Lochinvar 90, 500 service manual Low Water Cutoff if equipped, Typical Heating Boiler Installations

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4Hydronic piping (continued)

A water flow switch meets most code requirements for a low-water cut off device on boilers requiring forced circulation for operation.

Low Water Cutoff (if equipped)

A hot water boiler installed above radiation level must be provided with a low water cutoff device either as part of the unit or installed at the time the boiler is installed. An electronic low water cutoff is available as a kit on all units. Low water cutoffs should be inspected every six months, including flushing of float types.

TABLE - 4A

MINIMUM REQUIRED FLOW

FOR HEATING BOILER

 

Input Btu/hr

GPM Flow

 

 

 

 

 

 

 

 

315,000

 

13

 

 

 

 

 

 

 

 

360,000

 

14.9

 

 

 

 

 

 

 

 

399,999

 

16.5

 

 

 

 

 

 

 

 

500,000

 

20.7

 

 

 

 

 

 

 

 

 

 

Minimum flow is based on a 40°F

 

 

NOTICE

 

 

 

 

temperature rise across the boiler.

 

 

 

 

 

 

 

 

Minimum flow may not prove a flow

 

 

 

 

switch installed in the boiler piping. Use

 

 

 

 

care when operating a boiler at or near

 

 

 

 

the minimum recommended flow

 

 

 

 

because conditions unique to the

 

 

 

 

installation (system pressure, operation

 

 

 

 

of multiple zone valves, glycol, variations

 

 

 

 

in flow, etc.,) may result in overheating

 

 

 

 

of the boiler water causing noise or

 

 

 

 

nuisance operation of safety limit con-

 

 

 

 

trols. Typical heating boiler applications

 

 

 

 

will operate with a 20°F to 30°F

 

 

 

 

temperature rise across the boiler.

 

Installation & Service Manual

Typical Heating Boiler Installations

General Plumbing Rules

1.Check all local codes.

2.For serviceability of the boiler, always install unions.

3.Always pipe pressure relief valves to an open drain.

4.Locate system air vents at the highest point of the system.

5.Expansion tank must be installed near the boiler and on the suction side of the pump.

6.Support all water piping.

Placing the Boiler in Operation

Filling the System: All air must be purged from the system for proper operation. An air scoop and air vent must be located close to the boiler outlet and there should be a minimum distance between the cold water feed and the system purge valve.

1.Close all drain cocks and air vents.

2.Open the makeup water valve and slowly fill the system.

3.If a makeup water pump is employed, adjust the pressure to provide a minimum of 12 psi at the highest point in the system. If a pressure regulator is also installed in the line, it should be adjusted to the same pressure.

4.Close all valves. Purge one circuit at a time as follows:

A.Open one circuit drain valve and let the water drain for at least five minutes. Ensure that there are no air bubbles visible in the water stream before closing the drain valve.

B.Repeat this procedure for each circuit.

5.Open all valves after all circuits have been purged. Make sure there are no system leaks.

NOTICE

Do not use petroleum based stop leak products. All system leaks must be repaired. The constant addition of make-up water can cause damage to the boiler heat exchanger due to scale accumulation. Scale reduces flow and heat transfer, causing overheating of the heat exchanger.

6.Run the system circulating pump for a minimum of 30 minutes with the boiler turned off.

7.Open all strainers in the system and check for debris.

8.Recheck all air vents as described in step 4, General Plumbing Rules.

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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 Conventional Negative Draft Venting System VentingVent Pipe Sizes Venting Less from Ridge From Parapet Wall Vertical Vent Termination ClearancesVent Materials Masonry Chimney InstallationSidewall Venting Number7CB with Vent Damper and Vent Damper Terminal Block Automatic Vent DamperGas Supply Gas Pressure Test Gas connectionsGas Connection Manifold PressureGas Piping Install Piping to ControlClockwise to raise regulator gas pressure, counterclockwise Gas Manifold Pressure Adjustment Procedure4Gas Supply Pressure Checking Gas Supply PressureVenting of Combination Gas Valves Combination Gas ValvesTwo Stage Burner Control System Hydronic piping Water Flow Switch if equippedRelief Valve Low Water Cutoff if equipped Typical Heating Boiler InstallationsMinimum Required Flow For Heating Boiler General Plumbing RulesPiping of the Boiler System System Temperature Rise ChartCirculator Pump Specifications Heat Exchanger Pressure Drop ChartWater Connections Heating Boilers Only Circulator Pump RequirementsPrimary/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 Boiler Operating Temperature Control Terminal Strip WiringPower Venter Connection to Terminal Strip Electrical connectionsPump Wiring for a Heating Boiler Temperature AdjustmentOperating Temperature Control Temperature Control Settings Locating Temperature ControlMaximum SET Point Determination Maximum Set Point DeterminationInlet Water Temperature Sensor Temperature Control SensorsMulti-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 Manual Reset High Water Temperature Limit Control Blocked Vent and Flame Roll-Out / Flame Interlock SwitchStart-up Pre-start ChecklistInitial Start-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 Intermittent Pilot Spark Ignition System F9/M9 Safety Shutoff Test for Spark Ignition Pilot SystemFreeze Protection To Turn Off Gas to ApplianceFreeze Protection for a Heating Boiler System if required Water TreatmentRequired 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 Thermostat Settings Remote Sensor InstallationMinimum Pump Performance Heat Exchanger5Danger Warning Pressure Only Relief Valve Water Flow Switch if equippedThermal Expansion Cathodic ProtectionService technician Maintenance and annual startupOwner maintenance See the User’s Information Manual for instructionsMaintenance Check Relief Valve Check Expansion TankCheck Control Settings Check All WiringCombustion Air Adjustment Perform Start-up and ChecksHeat Exchanger / Burner Access Inspect and Clean BurnerInspection and Cleaning Procedure Clear Area Pilot Flame Adjustment ProcedureInspection of Heat Exchanger Waterways Water Circulating PumpGas Train and Controls Review with ownerTroubleshooting Pilot or replace Schematic Diagram F1 Unit DiagramsWiring 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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