1. Fireman’s Switch - When used with mechanical time clock, a Fireman’s switch turns
the heater OFF about 15 minutes before the pump is turned off. This is a function of the
switch, not the circuit. Recommended for single speed pumps. Circuit can also be used
as heater enable/disable signal, when needed.
2. Vent Temperature Sensor - Monitors flue vent temperature.
a. short b. open - check wiring integrity, c. over temp. d. low temp, e. extreme low (will
shut down the unit)
OPERA
TION & CONTROLS
Safety Circuit
1
2a
2b
30
2c
2d
2e
