Northern Industrial Tools 157494 - Manual (Page 15)

15
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.
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.
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.
Heating Coil
Heating Chamber
Lid
Insulation Cap
Connect to
Water Heater
Outlet
Connect to
Pressure
Washer Inlet
Connect Pressure
Washer Outlet to
Water Heater Inlet