Air Pressure Differential - State Water Heaters SCC 40-40 Installation, User And Service Manual

8.9.2
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8. Make sure that no water comes out of the expansion valve (15) or the T&P valve (3).
If water comes out:
- Examine if the water supply pressure is greater than the specified value in the
Technical details. If necessary, install a pressure reducing valve (1).
- Examine if the expansion valve in the protected cold supply set-up is installed
correctly and is not defect. If necessary, replace the expansion valve.

Air pressure differential

Check the air pressure differential across the air pressure switch:
1. Disconnect hose H of the air proving switch and connect this side of the hose to the
+ of the pressure gauge.
2. Disconnect hose L of the air pressure switch and connect this side of the hose to the
- of the pressure gauge.
3. Turn the water heater on and set the water heater in OFF mode, refer to Turn on
the water heater (see section 4.2).
Note
Make sure that the water heater is not in ON mode or in External ON mode.
4. Set parameter 201 to FAn, refer to Settings (see section 10).
5. Read the pressure value from the meter.
6. Compare the measured value to the value from the table.
Note
When the air pressure differential is not correct, refer to Displayed errors (see section
12.1.2), error F03.
7. Set parameter 201 to dIS, refer to Settings (see section 10).
8. Press [RESET].
The water heater goes into OFF mode.
9. Set the control switch on the side of the water heater to 0 to turn off the water
heater.
10. Disconnect the pressure gauge.
11. Reconnect the hoses of the air proving switch and the gas valve.
Fig. Air pressure differential
Installation, Maintenance and Service part