10 Part Number 550-110-592/1000
Probe type— See Figure 8
1. Clean probe type low water cutoff for proper
operation.
a. Turn off power to boiler and wait 5 minutes.
b. Drain water to bottom of gauge glass.
c. Turn on power.
d. Set thermostat to call for heat. Red neon lamp
on lower water cutoff should light.
e. Wait 5 minutes. Boiler should not fire.
f. Refill boiler to correct water line. Red lamp
should go off.
g. Wait 5 minutes. Boiler should fire.
h. Return thermostat to normal setting.
Test low water cutoff (all steam boilers)
(water boilers, if installed)
If the system is equipped with a low water cutoff, test the low water cutoff periodically during the heating season.
Figure 7 Float type low water cutoff Figure 8 Probe type low water cutoff
❏ Service periodically . . . . . . . . . . . .
2. Check float type low water cutoff for proper
operation.
a. Turn operating control to call for heat.
b. Before water gets hot, drain to bottom of gauge
glass. Boiler should shut off after water level
lowers a few inches.
c. Refill boiler to correct waterline. Boiler should
come back on.
. Boiler pressure and temperature must be low to avoid
the potential of severe burns from steam or hot water
Float type — See Figure 7
1. Clean float type low water cutoff to clear float
chamber of sediment.
a. Open blowdown valve at bottom control.
b. Drain water into a bucket.
50209
Probe type
low water cutoff
Gauge glass
assembly
Indicator lamp(s)
Test switch and
reset switch (if
manual reset)