W DOC AIRBUS | AMM A320F

Operational Test of a Potable Water Heater

TASK 38-12-00-710-004-A
Operational Test of a Potable Water Heater

NOTE: The test of the water heater in one lavatory is given. The procedure is the same for all the other water heaters.
1. Reason for the Job
Self explanatory
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
1
CART - SERVICING, WATER, POTABLE
No specific
1
FLASHLIGHT
No specific
1
MIRROR - INSPECTION, FLEXIBLE
 B. Referenced Information
REFERENCE
DESIGNATION
TASK 12-15-38-613-001-A
Fill the Potable Water Tank System (Aircraft Electrical Power Available)
TASK 12-24-38-680-001-A
Draining of the Potable Water System (with Electrical Power)
TASK 24-41-00-861-002-A
Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01
Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02
Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A
De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01
De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02
De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 38-10-00-614-001-A
Pressurization of the Potable Water System from a Ground Air Supply
TASK 38-10-00-614-002-A
Depressurization of the Potable Water System
3. Job Set-up
Subtask 38-12-00-861-053-A
A. Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
Subtask 38-12-00-865-058-A
B. Make sure that this(these) circuit breaker(s) is(are) closed:
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
2000VULAV FWD & MID-HOT WATER-A1MBF02
** ON A/C NOT FOR ALL
2000VULAV FWD-HOT WATER-A1MBF02
** ON A/C NOT FOR ALL
2001VULAVATORY AFT-HOT WATER-D2MBB02
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-E9MBB03
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-D2MBB02
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-G9MBB03
2001VULAV AFT-HOT WATER-D/F2MBB02
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER9MBB03
2001VULAV AFT-HOT WATER2MBB02
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-E/L9MBB03
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-L9MBC04
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-D/L2MBB02
** ON A/C NOT FOR ALL
2001VULAV AFT-HOT WATER-M9MBB03
Subtask 38-12-00-010-052-A
C. Get Access
   (1) Open the lavatory door.
   (2) Open the sanitary cabinet door.
   (3) Make sure that the water heater switch is in the OFF position:
     (a) If necessary, use a FLASHLIGHT and MIRROR - INSPECTION, FLEXIBLE to find the power switch of the water heater.
   (4) Make sure that the shutoff valve in the potable water system is in the OPEN position.
Subtask 38-12-00-680-050-A
D. Drain the potable water system (Ref. AMM TASK 12-24-38-680-001).
Subtask 38-12-00-480-051-A
E. Connect the CART - SERVICING, WATER, POTABLE to the FILL port at the service panel but do not fill at this time.
4. Procedure
Subtask 38-12-00-710-055-E ** ON A/C NOT FOR ALL
A. Operational Test of the Water Heater
ACTION
RESULT
1.In the lavatory:
  • Set the water heater switch to the ON position:
    - If necessary, use a FLASHLIGHT and MIRROR - INSPECTION, FLEXIBLE to find the power switch of the water heater.
In the lavatory:
  • The water heater indicator-light does not come on.
  • The water heater does not operate.
NOTE: The indicator light on the water heater will only go off when:
  • The water heater is switched off
  • The water heater is in operation and there is an over-temperature.

2.At service panel 2023VU:
  • Fill the water system with 30 l (7.93 USgal) of water.
In the potable water system:
NOTE: You can fill the system with a minimum of 10% water quantity to do this test.

  • The potable water system is pressurized.
3.In the lavatory:
  • Operate the water faucet.
In the lavatory:
  • Water flows into the washbasin.
  • The water heater indicator-light comes on.
  • The water heater operates.
4.In the water heater system:
  • The thermo switch controls the operation of the water heater.

5.In the lavatory:
  • Turn the mixing timer control-lever to the WARM (red) position.

  • After 25 minutes, operate the water faucet.
  • Warm water flows into the washbasin.
6.In the lavatory:
  • Operate the water faucet until 1 l (0.26 USgal) of water flows into the washbasin.
In the lavatory:
  • The water heater operates.
  • After 8 minutes reheat, make sure that the mixing timer control-lever is in the WARM (red) position.
  • Operate the water faucet.
  • Warm water flows into the washbasin.
7.At the potable-water service panel:

8.In the lavatory:
  • Operate the water faucet and wait until no water comes from the water faucet.
In the lavatory:
  • The water heater does not operate.
  • The indicator light stays on.
NOTE: The Water Low Level-Sensor (in the tank of the water heater) will de-energize the heating circuit (when the water level falls below the sensor), but the indication light will stay on.
Subtask 38-12-00-710-055-F ** ON A/C NOT FOR ALL
A. Operational Test of the Water Heater
ACTION
RESULT
1.In the lavatory:
  • Put the water heater switch to the ON position:
    - If necessary, use a FLASHLIGHT and MIRROR - INSPECTION, FLEXIBLE to find the power switch of the water heater.
In the lavatory:
  • The water heater control light does not come on
  • The water heater does not operate.
NOTE: The control light on the water heater will only go off when:
  • The water heater is switched off
  • The water heater is in operation and there is an over-temperature
  • The quantity transmitter gives a low water level signal.

2.At the service panel 2023VU:
  • Fill the water system with 30 l (7.93 USgal) of water.
In the potable water system:
NOTE: You must fill the system with minimum 10% water quantity to do this test.



  • The potable water system is pressurized.
3.In the lavatory:
  • Hold your hands in the area of infra-red sensor to operate the infra-red water faucet.
In the lavatory:
  • The water heater control light comes on
  • The water heater operates
  • Warm water flows into the washbasin.
4.In the water heater system:
  • The electronic box controls the operation of the water heater.

5.In the lavatory:
  • Push the HOT (red) membrane switch on the top of the water faucet.
In the lavatory:
  • Hot water flows into the washbasin for 10 s.
6.In the lavatory:
  • Hold your hands in the area of infra-red sensor to operate the infra-red water faucet
  • Push the COLD (blue) membrane switch on the top of the water faucet.
In the lavatory:
  • Cold water flows into the washbasin for 10 s.
7.In the lavatory:
  • Hold your hands in the area of infra-red sensor to operate the infra-red water faucet
  • Push the HOT (red) membrane switch and then after 2 sec, press the COLD (blue) membrane switch on the top of the water faucet.
In the lavatory:
  • The hot water which flows from the water faucet, changes to cold within 1 s and continues to flow for 10 s.
8.At the potable-water service panel:

9.In the lavatory:
  • Operate the water faucet and wait until no water comes from the water faucet.
In the lavatory:
  • The water heater does not operate
  • The indicator light stays on.
NOTE: The Water Low level-Sensor (in the tank of the water heater) will de-energize the heating circuit (when the water level falls below the sensor), but the indication light will stay on.
Subtask 38-12-00-210-053-A
B. Examine the work area and make sure that there are no leaks.
NOTE: Leaks are not permitted.
Subtask 38-12-00-613-055-A
C. If necessary, fill the potable water system (Ref. AMM TASK 12-15-38-613-001).
5. Close-up
Subtask 38-12-00-410-053-A
A. Close Access
   (1) Make sure that the work area is clean and clear of tools and other items.
   (2) Close the sanitary cabinet door.
   (3) Close the lavatory door.
Subtask 38-12-00-862-053-A
B. De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002).
[Rev.10 from 2021] 2026.04.01 01:18:06 UTC
"Aviabrain" 2025