5-11
TROUBLESHOOTING
SL 30-175, SL 45-260 MODULATING GAS BOILERS
SYMPTOM
DIAGNOSIS
REMEDY
INSUFFICIENT HEAT
Operating
temperature too low.
increase temperature target. see
Section 2.7
Priority parameters
or load configuration
improperly set up.
Review load configuration parameters. See
Section 2.7
Unit undersized.
refer to load Calculation vs. Boiler output.
Air trapped within
system.
Bleed system as required.
Improper system
piping.
refer to recommended piping in
Section 1.6
System pump
undersized.
Check pump manufacturer’s data/check temp
differential across heat exchanger.
Poor gas/air mixing.
Check Co
2
level.
Defective thermostat.
refer to manufacturer’s instructions.
Obstruction in
condensate drain.
inspect and clean condensate drain.
Unit cycling on
operating/ safety
controls.
Check operation with ohmmeter/Voltmeter.
System radiation
undersized.
Check manufacturer’s rating tables for capacity
per foot.
TEMPERATURE ExCEEDS
THERMOSTAT SETTING
Incorrect anticipator
setting.
Check with ammeter.
Thermostat not level.
Check level.
ONE OR MORE ZONES DO
NOT HEAT PROPERLY
Air trapped within
zone(s) piping
Vent system/zone as required.
Insufficient radiation/
excessive heat loss.
Check actual length of pipe using radiation / heat
loss calculation.
Insufficient flow rate
to zone(s).
Check temperature drop across zone.
Defective zone valve/
zone circulator.
Check operation per manufacturer’s instructions.
5.3.4 Temperature Problems
Summary of Contents for SL 30-175
Page 76: ...NOTES...
