Northern Industrial Tools 157494 specifications VII. Coil Descaling, VIII. Coil Desooting

VII.) Coil Descaling

In hard water areas, scale build-up within the heating coil will occur. Scale deposits will decrease the water temperature rise and may eventually clog the heating coil.

1.Mix scale remover in a 5 gallon bucket and elevate the bucket so it is higher than the pump on your pressure washer.

2.Attach water heater’s inlet hose to the high pressure outlet of your pressure washer.

3.Attach high pressure hose to the outlet of the water heater, but do not hook up the spray gun.

4.Place the other end of the high pressure hose in the 5 gallon bucket.

5.Attach a short length of hose to the garden hose inlet on your pressure washer.

6.Prime the pump by filling the short length of hose with water, then place the end of the hose in the 5 gallon bucket.

Connect to	Connect to
	Pressure
Water Heater	Washer Inlet
Outlet

Connect Pressure

Washer Outlet to

Water Heater Inlet

7.Run the pressure washer in cold mode for 1 to 3 hours recirculating the cleaning solution.

Warning: Do not run the burner.

8.Dispose of the cleaning solution where it is not harmful to animals or the environment.

9.Flush with fresh water and clean the inlet strainer when finished.

VIII.) Coil Desooting

Poor grades of fuel oil or inadequate combustion air will cause heavy soot build-up on the outside surface of the heating coil. These deposits will insulate the coil. This will restrict the air flow through the coil, further aggravating the soot build- up.

Most coils will never require desooting. However, to desoot a coil...

1.Wear protective clothing, goggles, and gloves.

2.Remove the flow switch from the inlet of the heating coil and remove the thermostat from the outlet of the heating coil.

3.Remove the lid and insulation cap from the heating chamber and hoist the coil out. Be careful, the coil is very heavy.

Important: Be careful not to damage the threads on the coil inlet and outlet. If the threads get damaged, it will be hard to reconnect and seal the fittings on the coil inlet and outlet.

Lid

Insulation Cap

Heating Coil

Heating Chamber

4.Clean the coil.

5.Reassemble the coil to the machine. Make sure the white insulation remains in place. Reattach the flow switch and thermostat, using thread sealant. Make sure all fittings are tight before using the machine.

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