Unable to pressurize potable water tank.

Attributes
ACN	284671
Time
Date	199410
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dfw
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 24000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other ground : preflight other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	284671
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

While being pushed back at dfw, the ground crew informed me that water was leaking from the potable water service panel. I asked the ground crew to check the panel valve. Shortly thereafter I was informed the panel was normal. Everything proceeded normally until we were informed by the #1 flight attendant that she could not make any coffee, this was at approximately 24000 ft. On the climb to 33000 ft. The lavatory sinks also would not pressurize. We suspected the water service panel valve was in the wrong position and that we may be venting water overboard, I decided to divert the flight to a station where we could check the valve, and dispatch decided to return us to dfw. My main concern was that water could freeze aft of the service panel and then break loose and foreign object damage the left engine. We did not have enough fuel to fly to yyz below the freezing level, so I felt a divert was necessary. We descended below the freezing level and returned to dfw where the valve was found in the vent position. No foreign object damage was found. The aircraft was svced and we proceeded uneventfully to yyz. The next time there is any doubt about the valve position, I will have the lavatory. Sinks checked for water flow before leaving the ramp.

Original NASA ASRS Text

Title: UNABLE TO PRESSURIZE POTABLE WATER TANK.

Narrative: WHILE BEING PUSHED BACK AT DFW, THE GND CREW INFORMED ME THAT WATER WAS LEAKING FROM THE POTABLE WATER SVC PANEL. I ASKED THE GND CREW TO CHK THE PANEL VALVE. SHORTLY THEREAFTER I WAS INFORMED THE PANEL WAS NORMAL. EVERYTHING PROCEEDED NORMALLY UNTIL WE WERE INFORMED BY THE #1 FLT ATTENDANT THAT SHE COULD NOT MAKE ANY COFFEE, THIS WAS AT APPROX 24000 FT. ON THE CLB TO 33000 FT. THE LAVATORY SINKS ALSO WOULD NOT PRESSURIZE. WE SUSPECTED THE WATER SVC PANEL VALVE WAS IN THE WRONG POS AND THAT WE MAY BE VENTING WATER OVERBOARD, I DECIDED TO DIVERT THE FLT TO A STATION WHERE WE COULD CHK THE VALVE, AND DISPATCH DECIDED TO RETURN US TO DFW. MY MAIN CONCERN WAS THAT WATER COULD FREEZE AFT OF THE SVC PANEL AND THEN BREAK LOOSE AND FOREIGN OBJECT DAMAGE THE L ENG. WE DID NOT HAVE ENOUGH FUEL TO FLY TO YYZ BELOW THE FREEZING LEVEL, SO I FELT A DIVERT WAS NECESSARY. WE DSNDED BELOW THE FREEZING LEVEL AND RETURNED TO DFW WHERE THE VALVE WAS FOUND IN THE VENT POS. NO FOREIGN OBJECT DAMAGE WAS FOUND. THE ACFT WAS SVCED AND WE PROCEEDED UNEVENTFULLY TO YYZ. THE NEXT TIME THERE IS ANY DOUBT ABOUT THE VALVE POS, I WILL HAVE THE LAVATORY. SINKS CHKED FOR WATER FLOW BEFORE LEAVING THE RAMP.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.