Weil-McLain BCP-3 - Manual (Page 14)

14
BCP-3 Installation and Operation Manual
Troubleshooting
No Display or LED Lights
Check the power to the BCP-3. The BCP-3 requires 120VAC power to the Black wires or 24VAC to the right-most terminals.
Turn the power off and back on to restore the display. If unsuccessful, make sure that the control's Display Cover is securely
mounted to the Base.
System or Outdoor Reads OPEN or SHORT
If the sensor reads Open, short the sensor input terminals. The display should read SHORT. If it doesn’t, the BCP-3 may be
damaged.
If the sensor reads Short, remove the wires from the input terminals. The display should read OPEN. If it doesn’t, the BCP-3 may
be damaged.
System or Outdoor Sensor Reads an Incorrect Temperature
Remove the sensor wires from the input terminals. The display should change to read OPEN. If it doesn’t, the BCP-3 may be
damaged. Take an ohm reading across the detached sensor wires. The ohm reading should correspond to the Temperature Sensor
Chart. If the difference is within 5°F adjust the sensor Trim. Otherwise, the sensor may be damaged.
No Heat - All LEDs are OFF
Check the outdoor temperature and the Outdoor Cutoff readings. If the outdoor temperature is above the Outdoor Cutoff, the
BCP-3 will not give heat. If the display shows
TSTAT OPEN then, check the EXT terminals. If the EXT terminals are not
jumped together, the BCP-3 will not give heat.
No Heat - All LEDs are ON
First, make sure that the system pump is running. Remove any connections to the Yellow wires for the Heating System Pump.
Test for continuity across the pair of Yellow wires. If the wires are continuous, the BCP-3 is calling for the Heating System Pump
to run and the problem is not with the BCP-3. Check the power source to the pump and the pump to determine why it is not
circulating.
Second, check the boiler operation and safety control status.
No Heat - System Pump LED ON
Check that the displayed System water temperature is below the Target water temperature minus the Differential. If not, wait
until the System temperature falls, and then the stage LED should come on and the boiler should fire. Otherwise, remove all
connections from the Blue pair of wires. Check for continuity across the pair of Blue wires using a meter. If the wires are
continuous, the BCP-3 is calling for the boiler to run. Check the boiler to determine why it is not firing.
No Heat - Boiler LED ON
The BCP-3 is registering a call for DHW. If the DHW Priority is
set to a value other than NO, the Heating System Pump will not run
during the priority period of a DHW call. Generally, the DHW will
be satisfied before a drop in ambient temperature is noticeable. If
the DHW load is large or the boiler can satisfy both loads, change
the Priority setting to NO, this will allow the Heating System Pump
to circulate hot water to the building while the DHW tank is being
satisfied.
Temperature Sensor Chart
TEMPERATURE
(in Degrees °F)
Value
(in Ohms)
-30 117720
-20 82823
-10 59076
0 42683
10 31215
20 23089
25 19939
30 17264
35 14985
40 13040
45 11374
50 9944
55 8714
60 7653
70 5941
80 4649
90 3667
TEMPERATURE
(in Degrees °F)
Value
(in Ohms)
100 2914
110 2332
120 1879
130 1524
140 1243
150 1021
160 842
170 699
180 583
190 489
200 412
210 349
220 297
230 253
240 217
250 187