Aqua Products RP2100 - Manual (Page 27)

PRESSURE SWITCH
The pressure switch, or heater actuator, insures
that the heater operates only when the filter pump is in
operation. It is located on the inlet/outlet header. It is
factory set at 1.75 PSI for deck level installations.
When the heater is located below the level of the spa or
pool, it may be necessary to reset the pressure switch
to compensate for the no-flow static head. If it is
necessary to reset the pressure switch, utilize the
following procedure:
PRESSURE SWITCH ADJUSTMENT:
1. With pump and heater on, turn adjustment
knob (clockwise) until a click is heard from
the gas valve.
2. Turn adjustment knob (counter clockwise)
1/4 turn.
3. Turn pump off and on several times. Heater
should shut off immediately. If it does not,
repeat steps above until proper adjustments
made.
Adjustment
Knob
Fig. #2008
PRESSURE SWITCH ADJUSTMENT RANGE
HEAT EXCHANGER HEIGHT
Fig. # 8152.0s
NOTE: If heater is installed outside of the limits shown,
a flow switch mounted and wired adjacent to the heater
must be used in place of the pressure switch.
TWO SPEED PUMPS
In some cases, the flow on the low speed is
insufficient to operate the heater. This is apparent when
the pressure switch cannot be further adjusted or if the
heater makes banging noises or goes off on high limit.
In these cases, the pump must be run at high speed
when heating the water.
CAUTION: Do not operate the heater without the func-
tion of a properly adjusted pressure switch or flow
switch.
5' Max
5' Max
FLAME ROLL-OUT SAFETY SWITCH
The heater is equipped with a thermal cutoff device
to prevent flame roll-out in the event the heat exchanger
becomes blocked. This is a "Single-use" type fusible
link or thermal fuse, that must be replaced when dis-
abled by an over temperature condition, caused by
excessive restriction in the heat exchanger flue pas-
sage.
Fig. #9177
HIGH LIMITS
The heater is equipped with two automatic high
limits. Both are located in the inlet/outlet header. Both
are set to open at 135°F.
NOTE: An erratic high limit is often characteristic of
internal heat exchanger problem, i.e. scale buildup,
defective bypass. Refer to troubleshooting sections.
Fig. # 2009
HIGH LIMIT REMOVAL
1. Shut off main electrical power switch to heater.
2. Remove inlet/outlet inspection panel.
3. Remove defective high limit and replace with a new
high limit.
4. Replace inspection panel.
PILOT SAFETY (Millivolt)
The heaters equipped with the standing pilot (milli-
volt system), have pilot generators which act as a safety
device to shut off the flow of gas to the main burners and
the pilot burner in case the pilot flame is extinguished.
The pilot burner must be manually relighted to place the
heater in operation again. Refer to the lighting instruc-
tions provided on the heater label.
PILOT SAFETY (Electronic)
The heater employs a pilot safety which closes the
main gas valve within 8/10ths of a second whenever the
pilot flame is interrupted. Pilot flame is automatically lit
when the device is powered. Unit performs its own
safety check and opens the main valve only after the
pilot is proven to be lit.
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