Bosch 940 ES Installation And Operating Instructions Manual page 59

3. Lack of adequate combustion air. Drawing combustion air
from a room area of inadequate size will result in unstable
burner flames and noise. Improper piping of combustion air
to the outside or insufficient space will result in unstable
burner flames and noise. Ensure adequate combustion air
is provided from the unit in accordance with specifications
in chapter 4.4, page 33 Combustion Air Requirements.
4. Cross contamination. Ensure that intake and exhaust
terminations maintain required clearances as stated in
chapter 4.3, page 15. Cross contamination between intake
and exhaust may cause unstable burner flames and noise.
5. Lack of gas pressure. Inadequate gas pressure will cause
the fuel-to-air mixture (CO
will result in unstable burner flames and noise. Ensure gas
pressure is in accordance with specifications in
chapter 4.14, page 45 Measuring Gas Pressure. A gas
pressure reading is needed to proceed further. Contact
your original installer or a local certified gas technician to
obtain this reading.
6. Verify proper CO readings per chapter 7.4, page 52. CO
2
adjustments must be done by a certified gas technician
with a calibrated combustion gas analyzer.
940 ES – 6 720 644 930 (2019/09)
) to be out of adjustment. This
2
2
Troubleshooting
59