fresh water pump air lock?

[markawilson]

Good morning and thanks for any comments or advice!

I inadvertently ran the fresh water tank to empty (again) and lost pressure on the fresh water system; filled the tank and then tried (as I have had to do in the past with eventual success) to get the air out of the system and have the pump come back on and maintain pressure. After 2-3 hours of messing with it could not get the pump to start back up. I opened the bleed nut on the pump while engaging the pump manually for +/- 30sec to 1min, and did all the tricks that seemed to work before, like leaving the hose pipe running in the tank filler to push the air out, and opening and closing the faucets on the boat, etc. But all to no avail, could never get the pump to 'grab' and kick in.
Is there any established procedure (cause I am just guessing) or sure fire technique?
I am thinking it is possible my pump died and the tank may not have been empty (no guage on the tank) after all though I suspect it is just airlocked, cause I have had this battle before and swore to not let the tank go empty again!

Any suggestions or thoughts?

My boat is a 1990 41C convertible visiting at a distant marina for yard work.

Thanks!

 

[Pascal]

hard to say without knowing what kind of pump you have !!!

if you have a galleymaid like many hatts you need to open the plug on top of the stator and pour water in to prime it. how far is the pump from the tank ? you may need to manually refill the line...

the manual for the galleymaid says that you need a check valve close to the tank pickup, check that too.

how long did the pump run dry ? could the stator be damaged ?

 

[DCMY #92]

I have three suggestions.

You might have an air leak in the suction line from the tank pickup to the pump inlet.

If you have a strainer in the suction line it may be clogged by debris picked up when the tank went dry.

I don't know what kind of pump you have, but I once had a Shurflow develop an air leak in the metal casing that houses the valves. It had to be replaced before the pump would prime.

 

[Trojan]

If your pump is not an impeller type pump or gear type and you ran it dry. Like Pascal said, you will have to prime the pump. The check valve will hold the prime once you get water. Unless you get lucky without priming you will get no water.

BILL

 

[Will]

I used to have similar problems with my GalleyMaid pump. Since however, I've had many successes with the following procedure:
1. Fill the water tank to the very top. Leave the cap off of the water fill fitting. If your tank vent is lower than the level of the pump, try closing off the vent. The objective is to make the water level in the tank higher than the level of the bleed valve at the top of the stator housing on your pump.
2. Open the bleed valve on your water pump long enough to make certain that you get all of the air out of the line between your water tank and the pump. The high water level in your tank should force all of the air out of the line.
3. Close the bleed valve.
4. Crack open a water faucet close to the pump (to allow air in your water system to bleed out).
5. Manually start the pump. It should build up enough pressure to run automatically within 10 to 20 seconds.
6. Open up the vent to your water tank if it was necessary to close it off.
I hope this works as well for you as it has for me.
Will

 

[Captned]

Replace it with one of the new fancy Shurflow ones. I have been very happy with mine...

M2C

Captned
78 46 CON

 

[markawilson]

Thanks friends! All good comments. Sounds like Will has been in the exact same situation and has a technique to resolve it, IF i have not developed a problem in the water line somewhere, where I am getting an air leak. As I said it is possible the line/pump developed a problem and I may not have even run the tank dry. Have had very large mechanics in the engine room for a month rebuilding the starboard engine and one of them could have smushed the line. I have a place to start and thank you!

Mark Wilson
Angelus Pennae, 41C Hatteras convertible
markawilson@cox.net