Failure of heated Overflow Nipple

TASK 30-72-00-810-802-A
Failure of heated Overflow Nipple

1. Possible Causes

THERMOSTAT-OVERFLOW NIPPLE [14DV]
OVERFLOW NIPPLE [13DV]
wiring

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	1	SPRAY - COOLING

B. Referenced Information

REFERENCE	DESIGNATION
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
ASM 307201
AMM 30-72-52-000-001	Removal of the Heated Fill/Drain Nipple 11DV and/or Overflow Nipple 13DV
AMM 30-72-52-400-001	Installation of the Heated Fill/Drain Nipple 11DV and/or Overflow Nipple 13DV
AMM 52-30-00-860-006	Open the Bulk Cargo-Compartment Door

3. Fault Confirmation
Subtask 30-72-00-860-052-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(2) Put an ACCESS PLATFORM 2M (6 FT) in position at the potable-water service panel 171AL.
(3) Open the BULK cargo-compartment door AMM 52-30-00-860-006.
(4) Open the sidewall panel 161DW to get access to the thermostat 14DV.

Subtask 30-72-00-865-055-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
2001VU	WATER SERVICE PANEL HEATER	15DV	D01
** ON A/C NOT FOR ALL
2001VU	POT/WASTE WIP SVCE PNL	15DV	E08

Subtask 30-72-00-710-052-A ** ON A/C NOT FOR ALL

C. Do this test:

ACTION	RESULT
1.At the potable-water service panel (inboard side): apply SPRAY - COOLING on and around the thermostat 14DV for at least 10 seconds.	At the potable-water service panel (outboard side): examine that the heated fill/drain nipple 13DV becomes warm.

4. Fault Isolation
Subtask 30-72-00-810-051-A ** ON A/C NOT FOR ALL

A. If the overflow nipple 13DV stayes cold:

replace the THERMOSTAT-OVERFLOW NIPPLE [14DV] AMM 30-72-52-000-001 and AMM 30-72-52-400-001.

(1) If the fault continues:

replace the OVERFLOW NIPPLE [13DV] AMM 30-72-52-000-001 and AMM 30-72-52-400-001.

(a) If the fault continues:

check for the subsequent signals at the terminal block 7510VT7:
- 115VAC at 7510VT7/F;
- GND at 7510VT7/A.

1 If one signal is missing:

check and repair the wiring ASM 307201.

Subtask 30-72-00-710-053-A ** ON A/C NOT FOR ALL

B. Do the test as given in Para. 3.C.

5. Close-up
Subtask 30-72-00-860-053-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to the serviceable condition.

[Rev.8 from Aug 2018] 2026.04.04 04:29:47 UTC