstallation of a Remote Sensor Boiler Application Additional Temperature Controls Manual Reset High Water Temperature Limit Control Blocked Vent and Flame Roll-Out / Flame Interlock SwitchInitial Start-up Pre-start ChecklistStart-up 1Gas Valve 90,000 270,000 Btu/hr Models Lighting InstructionsTo Turn OFF GAS to Appliance Safety Shutoff Test For Standing Pilot Ignition SystemOperating Instructions To Turn Off Gas to Appliance Safety Shutoff Test for Spark Ignition Pilot SystemIntermittent Pilot Spark Ignition System F9/M9 Freeze ProtectionFreeze Protection for a Heating Boiler System if required Water TreatmentDomestic Water Heaters 90,000 500,000 Btu/hr Models Required Temperature RiseRequired Temperature Rise Domestic water heatersPump Operation Water ChemistrySoftened Water Systems 1Single water heatersingle tank 2Single water heatermultiple tank 3Multiple water heatersingle tank Heat Exchanger Remote Sensor InstallationThermostat Settings Minimum Pump Performance5Danger Warning Cathodic Protection Water Flow Switch if equippedPressure Only Relief Valve Thermal ExpansionSee the User’s Information Manual for instructions Maintenance and annual startupService technician Owner maintenanceMaintenance Check Relief Valve Check Expansion TankPerform Start-up and Checks Check All WiringCheck Control Settings Combustion Air AdjustmentInspection and Cleaning Procedure Inspect and Clean BurnerHeat Exchanger / Burner Access Water Circulating Pump Pilot Flame Adjustment ProcedureClear Area Inspection of Heat Exchanger WaterwaysGas Train and Controls Review with ownerTroubleshooting Pilot or replace 90,000 270,000 Btu/hr Models DiagramsSchematic Diagram F1 Unit Wiring Diagram F1 Unit315,000 399,999 Btu/hr Models Schematic Diagram F9 UnitWiring Diagram F9 Unit Diagrams Diagrams Page Revision a ECO #C06290 initial release CFA-I-S Rev a 09/10