17
Maintenance
Coil Removal
Removal of the coil because of freeze breakage or to
clean soot from it, can be done quickly and easily.
1. Disconnect hose from pump/unloader to inlet side
of coil.
2. Disconnect the electrical connections to the ther
-
mostat or remove thermostat sensor.
3. Remove all the fittings from the discharge and inlet
side of the coil.
4. Remove burner assembly from combustion
chamber.
5. Remove 3 - 3/8" bolts from either side of coil and
tank assembly (these bolts are used to fasten tank
and handles to chassis).
6. Remove the two 3/8" nuts which are underneath
the bottom wrap (to keep the coil from moving).
7. Remove tank top wrap exposing insulation and
coil. Carefully bend insulation tabs at exhaust
stack.
8. Carefully fold back insulation and remove the coil.
9. Replace or repair any insulation found to be torn or
broken.
10. Reinstall new or cleaned coil by reversing steps 8
through 1.
Temperature and Pressure Relief Valve
(Pump Protector)
Machines with spray gun control offer the operator the
convenience of stopping and starting the flow of water
at the end of the discharge hose. When the spray gun
stops the flow of water, the unloader valve, back at the
machine, opens and recycles the cold water back to the
inlet side of the pump. Recycling for longer than five
minutes causes the cold water within the pump to heat
up. To avoid damage to the pump, a temperature and
pressure relief valve is installed next to the inlet side of
the pump that will open in the event the water tempera
-
ture exceeds 140° F. Therefore, while operating the
machine, do not leave the spray gun closed for an
extended period of time.
High Limit Hot Water Thermostat
For safety, PHW machines are equipped with adjust
-
able thermostats. If the temperature of the water should
exceed its operating temperature, the adjustable ther
-
mostat will turn the burner off until the water cools, then
it will automatically reset itself.
Rupture Disk
If pressure from pump or thermal expansion should
exceed safe limits, the rupture disk will burst, allowing
high pressure to be discharged through hose to ground.
When the disk ruptures, it will need to be replaced.
Optional Time Delay Shutdown Operation
Once the spray gun trigger is released, the shutdown
timer becomes activated. The machine will continue to
run in by-pass mode until the timer reaches its preset
time, 3 minutes. When that time is reached, the
machine shuts down. To restart, push the pump switch
forward.
Optional Auto Start/stop Timer Operation
Once the pump switch is turned on, simply triggering
the spray gun is all it takes to start the machine. Once
the trigger is released the timer will let the machine
bypass water for 15 seconds. It also starts an internal 5
to 60 minute lockout timer. This feature is totally adjust
-
able by the operator by adjusting the knob at the top of
the timer. We recommend setting the timer for 15
minutes. To reset the lockout feature, operator must
trigger the spray for 10 full seconds.
Landa PHW Operator’s Manual 8.917-417.0 - E
