Maintenance, Troubleshooting (cont'd), Schedule – Xylem MM 315E Models 51, 51S and 53 Boiler Water Feeders Models 51-2, 51-S-2 and 53-2 Feeder Cut-Off Combinations User Manual

Page 8

Xylem, Inc.

8200 N. Austin Avenue

Morton Grove, Illinois 60053

Phone: (847) 966-3700

Fax: (847) 965-8379

www.xyleminc.com/brands/mcdonnellmiller

McDonnell & Miller is a trademark of Xylem Inc. or one of its subsidiaries.

MAINTENANCE

SCHEDULE:

Daily
• Blow down when boiler is in operation if boiler operating

pressure is above 15 psi.

Weekly
• Blow down when boiler is in operation if boiler operating

pressure is below 15 psi.

Annually
• Disassemble and inspect/clean strainer screen.

Replace if screen is torn or not able to be cleaned.

• Remove and inspect/clean cartridge. (For Series 51

Feeders Only). Replace if poppet does not move freely
or debris cannot be removed.

• Remove head 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.

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

Use clean water to rinse components and surfaces. DO

NOT use sharp objects to scrape off any accumulations

of sediment or debris.

Unit is making noise.
(Series 51 Feeders Only)
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).

Cause: Linkages not transferring float movement to
switch.
Solution:
• Linkage pins may be worn or broken which would

require purchasing a new valve assembly:
-for 51/51-2: SA51-101-102/342500
-for 53/53-2: SA53-6/342800
-for 51-S/51-S-2: SA515-6/342100

• 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.

Water leaking from bellows
a)

Cause: Continuous exposure to chemicals with pH
higher than 9.0 will cause the solder to deteriorate.
Solution: Remove source of chemicals or consider
replacing control with one that is suitable for the
application.

TROUBLESHOOTING (cont'd)