STA-RITE SR333LP - Manual (Page 18)

18
WATER PRESSURE SWITCH
Hazardous pressure. Do not bypass the Water
Pressure Switch or render it inoperable.
Switch Settings
The water pressure switch turns off the burner if the water
flow is interrupted. If the water flow is restricted, the water
pressure switch may prevent the burner from firing and
cause the “Service System” light to go on. If the light
remains on after the filter has been serviced, have a quali-
fied service technician check the system.
For deck-level heater installations, the Pressure Switch is
factory set at 3 psi (20.6 kPa). If the pressure switch is one
to two feet (.3-.6M) below or one to five feet (.3-1.5M)
above the pool water level, reset the switch so that it is
open when the pump is off and closed when the pump is
running. Turn the star-wheel on the switch clockwise (
)
to raise setting (heater below the pool) and counterclock-
wise (
) to lower the setting (heater above the pool –
see Figures 18 and 19). Test the switch after resetting.
NOTICE: When the heater is mounted more than five feet
(1.5M) above or two feet (.6M) below the deck level, a
Pressure Switch is no longer adequate. A Flow Switch must
be installed instead.
NOTICE: Heater operation with incorrect Pressure Switch
setting may cause operation with no water flow. Operation
of the heater without sufficient water flow may severely
damage it.
Verify proper operation of the water pressure switch at the
start of every season and every six months thereafter by the
following steps:
1. Lower the thermostat setting to turn off the heater.
2. Wait at least 15 minutes after the burner is off, and
then turn off the filter pump.
3. Turn up the thermostat as though to fire the burner.
4. Wait one minute. The “Service System” light should go
on but the burner should not fire and the blower should
not start. If the blower or burner do start, or if the
“Service System” light does not go on, there is a pres-
sure switch malfunction. Immediately press the OFF but-
ton on the operating control to turn the burner off and
call a qualified service technician to check the system.
Live steam hazard. If the Burner and the
Pump stop at the same time, wait at least 15 minutes
before starting the filter pump to avoid severe damage to
the heater.
PRESSURE RELIEF VALVE
Canadian code requires and some U.S. local codes may
require installation of a pressure relief valve. Purchase sep-
arately and install a 3/4” pressure relief valve complying
with the ANSI/ASME Boiler and Pressure Vessel Code, hav-
ing a capacity equal to the Btu/hr rating of the heater. The
relief pressure of the valve MUST NOT EXCEED 50 PSI.
A 3/4” NPT connection is provided in the manifold for
installing a pressure relief valve. The relief valve must be
installed vertically. To install the valve, use a 3/4” brass
nipple and elbow (user supplied), as illustrated in Figure
20. No valve is allowed to be placed between the manifold
adapter and the relief valve.
Pipe relief valve discharge
to a drain or other safe
disposal site.
2681 1096
Relief Valve Installed
User
supplied
pipe
fittings 2734 1296 CAN Lower Pressure
Raise Pressure
Raise pressure set
point if pressure switch is
More than 2 feet (.6M)
below water level
Lower pressure set
point if pressure switch
is more than 5 feet (1.5M)
above water level
Back of pressure switch
has a reference scale.
FIGURE 20: Relief Valve
FIGURE 19: Water Pressure Switch Adjustment
FIGURE 18: Remove cover for access to Switch