Thermopile Testing - Bradford White ECO-DEFENDER EURG2DV40S N Series Service Manual

UDV Series
Closed Circuit Thermopile Testing
Closed circuit thermopile testing is the preferred method for testing the thermopile.
Step 1. Following the lighting instruction
label on the heater, proceed to light
the pilot and allow to operate for
three minutes. If the pilot will not
stay lit, hold the pilot button (rotate
the gas control knob to the pilot
position, push and hold in) during
this test.
Step 2. Using a multimeter capable of
measuring millivolts, place one lead
of the multimeter on the left side of
the wire harness and place the
second lead of the multimeter on
the right side of the wire harness.
Step 3. If meter reads 300 millivolts or higher, the thermopile is OK. If reading is
below 300 millivolts, replace the pilot assembly per service procedure II on
pages 9 & 10.
Open Circuit Thermopile Testing
Step 1. Disconnect the red and white pilot wires from the gas control.
Step 2. Using a multimeter capable of measuring millivolts, connect one lead to the
red thermopile wire and one lead to the white thermopile wire.
Step 3. Following the lighting instruction label on the heater,
proceed to light the pilot and allow the heater to
operate for three minutes. It will be necessary to
hold the gas control knob
down in the "PILOT" position
continuously throughout this
test. A reading over 400
millivolts indicates a good
thermopile output.
Step 4. A reading under 400 millivolts
indicates a bad thermopile, replace
the pilot assembly per service procedure II on pages 9 & 10.
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UDV SERVICE PROCEDURE IV
Thermopile Testing and Replacement