A.O. Smith Water Heater HWB-420

Ensure the circulator pump is turned off

Verify that the oil tube is available and in good condition

Identify the oil cups to be lubricated

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

Add 10 or 12 drops of No. 20 non-detergent motor oil to each motor oil cup

Is there any oil leakage around the oil cups?

Inspect boiler mounted gas controls for proper operation

Inspect boiler mounted electrical controls for proper operation

Is a more frequent inspection necessary based on water conditions?

Notes or observations from the inspection

Ensure the protector switch reset button is not depressed

Remove the leads from the switch from the thermocouple function block

Attach the leads from the switch to the leads from a test flashlight

Testing with Model N22T Test Kit

Turn on the flashlight. Does the lamp light up?

Are the protector switch contacts open?

Depress reset button on switch (ensure water temperature in the boiler coils is below 200°F)

Shut off electric and gas supply to the unit

Remove pressure relief valve from outlet header assembly and install drain hose assembly

Install standpipe in tee of inlet line

Inspect all safety devices including low water cutoffs for proper operation

Is more frequent inspection required based on water conditions?

Maintenance of Low Water Cutoff Device

Flush the low water cutoff device of the float type