I have a '79 H33 and my fresh water system started acting like it was sucking air, spitting out air and water out of the faucets. I replaced the pump and checked all the connections with no change. Is there a tube going down into the metal water tank under the v-berth? Could it have broken off? I hear occasional dripping in the tank when I run the pump. And yes, I made sure the tank is full! Help! Thank you!
Help! Fresh water system sucking air?
- Thread starter Stephentrapani
- Start date
Any pick-up tube necessarily has to be near the bottom so it can be a cause of the problem if loose, leaking or corroded.
Does that fitting at the top of the tank come off or do I need to cut a hole in the top of the tank?
I don't have a Hunter, but my tanks don't have pickup tubes. Water is drawn from the bottom of the tanks by the water pump. 
Tanks are manufactured with holes. Pick up tubes are added in assembly. That’s a subtle way of saying you will need access to determine if or what is happening inside. The good news is they should all come with clean out holes for obvious reasons but manufacturers leave them out unless the client specifies them so you will have to do now what they should have done then.
This is presuming the problem is in the tank - eliminate all other possibilities first to save the trouble if it’s not...
Did everything work well prior to the pump change? Other than change the pump what other hose or piping did you loosen during the process? If it worked and nothing other than the pump fittings, Go back to all fittings and ensure they are tight. Also ensure that all fitting theads are not cross threaded. I am sure it is very simple fix.
It was spitting air and not much water prior to the pump change. Changing the pump and tightening every fitting made no difference. Today I intend to cut an access hatch in the top of the tank. What else can it be but the pick up tube, right?
My 1981 31 had the same issue. I found out that the built in tank itself was not sealing. We have the glasses in tank that was stock. We tried to get it off to clean and seal, but because someone glued it down previously, I was forced to put in a new water tank.
My tank isn't airtight. It has an air hose at the top of the tank leading out to an opening in the hull. Or am I missing something?
That hose to the hull is an air vent. It is necessary UNLESS your fresh water system is/was plumbed to use city pressure water, hooked up to the boat "semi-permanently".
Some PO's did it that way when they lived aboard to reduce the wear on the
onboard pressure pump.
I really believe you've got an air leak somewhere in the system.
It could be as simple as a cracked fitting or a split hose. It doesn't take much to create
the kind of "spitting" you describe and it isn't always easy to find the source of the problem.
It just takes time and dedication.
I've got a similar problem, but I'm tied to a major interior upgrade so
I can't address the plumbing issue at the moment.
Let us know how yours is resolved.
Some PO's did it that way when they lived aboard to reduce the wear on the
onboard pressure pump.
I really believe you've got an air leak somewhere in the system.
It could be as simple as a cracked fitting or a split hose. It doesn't take much to create
the kind of "spitting" you describe and it isn't always easy to find the source of the problem.
It just takes time and dedication.
I've got a similar problem, but I'm tied to a major interior upgrade so
I can't address the plumbing issue at the moment.
Let us know how yours is resolved.
Thanks so much everyone for your help. I think I'm almost there! The pick up tube is corroded in a few spots and it seems to me smarter to just decommission it, plug it and drill a new hole for a new one. Make sense? My question: What should I make the new one out of? What would be easiest and best to use there? Rigid right? Pvc? Something better?
The corrosion on mine is within 5" of the top. There is a metal plate attached to the top five inches of the tube from the top of the tank , so it would be difficult to attach anything.
Thank you all for your help! I fashioned a new pickup tube out of CPVC and it works like a charm. I'd send a picture if the job didn't look so sloppy!