Safety Controls (Air Flow Switch, Water Pressure Switch, High Limit Shut-Off Switch) - Pentair ETi 250 Installation And User Manual

SAFETY CONTROLS
AIR FLOW SWITCH (AFS)
There is one Air Flow Switch (AFS) with a control set point of 0.5"WC. This set point
is not the same as other Pentair pool heaters, (see Figure 3). The AFS is designed
as a safety device to ensure the combustion air blower is operating and is monitoring
the differential (negative) pressure within the blower housing. These air pressure
switches is factory set. The switch
ignition module. The ignition module does not operate unless the air flow switch and
the safety switch is closed.
WATER PRESSURE SWITCH (PS)
WARNING
The heater has one Water Pressure switch, see Figure 4.
If the water flow is restricted, the water pressure switch
may prevent the burner from firing and cause a Service
System message on the LCD control panel. Note: If the
light remains on after the filter has been serviced, have a
qualified service technician check the system.
For deck-level heater installations, the Water Pressure
switch is factory set at 3.00 psi (20.6 kPa). Note: See
Below Pool Level Installation, on page 23. If the
pressure switch is 1 ft (0.3M) below or 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 (
setting (heater below the pool level) and counterclockwise
( ) to lower the setting (heater above the pool level),
see Figure 5. Test each switch after resetting.
NOTICE: When the heater is mounted more than
1 ft (30 m) above or 1 ft (30 cm) below the deck level,
a pressure switch is no longer adequate. A Flow
Switch must be installed instead.
CAUTION! Heater operation with an incorrect water
pressure switch setting, may cause the heater to
operate without sufficient water flow, and may cause
severe heater damage.
HIGH LIMIT SWITCH AND
AUTOMATIC GAS SHUT-OFF SWITCH
(AGS)
A High Limit Switch (HLS), is a safety device that opens
the electrical circuit and shuts off the heater based on a
water temperature set point within the HLS. The heater
contains one AGS switch and one HLS switch. The
AGS switch is located in the outlet plumbing assembly,
and the HLS switch is located on the main Inlet/Outlet
Header (see page 9).
(see page 68) is
Hazardous pressure. Do not bypass the Water Pressure Switch or render it inoperable.
) to raise
ETi 250 High Efficiency Pool and Spa Heater Installation and User's Guide
connected upstream of the
Turn star wheel clockwise to raise pressure set point if water
pressure switch is more than 1 ft (30 cm) below water level
Turn star wheel counterclockwise to lower
pressure set point if pressure switch is more
than 1 ft (30 cm) above water level
Figure 5.
Operation Instructions
Figure 3. Air Flow Switch
Water Pressure
Switch Star Wheel
Figure 3: Water Pressure Switch
Figure 4. Water Pressure Switch
Water Pressure
Switch
Star Wheel
A reference scale is on
the back of pressure switch
15