Maintenance - Xylem McDonnell & Miller 47 Series Instruction Manual

TROUBLESHOOTING (cont'd)
Unit is making noise.
a) Cause: Under certain system conditions, there may be
a vibration when the valve mechanism (cartridge poppet)
is slightly open.
Solution: Install a pressure reducing valve, such as the
Bell & Gossett B-38, in the inlet water line before the
feeder valve.
Burner switch not working.
a) Cause: Cam worn or broken.
Solution: Replace cam assembly (CO-106/302900).
b) Cause: Linkages not transferring float movement
to switch.
Solution:
• Linkage pins may be worn or broken which would
require purchasing a new valve assembly
(SA47-101-102/341600).
• Float may be damaged, sediment may have
accumulated in chamber or equalizing piping may be
plugged. Perform testing to determine what the
problem may be and correct.

MAINTENANCE

SCHEDULE:
Weekly
• Blow down when boiler is in operation.
Annually
• Disassemble and inspect/clean strainer screen.
Replace if screen is torn or not able to be cleaned.
• Remove and inspect/clean cartridge. Replace if
poppet does not move freely or debris cannot be
removed.
• Remove lower float chamber and inspect internal
parts. Clean out all mud, silt, sediment and debris from
chamber, float mechanism and other waterside
components.
• Inspect equalizing piping. Clean or replace as
required.
• Check all wires for brittle or worn insulation.
• Check for leaks at gasket surfaces and solder joints.
Water leaking from bellows
a) Cause: Continuous exposure to chemicals or water with
pH higher than 9.0 can cause the solder to deteriorate.
Solution: Remove source of chemicals or consider
replacing control with one that is suitable for the
application.
Use clean water to rinse components and surfaces. DO
NOT use sharp objects to scrape off any accumulations
of sediment or debris.
Replace entire unit including equalizing piping every
10 years.
More frequent cleaning or replacement may be
required if used in locations where water treatment is
required or in applications with high make-up water
requirements.
NOTE
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