Weil-McLain 550-141-826/1201 - Manual (Page 7)

HOMEOWNER and SERVICE TECHNICIAN — read and follow completely.
Troubleshooting
Homeowners — The problems and corrections below represent common situations that can occur. There may be
others not listed below. It is important always to contact a qualified service technician if you have any questions
about the operation of your boiler or system.
Common Problems Common Causes Possible Corrections
Rapid cycling — burner
turns on and off frequently. Thermostat installed where
drafts or heat affect reading.
Locate thermostat on inner wall away from heat sources or cool drafts.
Heat anticipator in thermo-
stat adjusted incorrectly.
Adjust heat anticipator to match current draw. Refer to boiler wiring
diagram.
Incorrect limit setting. Have qualified service technician increase limit setting to decrease
cycling. Maximum setting 220° F.
Need to frequently add
makeup water. Leaks in boiler or piping. Have qualified service technician repair leaks at once to avoid constant
use of makeup water.
Popping or percolating
noise heard in boiler. Mineral deposits in sections
due to constant use of make-
up water, or incorrect pH.
Have qualified service technician de-lime boiler, repair leaks at once
to avoid constant use of makeup water and check pH (between 7.0
and 8.5).
Black water condition. Oxygen corrosion due to
leaks in piping.
Have qualified service technician repair leaks at once to avoid constant
use of makeup water and check pH (between 7.0 and 8.5).
Frequent release of water
through relief valve. Expansion tank sized too
small or water-logged.
Have qualified service technician check expansion tank operation.
Metal flakes found in
flueway. Contaminated combustion
air supply.
Remove sources of hydrocarbons in or near boiler area. (Bleaches,
cleaners, chemicals, sprays, fabric softeners, paint remover, etc.)
Condensation of combustion
gases.
Have qualified service technician check boiler operation.
Some radiators or
baseboard units do not
heat or are noisy. Air in system. Bleed air from system through air vents in radiators or baseboard units.
Low system pressure. Have qualified service technician check for leaks in boiler or piping
at once.
High limit set too low. Have qualified service technician adjust limit to higher setting.
Domestic water from
tankless heater is hot then
suddenly turns cold.
OR
Domestic water from
tankless heater is always
lukewarm. Mineral deposits insulate
internal waterways of heater.
Have qualified service technician delime or replace coil.
Boiler stop-leak compound
has been added to boiler wa-
ter and is insulating outside
of coil.
Have qualified service technician remove and clean coil and drain,
and flush boiler to remove stop-leak.
Incorrect mixing valve setting
for tankless heater.
Have qualified service technician adjust mixing valve setting.
Domestic flow rate too high. Have qualified service technician install flow check valve set to rating
of tankless heater.
Incorrect setting on tankless
heater control.
Have qualified service technician raise tankless control setting. Adjust
differential on tankless control to lower setting.
Part number 550-141-826/1211
7
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OIL-FIRED NATURAL DRAFT WATER BOILER — SERIES 3 —
Boiler Manual