User Guide

Jet-Set JM-2900™
6
ADJUSTING PRESSURE UNLOADER
The machine is equipped with a regulating pressure unloader to pre-
vent pressure overload in the event that the nozzle is clogged or the
output valve or spray wand trigger is off. When the machine is in the
bypass mode, the pump will continue to run. However, running in
bypass mode for extended periods will cause damage to the pump -
no more than 5 minutes. Excessive temperatures will damage the
pump and void the warranty.
The machine also comes with thermal overload protection. When
water temperature in the pump increases to 140°F (60°C), the ther-
mal relief valve will release hot water and allow cool water to enter
pump from the fresh water supply.
To adjust the unloader, loosen the lock nut and turn the knob counter-
clockwise to decrease pressure and clockwise to increase pressure.
Caution: Do not over-tighten unloader. Tighten lock nut after adjust-
ments are made.
SPECIAL APPLICATIONS
ICE BLOCKAGES
High pressure water can be used to clear an ice blockage. A 3000 psi
gas jet can clear a 4” line at an approximate rate of one foot per min-
ute. The smaller, electric jet will take twice as long. Ambient air tem-
perature will effect these times. Use a 15° nozzle with a forward jet.
DO NOT allow the incoming water supply to exceed 140°F (60°C) or
it could cause damage to the pump. Remember to follow the cold
weather precautions found in the Freeze Protection section.
FREEZE PROTECTION
To protect your machine from severe damage caused by water freez-
ing inside the components, it is important to winterize it whenever it is
subjected to freezing temperatures.
The best way to protect the system is to keep it out of the cold. Bar-
ring that, the next best way is to flush the system with anti-freeze. To
do so, simply attach a short garden hose (not to exceed four feet) to
inlet on the pump and put other end into the anti-freeze container. Be
sure to remove the nozzle from the hose. Turn the machine on to
draw anti-freeze into the system. When anti-freeze flows out of the
end of the hose, turn the machine off. Connect high pressure hose
and trigger, and follow above procedure. Cycle trigger on/off so that
the anti-freeze will flow into unloader and injector section of machine.
When preparing to operate equipment for the next job, remove the
anti-freeze. To do so, reconnect water source, turn pump on and
direct flow of anti-freeze back into container. Be careful not to dilute
anti-freeze with incoming water supply. Anti-freeze, if kept relatively
undiluted, can be used again and again.
Hoses can also be protected from freezing by using compressed air to
clear them of residual water. Remember to remove nozzle from jet
hose and hold trigger of spray wand in open position.
SHUT DOWN INSTRUCTIONS
After drain cleaning or spray washing is completed, run clear water
through the system. Always leave the output valve in the on position
when turning off motor. Turn off water supply and drain as much water
from the pump as possible. Remove water supply hose from inlet. If
you are in a cold climate, see Freeze Protection section.
VIBRA-PULSE
®
Pulsation makes the hose
vibrate, helping the jet go
longer distances and around
tight bends easier. The pulse
control valve is located on the
front of the pump. Simply turn
the valve on to engage the
pulse. Vibra-pulse is most
effective in a 1/8” hose. You’ll
notice less vibration with a
1/4” hose, and almost none with a 3/8” hose. However, the pulse is
still effective, causing the water to burst from the nozzle hundreds of
times per second. If you are still having difficulty getting hose around
a tight bend, switch to a smaller diameter hose. Turn the pulse off
before turning machine off.
10. It is often helpful to turn on the Vibra-pulse valve. The vibration
generated helps to hose overcome the friction in the line and
glide farther down the line. See Vibra-pulse section.
11. When the jet hose encounters a bend in the line, its advance
may slow or stop. The hose has a slight curve to it from the hose
reel. It may be necessary to manually feed or rotate the jet hose
to work it around the bends. If the hose won’t advance, put the
hose in a loop and rotate it a quarter to half turn so the curve of
the hose matches the pipe. It may also be necessary to pull the
hose back six inches and snap it forward to hop across a gap in
the pipe fitting.
12. Once you reach the stoppage, move the hose back and forth
through the section several times to ensure the line is thoroughly
cleared. You may also switch nozzles to a wide spray or rotary
(optional) nozzle for wall to wall cleaning action.