Lochinvar Condensing Boiler OFL1251

Disconnect the two external wires connected to the enable terminals on the connection board.

Connect a voltmeter across the two incoming wires and close each thermostat, zone valve, and relay in the external circuit one at a time. Record the voltmeter reading across the incoming wires.

If a voltage occurs, was the external wiring checked and corrected?

Reconnect the external thermostat circuit wires to the connection board.

Measure the water hardness in grains per gallon

Is the water hardness between 5 and 12 grains per gallon?

Consult local water treatment companies for hard water areas (above 12 grains per gallon hardness)

Measure the pH level of the water

Is the pH level between 6.5 and 8.5?

Total Dissolved Solids (TDS) Check

Measure the Total Dissolved Solids (TDS) in ppm

Ensure the water meets the requirements of the manual before filling the system.

Close automatic and manual air vents and boiler drain valve.

Fill to correct system pressure.

Enter the minimum cold water fill pressure for the system.

Check if the pressure rises when the boiler is turned ON and system water temperature increases.

Check the system thoroughly for any leaks during initial fill and boiler startup.

Repair all leaks before proceeding further.

Ensure the gas supply is turned off before starting the procedure.

Verify that the area is well-ventilated to prevent gas accumulation.

Ensure all ignition sources are removed from the area.

Disconnect the flanged connections to the venturi and the blower.

Remove the existing gas valve carefully.

Install the new gas valve with flanged connections to the venturi and the blower.

Check for gastight seal at every connection, seam, and vent piping

Is the venting system sealed gastight to prevent flue gas spillage and carbon monoxide emissions?

Acknowledge understanding of the safety warning regarding the importance of a gastight seal to prevent severe personal injury or death.