Install Instructions

48
Installation & Service Manual
8 Troubleshooting
Table 8-1A - Inlet Water/System Sensor Resistance vs.
Temperature
Temperature Resistance Temperature Resistance
50 19,553 158 2,004
68 12,690 176 1,464
86 8,406 194 1,084
104 5,715 212 816
122 3,958
140 2,786
Table 8-1B - Outdoor Air Sensor Resistance vs.
Temperature
Temperature Resistance Temperature Resistance
-50 490,813 20 46,218
-40 336,606 30 34,558
-30 234,196 40 26,099
-20 165,180 50 19,900
10 118,018 60 15,311
0 85,362 70 11,883
10 62,465 80 9,299
Checking Temperature Sensors
The boiler temperature sensors (inlet water, system water, and outdoor air) are all resistance type devices. The following tables
show the correct values for the sensors at various temperatures. Use an ohmmeter to read the resistance of the sensor at a known
temperature. If the resistance of the sensor does not closely match its corresponding table, replace the sensor.