Crown Boiler 24-03 Manuale Utente

b. Using wire or ﬁbre bristle brush clean crown of

boiler and inside of water legs.

c. Inspect target wall (903A only) for damage or

deterioration. If target wall is damaged, replace.

5. REASSEMBLE BOILER

CAUTION

Do not start the burner unless canopy,

smokepipe, burner mounting plate and all

flue plates are secured in place.

a. If removed, install the canopy taking care to

align the cerafelt strips. If strips are damaged

replace as needed.

b. Reinstall burner mounting plate to front section

making sure 3/16” diameter rope gasket is in

place and forms gas tight seal. If gasket is

damaged, replace.

c. Bolt burner to burner mounting plate. Inspect

gasket to assure adequate seal. Replace if

damaged. Connect oil line(s) and/or gas line(s).

d. Reinstall ﬂue plates making sure gasket on each

plate is in place and forms gas tight seal. If

damaged, all edges of the cleanout plates should

be sealed with Silastic sealant when reinstalled

until insulation can be replaced.

e.   If removed, reinstall jacket top.
f.  Reinstall left side panels.
g.  Reinstall smokepipe.

MAINTENANCE OF LOW WATER CUTOFF

DEVICES.

NOTICE

Probe and float type low water cutoff

devices require annual inspection and

maintenance.

1. PROBE TYPE LOW WATER CUTOFF

Although these devices are solid state in their

operation, the probe is exposed to possible

contamination in the boiler water and subject to

fouling.

It is important to physically remove the probe from

the boiler tapping annually and inspect that probe

for accumulation of scale or sediment.

Follow these steps to inspect, clean and/or replace

the probe:
a. Turn off electric service to the boiler.
b. Drain boiler water to a level below the tapping

for the probe.

c. Disconnect wiring connections between the low

water cutoff control and the probe.

d. Dismount the low water cutoff control from the

probe.

DANGER

Assure that the boiler is at zero pressure

before removing the LWCO probe. Do not

rely on the pressure gauge to indicate that

the boiler is at zero pressure. Open the

safety valve to relieve all internal pressure

prior to proceeding. Safety valve discharge

piping must be piped such that the potential

for burns is eliminated.

e. Unscrew the probe from the boiler tapping.
f. Inspect that portion of the probe that is exposed

to the boiler water for a scale or sediment

buildup.

g. Light deposits may be removed by wiping the

probe with a damp cloth. Wiping the probe

with a cloth soaked in vinegar will remove more

tenacious lime deposits. The most stubborn

deposits may be removed from the probe by

using a diluted amount (three 3 parts of water to

one (1) part) of phosphoric acid (H

WARNING

Exercise caution when handling phosphoric

acid and follow the instructions on

container label. Always use protective

clothing and equipment when working

with/near chemicals.

h. Wire brushing of the probe is not recommended

as the soft platinum guard ring sandwiched

between the ceramic insulators may be damaged.

Care must be taken not to damage this ring in

any way or the useful life of the probe may be

shortened.

i. Clean the pipe threads of the probe to remove

old, hardened pipe dope and other foreign matter.

j. Apply a moderate amount of good quality pipe

dope to the pipe threads on the probe. Leaving

the two end threads bare. Do not use PTFE

(Teﬂon) tape.

k.  Screw the probe into the boiler tapping.
l.  Mount the low water cutoff control on the probe.
m. Reconnect the control to probe wiring.
n.  Fill the boiler to its normal waterline.
o.  Add boiler water treatment compound as needed.
p.  Restore electric service to the boiler.
q.  Fire burner to bring the water in the boiler to a

boil to drive off free oxygen.

r. BEFORE RETURNING BOILER TO

SERVICE Follow the low water cutoff checkout

procedure on Pages 46 and 47.