Troubleshooting - Crown Boiler BSI Series Installation, Operating And Service Instructions

The following pages contain trouble shooting tables for use in diagnosing control problems. When using these tables the
following should be kept in mind:
1) This information is only meant to be used by a professional heating technician as an aid in diagnosing boiler problems.
2) Where applicable, follow all precautions outlined in the Section XI (Start-up and Checkout).
3) In general, these tables assume that there are no loose or miswired electrical connections. Before using these tables in-
spect all electrical connections on the boiler to make sure that they are tight. Also, check the wiring on the boiler against
the wiring diagram in Figures 10.1 and 10.2.
4) When checking voltage across at wiring connectors (such as at the vent damper harness plug) be careful not to insert the
meter probes into the metal sockets. Doing so may damage the socket, resulting in a loose connection when the harness
is reconnected.
5) The possible causes at the end of each branch in these charts are not listed in order of likelihood. All controls on the BSI
are tested at least once in the manufacturing process and a defective control or component is generally the least likely
cause. Before replacing a component, try to rule out all other possible causes.
6) These troubleshooting charts assume that the vent damper is closed at the beginning of the troubleshooting process. With
120 volts applied to the boiler and no call for heat, the damper should go to the closed position. If it does not, do the
following:
•
Confirm that 120 volts is applied to the boiler and that there is no call for heat.
•
Make sure that the switch on the damper is in the "automatic" position.
•
Unplug the harness from the damper and check for 24 volts across pin #1 (blue) and pin #4 (yellow).
•
If voltage is present, the damper is defective or there is an obstruction in the path of the damper blade.
•
If no voltage is present, there is either a loose connection in the damper harness or the transformer is defective.
7) If the charts indicate that the transformer is defective, it is possible that this transformer has been destroyed by a short
circuit in the boiler wiring. Before replacing the transformer, carefully inspect all low voltage wiring on the boiler for
places where it is touching the frame of the boiler or wiring on the other side of the transformer.
8) If the charts indicate that the R8225 relay is defective, there is a good chance that a second transformer is present in the
thermostat circuit, resulting in the application of 48 volts across the relay coil. In older buildings, this transformer may be
hidden in a location far from the boiler. If this second transformer exists, it must be found and removed before the R8225
is replaced.
XIV Troubleshooting
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