Air lock in the water system

[sailaboutvic]

I have a airlock in our water system
The system
three water tank two at the same level under bunks and a small one in the bilge , one filler cap , the system work on an balance system has the main tanks fills it passes water to the other tanks .
We managed to run the tanks dry , stupid ,
I can get water out of the pump so it's getting that far , which makes me think that the air lock is in between the pump and hot and cold the taps , I try opening all the taps , also try opening one tap at a time but still no luck , any ideas guys .

Thanks

 

[VicS]

I have a airlock in our water system
The system
three water tank two at the same level under bunks and a small one in the bilge , one filler cap , the system work on an balance system has the main tanks fills it passes water to the other tanks .
We managed to run the tanks dry , stupid ,
I can get water out of the pump so it's getting that far , which makes me think that the air lock is in between the pump and hot and cold the taps , I try opening all the taps , also try opening one tap at a time but still no luck , any ideas guys .

Thanks

All air purged from the tank to pump connections ?

Maybe air in the pump. Try disconnecting the discharge connection from the pump to purge air from the pump.

More likely some debris from the tanks has found its way into the pump and is preventing the valves seating properly. Should not happen though if you have a strainer on the pump suction.
Try stripping and cleaning pump internals. Also check strainer

 

[duncan99210]

How long are you running the pump for? We've got a pillow tank for the forward tank and when we switch on to that tank it can often take two or three minutes running before the water gets pulled through from the tank due to air in the pipework. When the pump is running but no water coming out, can you feel air coming out of the tap? If there's no air coming out, there's a blockage somewhere in the system. If there's air coming out, then the pump is working fine, try running it for a bit longer.
Have you checked that the water tanks are in fact full? Given that you seem to have three tanks with one filler, you may have a problem with the links between tanks and not actually have full tanks. Also check the breather pipe(s) as you may have a blockage on them which is either preventing tanks filling or letting the water out of the outlet. A mate of mine had resorted to removing the inspection cap on his water tank to fill it because it would not fill via the filler until I cleaned his breather pipe for him: it would allow use of the water system because it was only partially blocked but it was a pain for tank filling.

 

[Pasarell]

On my old boat I regularly ran the tank dry without any problem. In fact when back at base it was my normal way of knowing when the tank needed refilling. A simpler system than yours with 1 tank and just H&C taps in galley and heads but the principle was the same. If water is coming from the pump I would expect it to easily push any airlock in the system out. My bet would be on a blockage somewhere after the pump or, possibly, an airlock before the pump if there is a low point in the pipe. If this was the case I would expect you to hear the pump speed change as it started pulling air rather than water.

 

[sailaboutvic]

Sorted guys , air leak between the tank and the pump .
Thanks for the help