North Star MHOTPWR - Manual (Page 15)

15
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.
2. Attach the high pressure hose to the high
pressure water outlet on the machine, do not
hook up the spray gun.
3. Place the other end of the high pressure hose in
the 5 gallon bucket.
4. Attach a short length of hose to the garden hose
inlet on the pump.
5. Prime the pump by filling the hose with water,
then place the end of the hose in the bucket.
6. Run the pressure washer in cold mode for 1 to 3
hours recirculating the cleaning solution.
Warning: Do not run the burner.
7. Dispose of the cleaning solution where it is not
harmful to animals or the environment.
8. Flush with fresh water and clean the inlet
strainer when finished.
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 fittings from the inlet and outlet of
the coil.
3. Remove the lid 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.
6. Make sure all fittings are tight before using the
machine. Use thread sealant on all threads.
Clean Inlet Strainer
When Finished
Heating Coil
Heating Chamber
Lid
Short High
Pressure Hose
00792
00791
Insulation Cap