Weil-McLain 550-141-826/1201 - Manual (Page 27)

SERVICE TECHNICIAN ONLY — read and follow completely.
Start-up
Fill the system
1. Close manual and automatic air vents and boiler
drain cock.
2. Fill to correct system pressure. Correct pressure will
vary with each installation. Normal cold water fill
pressure for residential systems is 12 psig. Boiler
water pH 7.0 to 8.5 is recommended.
Failure to maintain recommended pH
level can cause section failure and leaks.
3. Open automatic air vent one turn.
4. Open other vents.
a. Starting on the lowest floor, open air vents one
at a time until water squirts out. Close vent.
b. Repeat with remaining vents.
5. Refill to correct pressure.
When using antifreeze
Do not use automotive, ethylene glycol,
undiluted or petroleum-based antifreeze.
Severe personal injury, death or substan-
tial property damage can result.
• Use antifreeze especially made for hydronic systems.
Inhibited propylene glycol is recommended.
• 50% solution provides protection to about -30°F.
Do not exceed 50% mixture.
• Local codes may require back-flow preventer or
actual disconnect from city water supply.
• Determine quantity according to system water con-
tent. Boiler water content is listed on back cover of
manual. Percent of solution will affect sizing of heat
distribution units, circulator and expansion tank.
• Follow antifreeze manufacturer’s instructions.
• Do not add cold water to hot boiler. Thermal shock
can cause sections to crack.
To place in operation
1. Verify boiler is filled with water.
2. Open burner mounting door and verify rear tar-
get wall, floor and burner door insulations are in
proper position.
3. Verify burner mounting door is closed tightly and
burner wiring harness is connected to junction box.
4. Factory burner adjustment and settings may not be
suitable for specific job conditions. See Appendix,
page 32.
Make final burner adjustments using
combustion test equipment to assure
proper operation. Do not fire boiler
without water. Sections will overheat,
damaging boiler and resulting in sub-
stantial property damage.
5. Vent air from system. Repeat steps 4 and 5 under
“Fill the system.” Air in system can interfere with
water circulation and cause improper heat distri-
bution.
6. Check boiler and system piping for leaks. See “Tips
for water systems” on page 4.
7. Inspect breeching and venting for proper operation.
Part number 550-141-826/1211 27
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OIL-FIRED NATURAL DRAFT WATER BOILER — SERIES 3 —
Boiler Manual