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.
C. 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 (H2PO4).
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.
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