Bradford-White Corp MI30T*F service manual Defender, Temperature Sensor Testing

TheBradfordWhite

DEFENDER

Safety System®

TEMPERATURE SENSOR TESTING

If Control has gone into lockout due to excessive tank temperature (four flash, three second pause) reset control by rotating gas control knob to “OFF” position and wait a minimum of (5) minutes. Then follow lighting instructions and return gas control

knob to desired setpoint.

SERVICE PROCEDURE RG-VI

Gas Control

Testing, Disassembly & Replacement (Honeywell)

CAUTION

DO NOT use standard multimeter probes for this test. Doing so will damage connector. Use special pin type electronic probes or small diameter wire pins inserted into connector.

Observe Green LED indicator.		N
Does error code 4 (four flash, three
	second pause) continue?
	Y
Temperature Sensor Testing
	Following “Gas Control
	Disassembly/Reassembly”
instructions, disassemble Gas
Control to access temperature
	sensor.
With the temperature sensor still
in the back plate, use a multi-
meter set to the Ohms setting,
	determine the resistance of
	temperature sensor
(see caution and photos above)

Using a multi-meter set to the ohms setting, insert one meter probe (see caution) into center wire position of thermal well connector, insert the second probe (see caution) into either of the outside wire positions (see photo on left).

Alternate the probe on the outside position to the opposite outside wire position (see photo on right).

Resume normal operation.

Once the temperature sensor resistance values are known, the
water temperature must also be known to determine if the		N
resistance values are correct. See next page to obtain water			Replace temperature
temperature.			sensor
Are temperature sensor resistance values correct?
	Y
Replace Gas Control

22

22