Boiler inspection and maintenance
11
55
We reserve the right to make any changes due to technical modifications.
Installation and maintenance instructions Logano GA124 special gas-fired boiler • Issue 04/2005
11.7 Troubleshooting
Equipment required: Wiring diagram page 81 and
voltage detectors for 120 VAC and 24 VAC.
•
Check LED on aquastat.
It flashes twice: check sensor contacts S2/S1 and sensor wiring.
If OK: replace sensor.
It flashes three or four times: internal fault, replace aquastat.
LED off: Aquastat in reset code, wait 5 minutes for automatic reset.
•
24 V voltage at plugs B2/B1 on aquastat.
If not: replace aquastat.
•
Check 24 V voltage at terminals 1 and 4 of the terminal on boiler block.
If not: check wiring between aquastat (plug B2 and B1) and terminal on
boiler block.
If there is voltage at terminals 1 and 4, check 120 V voltage at terminals
L3 and N on plug X3 for the fan.
If not: check wiring between relay and terminal on boiler block and relay
and plug X1 (input voltage).
If the wiring is OK: replace relay.
If there is voltage at L3 and N on plug X3, check wiring to fan motor.
If OK: replace fan.
•
Bridge thermostat contacts R and W.
If the boiler starts, check thermostat and thermostat wiring.
Start
Close main gas valve.
Switch on power.
LED on aquastat on
continuously.
Adjust thermostat to heat
requirement (10 °F above room
temperature).
Adjust temperature control on
aquastat to heat requirement
(min. 10 °F above boiler
temperature).
Fan starts?
•
120 V input voltage at N and L at connector X1?
If not: check power supply.
•
120 V input voltage at L1/L2 and L1X/L2X on aquastat?
If not: check wiring.
If the wiring is OK: replace aquastat.
•
24 V voltage at plugs C and R on aquastat?
If not: check wiring.
If the wiring is OK: replace transformer.
No
No
