Lochinvar 500, 90 service manual Primary/Secondary Boiler Piping

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Installation & Service Manual

4Hydronic piping

PUMP INSTALLATION AND MAINTENANCE: The boiler circulating pump must be purchased locally. For installation and maintenance information on the circulator pump, refer to the pump manufacturers instruction package included with the pump.

Primary/Secondary Boiler Piping

Heating boilers with inputs of 315,000 - 500,000 Btu/hr or

The installer must ensure that the boiler has adequate flow without excessive temperature rise. The temperature rise on a multiple zone system should be made when only the zone with the longest length and/or highest head loss is open. Low system flow can result in overheating of the boiler water which can cause short burner on cycles, system noise and in extreme cases, a knocking flash to steam. System noise may also indicate an oversized boiler.

larger installed on multiple zone systems are recommended to be installed with a primary/secondary piping system as shown in FIG. 4-4. A primary/secondary piping system uses a dedicated pump to supply flow to the boiler only. This pump is sized based on desired boiler flow rate, heat exchanger head loss and head loss in the secondary system piping only. The secondary pump, installed in the boiler piping, ensures a constant water flow rate to the boiler for proper operation. Boiler installation with a primary/secondary piping system can prevent noise problems caused by low system water flows. A primary/secondary piping system is recommended on any boiler where low water flow conditions may present an operational problem.

A primary/secondary piping system is ideal for systems filled with a propylene glycol and water mixture. A glycol and water mixture is more dense than water only and may result in a lower boiler flow rate. A lower boiler flow may cause noise on operation or short cycling of the burners. A larger secondary pump may be used on a primary/secondary system to provide an increased boiler flow rate. A glycol and water system may require from 10 to 20% more flow to compensate for the increased density of the glycol and its effect on the heat transfer process in the boiler. The exact increase in flow that may be required is based on the type and percentage of glycol added to the boiler system. Consult the manufacturer of the glycol for additional recommendations when using a glycol and water fill for your boiler system.

￿CAUTION

NOTICE

At no time should the system pressure be less than 12 PSIG.

A boiler operated with an inlet temperature of less than 140°F (60°C) must have a low temperature bypass to prevent problems with condensation. A VAL3048 - 1 1/2” LTV Valve Kit may be used. Follow the piping diagram in FIG. 4-5 to complete installation.

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Contents Models 90,000 500,000 Btu/hr Contents Please read before proceeding Checking equipmentCodes Ratings Copper-fin =B=R RatingCopper-fin Specifications Copper-fin How it works Gas connection pipeModels CWN270 Front View Model CWN399 Front View 422 Determine unit location Location of unitDetermine boiler location 3Combustion Air Direct from Outside6Combustion Air from Outside Single Opening Minimum Recommended Combustion AIR Supply to Equipment Room Conventional Negative Draft Venting System VentingVent Pipe Sizes Venting Vertical Vent Termination Clearances Less from Ridge From Parapet WallMasonry Chimney Installation Vent MaterialsSidewall Venting NumberAutomatic Vent Damper 7CB with Vent Damper and Vent Damper Terminal BlockGas connections Gas Supply Gas Pressure TestGas Connection Manifold PressureInstall Piping to Control Gas PipingGas Manifold Pressure Adjustment Procedure Clockwise to raise regulator gas pressure, counterclockwiseChecking Gas Supply Pressure 4Gas Supply PressureVenting of Combination Gas Valves Combination Gas ValvesTwo Stage Burner Control System Hydronic piping Water Flow Switch if equippedRelief Valve Typical Heating Boiler Installations Low Water Cutoff if equippedMinimum Required Flow For Heating Boiler General Plumbing RulesSystem Temperature Rise Chart Piping of the Boiler SystemHeat Exchanger Pressure Drop Chart Circulator Pump SpecificationsWater Connections Heating Boilers Only Circulator Pump RequirementsPrimary/Secondary Boiler Piping Three Way Valves Boiler Flow RatesPrimary / Secondary Piping 4Primary / Secondary Piping of a Single BoilerNot to Exceed 4 Pipe DIA or MAX. of 12 Apart 8Multiple Boilers Zoned with Circulators Terminal Strip Wiring Boiler Operating Temperature ControlPower Venter Connection to Terminal Strip Electrical connectionsPump Wiring for a Heating Boiler Temperature AdjustmentOperating Temperature Control Locating Temperature Control Temperature Control SettingsMaximum SET Point Determination Maximum Set Point DeterminationTemperature Control Sensors Inlet Water Temperature SensorMulti-Purpose Temperature Sensor Outdoor Air Temperature SensorInstallation of a Remote Sensor Boiler Application Outdoor Air Reset OptionInstallation of a Tank Sensor Water Heater Application Additional Temperature Controls Blocked Vent and Flame Roll-Out / Flame Interlock Switch Manual Reset High Water Temperature Limit ControlStart-up Pre-start ChecklistInitial Start-up Lighting Instructions 1Gas Valve 90,000 270,000 Btu/hr ModelsSafety Shutoff Test For Standing Pilot Ignition System To Turn OFF GAS to ApplianceOperating Instructions Safety Shutoff Test for Spark Ignition Pilot System Intermittent Pilot Spark Ignition System F9/M9Freeze Protection To Turn Off Gas to ApplianceWater Treatment Freeze Protection for a Heating Boiler System if requiredRequired Temperature Rise Required Temperature RiseDomestic water heaters Domestic Water Heaters 90,000 500,000 Btu/hr ModelsSoftened Water Systems Water ChemistryPump Operation 1Single water heatersingle tank 2Single water heatermultiple tank 3Multiple water heatersingle tank Remote Sensor Installation Thermostat SettingsMinimum Pump Performance Heat Exchanger5Danger Warning Water Flow Switch if equipped Pressure Only Relief ValveThermal Expansion Cathodic ProtectionMaintenance and annual startup Service technicianOwner maintenance See the User’s Information Manual for instructionsMaintenance Check Expansion Tank Check Relief ValveCheck All Wiring Check Control SettingsCombustion Air Adjustment Perform Start-up and ChecksHeat Exchanger / Burner Access Inspect and Clean BurnerInspection and Cleaning Procedure Pilot Flame Adjustment Procedure Clear AreaInspection of Heat Exchanger Waterways Water Circulating PumpReview with owner Gas Train and ControlsTroubleshooting Pilot or replace Diagrams Schematic Diagram F1 UnitWiring Diagram F1 Unit 90,000 270,000 Btu/hr ModelsWiring Diagram F9 Unit Schematic Diagram F9 Unit315,000 399,999 Btu/hr Models Diagrams Diagrams Page Revision a ECO #C06290 initial release CFA-I-S Rev a 09/10
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