A.O. Smith Water Heater HW-670 Propane

Ensure the circulator pump is turned off

Verify that the oil tube is available and in good condition

Identify and locate the oil cups

Add 2 or 3 teaspoons of No. 20 non-detergent motor oil to the bearing oil cups

Add 10 or 12 drops of No. 20 non-detergent motor oil to the motor oil cups

Is there any oil leakage around the oil cups?

Pilot Burner - Electronic Ignition

Open fused disconnect switch or shut off electrical power to the boiler.

Turn the gas valve control knob counterclockwise to the 'PILOT' position.

Close fused disconnect switch to restore electrical power to the boiler.

Did the pilot ignite with the combination gas valve knob set at 'PILOT' and the system calling for heat?

Adjust pilot flame to cover 3/8" to 1/2" (10-12mm) of the sensing probe tip.

Did the main burner fail to light after pilot ignition?

Check the following if the main burner fails to light

Is electrical power and gas present at the valve but it does not open when system calls for heat?

Ensure a drain line is attached to the valve to direct discharge to an open drain.

Lift the lever at the end of the valve several times to ensure it seats properly and operates freely.

Does the relief valve discharge periodically or continuously?

If the valve discharges, describe the potential cause (e.g., thermal expansion or faulty valve).

Ensure the boiler is turned off and cooled down before starting the cleaning process.

Verify that all necessary cleaning equipment and solutions are available.

Drain the existing water from the system completely.

Inspect the drained water for contaminants and note any unusual findings.

Calculate the approximate water volume of the system to determine the correct percentage of cleaning solution needed.

Add the appropriate amount of cleaning solution to the system.

Attach the leads from a millivolt meter to the thermocouple and junction block and record the reading

Is the thermocouple reading above 14 to 18 millivolts?

Transfer the lead on the junction block to other terminal and record the reading

Is the voltage supply reading between 8 to 14 millivolts?

Check the junction block connections and the protector switch leads if the reading is less than 8 millivolts

Measure the millivolt drop across the contacts