38
High Limit—Auto Reset (Optional)
This heater may be equipped with an optional adjust-
able auto reset high limit temperature device.
For H and WH systems, the optional adjustable auto
reset high limit is located inside the heater near the
front of the unit. Adjust the setting to approx. 20°F
(10°C) above desired outlet temperature.
For Pool installations, the auto limit must be located to
sense the water temperature in the main line (see Fig.
17). Adjust the setting no higher than 110°F.
Variable Speed Injector Pump
Some XTherm models are equipped with dual variable
speed injector pumps, like the one shown below.
Fig. 44 shows the DIP switch settings, setpoint and
factory wiring .
Condensate Float Switch
This heater is equipped with a condensate float switch
to prevent operation when the condensate water level
is too high. The heater shutting down from the conden-
sate float switch is indicative of a blocked drain or
problem with the condensate management system.
The condensate float switch is located inside the vent
outlet plenum at the left rear of the heater.
Flow Switch
This standard, dual-purpose control, mounted and
wired in series with the main gas valve, shuts off
heater in case of pump failure or low water flow.
Fig. 43: Variable Speed Injector Pump
Fig. 44: Injector Pump DIP Switches, Setpoint
and Wiring
3
On
Off
4
5
1
2
1 - OFF
2 - ON
3 - ON
4 - OFF
5 - OFF
SETPOINT (B)
75ºF
80
85
110
90
95 100
105
115
120ºF
S3 S2 S1 Com
Ht
Req
Ht
Req
Injector Sensor
Boiler Inlet
CFH
INJECTOR PUMP WIRING
Fig. 51: Condensate Float Switch
Fig. 38: High Limit (Manual Reset)
