Xylem MM 231F Series 42/42S Low Water Cut-Offs/Pump Controllers - Manual (Page 10)

D
NN
d.
To prevent serious personal injury from steam and hot water during blow-down, connect piping to
the discharge side of the blow-down valve to avoid exposure to steam discharge.
Failure to follow this caution could cause personal injury.
! CAUTION
When the water level is at its normal level
and the burner is on, slowly open the blow
down valve (NN) until it is fully open. Watch
the gauge glass (D) to see that the water
level drops. Close the valve after verifying
that the pump comes on and the burner
shuts off. If this does not occur, immediately
shut off the boiler and correct the problem
and retest.
INSTALLATION COMPLETE
1 3 /
8
"
(35 mm)
D
MM
c. Continue watching the gauge glass (D)
to see that the water continues to rise to
approximately 1a” (35mm) above the
horizontal cast line (MM). The pump
should shut off.
10