Lochinvar Condensing Boiler OFN0751

Turn the main power switch to the “OFF” position.

Shut off gas supply at the manual gas valve in the gas piping to the appliance.

Remove the 1/8" pipe plug on the flange to the factory supplied gas shutoff valve and install a suitable 1/8" fitting for the manometer tubing.

Place the tubing of the manometer over the tap once the 1/8" fitting is installed.

Slowly turn on the gas supply at the factory installed manual gas valve.

Vent any remaining air from the system using manual vents

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

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.

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?

Describe any issues found that could lead to flue gas spillage or carbon monoxide emissions