Bosch Appliances 2400E NG, 2400E LP Heat exchanger Flame ionization rod or control unit may be

Display

Cause

Solution

F7

Ionization error at standby.

1. Loose connection to the flame ionization rod.

(part# 8708107020)

Verify that the thinner yellow wire leading from the

control unit is securely connected to the set of

electrodes located at the bottom right-hand side of

the heat exchanger.

2. Flame ionization rod or control unit may be

damaged. Contact Bosch Water Heating for further

instruction.

FA

Gas leakage error, gas valve circuit not

1. Disconnect power supply cord and check wire

closing properly.

connections on gas valve and the two connectors

(part# 8707021019)

on the control board.

2. Flow water out of a hot water tap above the

minimum activation point of .8GPM. Measure

voltage at the gas valve wire connector. The

connector should measure 24VDC between the left

pair of wires and 24VDC between the right pair of

wires when the unit is operating. If voltage is not

correct, contact Bosch Water Heating for further

instruction.

3. Gas valve may be defective, contact Bosch

Water Heating for further instruction.

8E

Electronic noise on control unit.

1. Improper resetting of other error codes. Using the

(part# 8707207239)

on/off switch or unplugging the power cord to reset

error codes can interrupt signal between

microprocessors inside control unit and show 8E on

the display. Only use the reset button (

) to reset

any error codes.

2. Possible defective control unit call Bosch Water

Heating for further instructions.

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