High Altitude Installations; Sequence Of Operation - Pentair ULTRATEMP ETi Installation Manual

Gas Pressure Setting Verification
15. If the combustion is satisfactory and the exhaust analysis is within the range,
complete the conversion by attaching the conversion label to the outlined
location on the lighting instructions label located in the gas panel.
16. IMPORTANT: Using a permanent fine-tip marker, mark on the conversion
label the date of conversion and the name and address of the party making
the conversion. Attach the conversion label on the area reserved for it
on the existing appliance label. Using an alcohol swab, clean the surface
before attaching the label. Peel off the backing strip and apply the label
with uniform pressure over the entire surface.
17. Reinstall the gas-side service panel.

High Altitude Installations

If your heater is installed at 2,000 feet (610 meters) above sea level or higher, derate
the heater 4% per 1,000 feet (305 M) of elevation above sea level.
For example, at 3,000 feet (914 meters) elevation, derate the heater 12%. At 5,000
feet (1524 meters) elevation, derate the heater 20%.

Sequence of Operation

An electronic temperature sensing thermistor in the manifold adapter inlet controls
the heater operation. When the inlet water temperature drops below the temperature
set on the operator control panel, the control board supplies power to the combustion
air blowers through a series of safety interlocks. The heater interlocks consist of:
• Water Pressure Switch (WPS): Senses that the pump is running.
• Automatic Gas Shut-off (AGS) Switch: Opens if the heat exchanger outlet
temperature goes above 140°F (60°C).
• High Limit Switch (HLS): Opens if the heat exchanger outlet temperature goes
above 127°F (53°C).
• Air Flow Switch (AFS): Senses the pressure drop across the air metering
orifices.
• Float Switch (CFS): Opens if the condensate overflows at the float switch due
to blockage in the condensate drain hose or neutralizer cartridge.
• Stack Flue Sensor (SFS): Monitors flue gas temperature and shuts down the
heater if the gas temperature reaches 185°F (85°C).
• Thermal Fuse (TF): Opens if the flue gas temperature reaches 215°F (102°C).
The air flow switch (AFS) senses the pressure differential between both of the air
metering orifices. As soon as there is sufficient air flow, the AFS closes, completing
the circuit to the Fan Control board. The gas ignition control then opens the gas valve
and the fuel mixture is ignited by the Direct Spark Ignition (DSI).
On a call for heat, the blower is energized for 15 seconds, the gas valve opens
simultaneously as the direct spark igniters are energized, then ignition occurs. The
heater is equipped with a digital operating control that enables the user to pre-set
the desired pool and spa water temperatures. The control enables the user to select
between pool and spa heating, and features a digital display that indicates the water
temperature.
(cont.)
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