Lochinvar Shield SNA285-125 - Manual (Page 60)

60
13
Troubleshooting
Table 13B - Inlet/Outlet Tank Sensor Resistance vs. Temperature
Temperature °F Resistance Ω Temperature °F Resistance Ω
50 18,780 158 1,990
68 12,263 176 1,458
86 8,194 194 1,084
104 5,592 212 817
122 3,893 -- --
140 2,760 -- --
Table 13C - Flue Temperature Sensor Resistance vs. Temperature
Temperature °F Resistance Ω Temperature °F Resistance Ω
68 14,773 176 1,707
86 9,804 194 1,266
104 6,652 212 952
122 4,607 230 726
140 3,252 248 560
158 2,337 -- --
Checking temperature sensors
The water heater temperature sensors (inlet water, outlet water, tank water, and flue) 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.
Installation & Service Manual TM