TM 10-3510-226-23
0068 00
TEST-CONTINUED
Test the Low Water Cutoff
WARNING
Allow the boiler and any associated hot water pipe, tubing or fixtures to cool at least 30
minutes before attempting any repairs. Failure to observe safety precautions may result
in serious injury or death to personnel.
CAUTION
Testing of the cutoff requires a low-water condition for the cutoff to activate. If the cut off
has failed, running the boiler with low coolant may cause irreparable damage to the
boiler.
NOTE
The low water cutoff should receive this test any time the coolant must be drained or
changed.
1. Switch the boiler off at circuit breaker No. 22 and allow the boiler to cool for at least 1 hour before
proceeding.
2. Attach a garden hose to the boiler drain valve (Figure 5, Item 14), and place the free end of the hose
in a 5-gallon container.
3. Open the drain valve (Figure 5, Item 14) and allow the boiler to drain for at least 15 minutes.
4. Switch the boiler on at circuit breaker No. 22 and have an assistant switch the boiler on at the PLC.
CAUTION
Testing of the cutoff requires a low-water condition for the cutoff to activate. If the cut off
has failed, running the boiler with low coolant may cause irreparable damage to the
boiler.
5. If the burner starts firing, shut down the boiler immediately. This indicates a failure of the low water
cutoff (Figure 5, Item 15).
6. Close the boiler drain valve (Figure 5, Item 14).
Change 1
0068 00-9
