Bosch Singular 4000 Service Manual page 28

Service Manual
A6 Error - Main Gas Valve Check
1. Check if the main gas valve is closed.
A6 Error - Gas Valve Check
1. Check the coil for abnormalities.
(Normal: 1 – 1.5 kΩ)
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If the coil is disconnected and has short-circuited, replace the gas valve.
2. Check the applied voltage of the gas valve. (DC 105 – 135 V)
If the voltage is correct, replace the gas valve, and if the voltage is not
supplied normally, replace the control board.
Figure 19
A6 Error - Igniter Check
1. Check the gap of the igniter.
Gap: 4 – 5 mm
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2. Check the gap between the igniter and the burner.
Gap: 8 – 10 mm
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A6 Error - Ignition Transformer Check
1. First, remove phillips screw on the ignition transformer and remove
transformer for easier measurement of voltage.
Figure 20
2 8 |
KΩ
2. Check the input voltage of the igniter
Wire color: Brown-Brown (AC 105 – 135 V)
—
Figure 21
A6 Error - Flame Rod Check
1. Check if the fl ame rod is loose or separated.
2. Check for any foreign material on the fl ame rod (remove any foreign material).
Figure 22
Singular Combi Boiler - BTC 439002301 A (12.2021)
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