Pressure Switch; Relief Valve; Vent Test - Pentair MiniMax 525 Operation & Installation Manual

Maintenance (contd.)

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 8.
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.
Figure 8.
If the pool is more than one floor above or
one floor below the heater, the pressure
switch may have to be replaced with a flow
switch.
Rev. K 5-31-06
Adjustment
Knob
Pressure Switch
NOTE

RELIEF VALVE

All MiniMax commercial pool heaters are equipped
with a pressure relief valve sized in accordance with
ASME Boiler and pressure Vessel Code, Section IV.
The pressure relief valve is installed in the opening
provided in the outlet header, the discharge from the
relief valve must be the same size as the valve outlet
with no reducing couplings or other restrictions in a
drain line. Install a drain line with a slope such that
it will drain by gravity. The relief valve should be
manually tested for correct operation once a year;
see Figure 9.
Pressure
Relief Valve
Figure 9.

VENT TEST

A quick check of your venting installation. Allow
heater to operate for 15 minutes. Close the doors, in
the room, then strike a wooden match and blow out
the flame. With the match smoking, hold it next to
the draft hood; see figure 10. If the smoke is pulled
up into the vent and out of the room, the venting is
correct. If it does not, you must make venting
corrections.
Figure 10.
1 1
Outlet
Inlet
Inlet Outlet Header
Draft Hood
P/N 470880