PROBLEM:
Steam Coil
Boiler Over
Pressurizes
(15# Safety
valve opens)
Boiler over
pressurizes
Does operating
pressure switch
open at proper
setting (check
service manual for
that steamer)?
Replace
operating
pressure
switch
No
Does the steam
solenoid stay open
with operating
pressure switch
open?
Yes
Replace steam
solenoid
Does the pressure
in the gauge
continue to rise
with no voltage to
contactor coil?
No
Replace the
weeper valve.
Does the 15#
safety valve open
with little or no
pressure on the
gauge after it has
been replaced?
No
Replace the
safety valve.
No
Scale is blocking the
plumbing to the gauge.
Delime the boiler.
PROBLEM:
Steam Coil Boiler Stops Producing Steam
Boiler stops
steaming
Does the amber
light in the reset
switch come on?
Is the temperature
sensitive dot
(surrounded by a
yellow circle) on
the water board
white?
Replace
the water board. It has
reached a temperature of
over 180
degrees.
Yes
No
No
Does boiler have
the optional
Secondary Low
Water Cut Out?
Yes
Are the probes
covered with
scale?
No
Delime boiler
Is high pressure
switch opening
prematurely?
Replace high
pressure switch
Replace the
water board
Yes
No
Yes
No
Will Boiler stop
making steam
with SLW CO
temporarily
bypassed?
Yes
Yes
Does SLW CO
open and close as
float is moved up
and down?
No
Install delay
timer for
SLWCO
Yes
Replace
Secondary Low
Water Cut Out
switch.
No
Yes
Replace
operating
pressure
switch.
Does steam coil
leak?
Yes
Yes
Replace steam
coil
Yes
No