Stack Flue Sensor (Sfs); Thermal Fuse (Tf); Float Switch (Cfs); Ignition Module Operation - Pentair ULTRATEMP ETi 220 Installation And User Manual

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Stack Flue Sensor (SFS)

The heater is equipped with a Stack Flue sensor. This sensor monitors the stack flue temperature and if needed will
shut down the heater if the stack flue temperature exceeds 185° F (85° C).

Thermal Fuse (TF)

A Thermal Fuse (TF) is a safety protection device that opens the electrical circuit if the exhaust gas temperature
reaches 215° F (102° C). The fuse cannot be reset, it must be replaced.

Float Switch (CFS)

The Float Switch (CFS) is a sensing application that shuts down the heater once the condensate level exceeds the
permitted level in the condensate container.

Ignition Module Operation

The Ignition Module, (Figure 23), is microprocessor based and operates on 24VAC supplied by the transformer. The
module utilizes a microprocessor to continuously monitor, analyze, and control the proper operation of the gas flame
holder. The module with the presence of the flame sensor, using flame rectification, allows the heater to operate.
ULTRATEMP ETI™ Hybrid Heater Installation and User's Guide
Diagnostic LED
Figure 23: Ignition Control Module
1 Flash - Air Flow Fault
2 Flashes - Flame No Call for Heat
3 Flashes - Ignition Lockout