Page 16
LAARS Heating Systems
PURGE - SEE PAGE 18
VALVE/FLAME SEE PAGE 21
1. LIMIT CIRCUIT OPEN
SEE PAGE 17
2. NO CALL FOR HEAT/
HOT WATER
REPLACE BOILER
CONTROL
2400-224
REPLACE TRANSFORMER
AND RUN BOILER
THROUGH A FEW CYCLES
HAVE QUALIFIED
ELECTRICIAN
REPAIR FAULT IN
WIRING TO THE
BOILER
CHECK FOR VOLTAGE (24
VAC) BETWEEN YELLOW
WIRES AT BACK OF "VAC
24XFMR" CONNECTOR ON
BOILER CONTROL
GREEN LIGHT COMES ON
1. IS SERVICE SWITCH ON?
2. IS CIRCUIT ON?
3. ARE FUSES OR CIRCUIT
BREAKER OK?
CORRECT AND
RECYCLE BOILER
RUN THROUGH A
FEW CYCLES
CHECK FOR VOLTAGE
(120 VAC) BETWEEN
BLACK AND WHITE
WIRES AT BACK OF "120
VAC" CONNECTOR ON
BOILER CONTROL
DID BOILER RUN THROUGH A
COMPLETE CYCLE AS DE-
SCRIBED IN SEQUENCE OF
EVENTS PAGE 20
TEST LIMIT
CIRCUIT
PAGE 17
PUMP OPERATES
(120 V TO PUMP)
REPLACE
2400-224
CHECK
STACK
SWITCH
GENERAL TROUBLE SHOOTING
YES
NO
YES
NO
NO
YES
OK
NO
NO
0 VOLTS
120
VOLTS
0
VOLTS
24 VOLTS
*POOR SWITCH CONTACT ON RELAYS, ZONE VALVES, OR THERMOSTATS CAN CAUSE A FLASHING
GREEN LIGHT ON JOHNSON CONTROLS G856DBG - 5201.
AFTER 5 MINUTES ARE ANY
RED LIGHTS FLASHING
YES
YES
NO
REPLACE
DEFECTIVE
RESET BOILER CONTROL BY SWITCHING OFF
POWER AT SIDE OF UNIT FOR 15 SECONDS
REPLACE BOILER
CONTROL 2400-224
REFER TO FLOW
CHART FOR SPECIFIC
PROBLEM
OK
YES
CORRECT
OPEN
