21
CONDITION #3A continued …
POSSIBLE CAUSE
VERIFICATION
SOLUTION
Overfire
Reassemble boiler. Check input to
If overfired-adjust input - see
boiler using one of the prescribed
“Procedures” Section. If obtaining
methods under “Procedures” section
rate is difficult or starts are adversely
of the manual. Gas Valve regulator
affected, check that vent line tubing
cap (with O-ring gasket) and vent line
(1/8"O.D. copper) from gas valve
tubing (1/8" O.D. copper) must be
is ok. To check: remove from
securely connected at gas valve
regulator, connect to a manometer.
terminations.
Record fan pressure during purge
cycle. If no - reading, check
connections & blow line clear.
If ok and boiler is installed 3 years or
more, consider replacing gas valve
regulator.*
If “on rate” - proceed with checkout.
Condensate Traps in
Check for accumulation of
Eliminate potential for any low points
Exhaust Vent Piping
condensate in low points of exhaust
in exhaust piping or provide auxiliary
(Boiler has a one to two
vent pipe.
condensate traps. Correct any short-
second beat after starting)
cycling conditions which prevent
normal drainage.
*Circa 1994 boiler and later are equipped with gas valves which do not have replaceable regulators. These 5-yr
tune up kits do not include a replacement regulator.
CONDITION 3B - BOILER SHORT CYCLES BUT
DOES NOT RESTART
• IF GREEN LIGHT GOES OFF BOILER STOPS & RED LIGHT STAYS ON BUT
BOILER DOES NOT RESTART.
POSSIBLE CAUSE
VERIFICATION
SOLUTION
Wire Connections
Check for loose wire/connections at
Tighten or correct loose connections.
Ignition Control Module (including
ground terminals); Gas Valve;
Check that GC-4A ground wire shares
Hi-limit & Combustion Prove
common ground with transformer
Pressure Switch (PS1).
secondary.
Isolate and secure ignition cable
from contact with all other 24V and
115V wiring.
NOTE: Use only approved resistive
spark plugs w/GC-4A control.
Pressure Switch (PS1)
Turn Rocker Switch & Gas Valve top
If boiler stops short cycling, - replace
(Combustion Prove Switch)
knob to ON. Immediately after boiler
pressure switch.
starts, place jumper across PS1
Pressure Switch terminal (R-W). DO
If boiler continues to short cycle -
NOT PUT JUMPER ON UNTIL GAS
replace ignition control module
VALVE IS ENERGIZED.
following instructions packaged with
replacement. Check and verify
CAUTION: TERMINAL VOLTAGE
proper module grounding.
EXCEEDS 300 VOLTS. (Remove
jumper after test).