Coil Descaling; Coil Desooting - NorthStar 157495 Owner's Manual

7. 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 Water
Heater 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.
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.
Connect to
Pressure Washer
Inlet
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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8. Coil Desooting

Lid
Insulation Cap
Heating Coil
Heating Chamber