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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.
Assurez-vous que la chaudière est à pression nulle
avant de retirer la sonde LWCO. Ne vous fiez pas au
manomètre pour indiquer que la chaudière est à pression
nulle. Ouvrez la soupape de sécurité pour relâcher toute
pression interne avant de continuer. La tuyauterie de
décharge de la soupape de sécurité doit être raccordée
de manière à éliminer tout risque de brûlure.
c. Disconnect wiring connections between the low
water cutoff control and the probe.
d. Dismount the low water cutoff control from the
probe.
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 (H2PO4).
Exercise caution when handling phosphoric acid and
follow the instructions on container label. Always use
protective clothing and equipment when working with/
near chemicals.
Soyez prudent lors de la manipulation de l'acide
phosphorique et suivez les instructions sur l'étiquette
du contenant. Utilisez toujours des vêtements et des
équipements de protection lorsque vous travaillez avec
/ à proximité de produits chimiques.
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.
54
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 in Section IV, Paragraph E, Step 3.
2. FLOAT TYPE LOW WATER CUTOFF
During the heating season, if an external low water
cutoff is on the boiler, the blow off valve should
be opened once a month (use greater frequency
where conditions warrant), to flush out the sediment
chamber so the device will be free to function
properly.
Low water cutoffs and water feeders should be
dismantled annually by qualified personnel, to the
extent necessary to insure freedom from obstructions
and proper functioning of the working parts. Inspect
connecting lines to boiler for accumulation of
mud, scale, etc., and clean as required. Examine
all visible wiring for brittle or worn insulation and
make sure electrical contacts are clean and that they
function properly. Give special attention to solder
joints on bellows and float when this type of control
is used. Check float for evidence of collapse and
check mercury bulb (where applicable) for mercury
separation or discoloration. DO NOT ATTEMPT
TO REPAIR MECHANISMS IN THE FIELD.
Complete replacement mechanisms, including
necessary gaskets and installation instructions, are
available from the manufacturer.
D.
CHECK BURNER AND CONTROLS at least once a
year. See Section IV - Operating Instructions, Paragraph
E for control checks. See Burner Manual for burner
tests and adjustments.
E.
LUBRICATE BOILER COMPONENTS according
to manufacturer's instructions. Generally, this involves
the oil burner and circulator. This includes the type of
lubricant to use, frequency of lubrication, and points to
lubricate.
F.
INSPECT VENT PIPING and combustion air
openings monthly to ensure they are unobstructed and
free from leakage and deterioration. Also verify vent
terminal is unobstructed.
G.
INSPECT CONDENSATE DRAIN SYSTEM
monthly to verify it is water-tight and unobstructed.
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