13
Rev. D 1-19-00
P/N 471243
PRESSURE SWITCH
The pressure switch will keep the circuit open when the
pump is not on and operating. When the filter pump
turns on, the pressure switch closes the circuit and the
heater will operate. When the heater is installed below
water level of a spa or pool, adjustment of the pressure
switch may be required. For adjustment of pressure
switch, we recommend the following procedures.
1. Backwash the filter and clean the pump hair and
lint basket before making any adjustment to the
pressure switch.
2. Switch the circulation pump on and make sure it
is primed.
3. Push the heater power switch on and set the
thermostats to their highest temperature settings.
4. Clean the locktight off of the pressure switch
adjustment knob threads.
5. Turn the adjustment knob clockwise or away
from the micro-switch, until the heater shuts
down; see Figure 11.
6. Turn the adjustment knob counter-clockwise 1/2
turn and the heater should refire.
7. Turn the pump off
and the heater should
shut down. If the
heater does not shut
down, repeat the
procedure.
8. Switch the pump off
and on several times
to assure proper
adjustment.
PLUMBING CONNECTIONS
The Laguna 100K heater has the unique capability of
direct schedule 40 or 80 CPVC/ABS/PVC plumbing
connections. Either a Quick-Flange or Quick-Flange II
(depending on model ordered) has been included with the
Laguna 100K to insure conformity with PacFab’s
recommended CPVC/ABS plumbing procedure; see
Figure 9. Other plumbing connections can be used. The
instructions on the following pages show the methods for
successfully connecting plumbing to the inlet/outlet header
with either the Quick-Flange or Quick-Flange II.
MANUAL BY-PASS
Where the flow rate exceeds the maximum 80 GPM, a
manual by-pass should be installed and adjusted. After
adjustments are made, the valve handle should be
removed to avoid tampering.
Model
Min.
Max.*
100
20
80
* Do not exceed the maximum recommended
flow rate for the connecting piping.
VALVES
When any equipment is located below the surface of
the pool or spa, valves should be placed in the
circulation piping system to isolate the equipment from
the pool or spa.
Check valves are recommended to prevent back
siphon; see Figure 10.
Caution: Exercise care when installing chemical
feeders so as to not allow back siphoning of
chemical into the heater, filters or pump.
Installation (contd.)
Figure 11.
Adjustment
Knob
Figure 9.
MiniMax 100
High Performance Heater
COLD
POOL TEMP
HOT
OFF
ON
PacFab
GATE VALVE
PUMP
GATE VALVE
FILTER
HEATER
FROM POOL
VALVE
CHECK
TO POOL
Figure 10.
