Filter
Top Products
See SERVICE PROCEDURE AG-I
THERMOCOUPLE TESTING
MAGNET ASSEMBLY TESTING (White Rodgers Control)
SERVICE PROCEDURE AG-III
Combination Thermostat/Gas Valve
Testing and Replacement
Page 7
Step 1. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for
three minutes. Ifthe pilot will not stay lit, hold the pilot button (located on the combination
thermostat/gas valve) down during this test
Step 2. Using a multimeter capable of measuring millivolts, connect one lead
using an alligator clip to the copper sheath of the thermocouple, use the second lead of the multi meter to
probe the top terminal located at the back of the combination thermostat/gas valve.
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 6 millivolts. You will here a “snap” or “click” sound
when the magnet opens, if you hear this sound prior to a drop of 6 millivolts, the magnet is out of
specification and the combination thermostat/gas valve should be replaced.
MAGNET ASSEMBLY TESTING (Robertshaw Control)
Step 1. Disconnect thermocouple from combination thermostat/gas valve.
Step 2. Connect a thermocouple adaptor
(Robertshaw P/N 75036) at the thermocouple location
in the combination thermostat/gas valve.
Step 3. Reconnect thermocouple to adaptor. Make certain all connections
are tight (finger tight plus ¼” turn).
Step 4 Using a multimeter capable of measuring millivolts, connect one
alligator clip to the set screw of the adaptor 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 minuets.
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 6 millivolts. You will here a “snap” or “click” sound
when the magnet opens, if you hear this sound prior to a drop of 6 millivolts, the magnet is out of
specification and the combination thermostat/gas valve should be replaced.
Probe top terminal on
back of combination
thermostat/gas valve
Alligator clip to copper
sheath of thermocouple
7