A.O. Smith TWI 35-200, Installation, User And Service Manual

Page: 51 / 92

7. Use the pressure gauge to read the supply pressure and compare it with the value
from the appendix Gas details (see 13.3).
Note
Consult the mains gas supply company if the supply pressure is not correct. Take the
water heater out of service until the supply pressure is correct, refer to section
Decommissioning (see 8.10).
8. Set the control switch on the front of the water heater to 0 to turn off the water
heater.
9. Shut off the gas supply.
10. Disconnect the pressure gauge.
11. Tighten the sealing screw in the test nipple.
Fig. Gas supply pressure
3 4
1
2
1. Adjuster screw
2. Sealing screw
3. Gas control valve
4. Gas supply pipe
8.9.4 CO
2
value
Check the CO
2
value:
1. Open the gas supply.
2. Remove the cap (1) from the test nipple (2) of the flue gas outlet pipe.
3. Place the measurement probe of the CO
2
meter in the test nipple of the flue gas
outlet pipe.
4. Turn on the water heater (see 4.1).
5. If necessary, create a heat demand:
-
Use a hot water draw-off point to tap water, or
- Raise the setpoint of the water temperature, refer to Set the water
temperature.
6. Wait until the measured value on the CO
2
meter remains stable for some time. This
can take several minutes.
7. Compare the full load measured value to the value from the appendix Gas details
(see 13.3).
The CO
2
value at full load must be within ±1.0 vol% of the CO
2
value stated in the
table.
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0313279_TWISTER II_UKUK_
V1.1, 18-02-2019
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