Test 4: Upper Temperature Probe Continuity Check - A.O. Smith SERIES 120 Service Handbook

TEST 4: UPPER TEMPERATURE PROBE CONTINUITY CHECK

Conditions:
• Power On - Water below temperature set point.
• Red, water heater control "Reset Status" LED-OFF
• "Call For Heat" LED off.
TEST 4
IF.........
Test indicates no continuity
Continuity is indicated
Table 4
Servicing should only be performed by a Qualifi ed Service Agent
TROUBLESHOOTING
Upper Temperature probe continuity check
Red wire to red wire - Turn supply power "Off" for this test
then............
replace probe.
Probe should be okay.
(Also verify Ohms resistance for water temperature. Reading will be approximate.)
Figure 23
OHMS RESISTANCE TABLE
° F
70°
120°
140°
180°
30
Ohms
11,884
3,759
2,488
1,169