Bradford-White Corp MI403S*F(BN Water Heater User Manual


 
THERMOC
OUPLE TESTING
See SERVICE PROCEDURE II
MAGNET ASSEMBLY TES
TING
Step 1. Disconnect thermocouple from combination thermostat/gas valve.
Step 2. Connect a thermocouple adapter (BWC P/N 239-44642-00, Robertshaw
P/N 75036) at the thermocouple location in the combination
thermostat/gas valve.
Step 3. Reconnect thermocouple to adapter. Make certain all connections are tight
(finger tight plus 1/4 turn).
Step 4. Using a multimeter capable of measuring millivolts, connect one alligator clip
to the set screw of the adapter and the other alligator clip to copper portion
of the thermocouple.
Step 5. Following the lighting instruction label on the heater, proceed to light the
pilot and allow to operate for three minutes.
Step 6. With a meter reading of 13 millivolts or greater, rotate knob of combination
thermostat/gas valve to the “OFF” position.
Step 7. The magnet should remain closed for a drop of at least 5 millivolts. You will here a “snap” or “click”
sound when the magnet opens, if you hear this sound prior to a drop of 5 millivolts, the magnet is
out of specification and the combination thermostat/gas valve should be replaced.
ECO (Energy Cut Off) TESTING
Step 1. Disconnect thermocouple from combination thermostat/gas valve.
Step 2. Using a multimeter capable of measuring Ohms (or continuity), attach one
lead (alligator clip) to the pilot tube. Insert the other lead (probe) fully into
the magnet opening, Be sure the probe makes contact only at the top center
of the magnet opening. Do not allow the probe to make contact with the
threaded sides of the opening.
Step 3. If continuity is indicated, the ECO is OK. If continuity is not indicated, the ECO has opened and the
combination thermostat/gas valve must be replaced.
SERVICE PROCEDURE RG-V
Combination Thermostat/Gas Valve
Testing and Replacement
13