On-board Fresh Water Problem

[BSalinger]

My problem is very little pressure in the on-board fresh water system of my 2011 International 27FB. I filled the fresh water tank, turned on the pump, and opened only the kitchen faucet and got only a few short spurts of water and air. The pump remains running but no water.
I hooked up to city water and everything seems to work okay. It's the on-board system that is a problem.
Any advice will be appreciated.

[ventport]

You may have a plugged filter or screen in between the pump and the fresh water tank. Or you may still have a valve open used to suck RV antifreeze into the system to winterize the trailer. That would also be located between the pump and fresh water tank. Let us know what you find out. Brian

[mojo]

Pumps will lose their prime if run dry or previously winterized. You can disconnect the hose from the intake side and attach another piece of hose with a funnel and pour water into it while some one switches on the pump. Once it starts sucking water, turn off pump and reconnect input hose and try the pump. Sometimes you may have to actually blow water into the pump to get it started.

[BSalinger]

It's kinda tight where the pump is located under the closet but I'll try to check the filter and then prime the pump. I'll need to pick a piece of water line.
Thanks, for the input. I'll let you know the outcome.

[mefly2]

Another possible solutions is to get a pressure cap (~$5 at Wally) and put a very low pressure of 5-10 psi into the fresh water tank ... then switch on the pump and likely it will then pick up water ... which at that point is being "helped" into the pump.

[handn]

The previous posters are correct that an air block will cause the pump to run without generating water pressure and correct about ways to solve the air block.
I think the problem is more likely due to a suction leak because the pump produced a little pressure initially and then ran on air. The most likely place for a suction leak is on the in coming side of the water pump. Possibly it didn't get well connected when the trailer was winterized. Check the connections there. Access to my pump is easy. It is in a hinged cabinet without a pull under the street side closet. You can open the cabinet gently with a screw driver.

[BSalinger]

Well, I found the problem. A close inspection of the in-line filter found the clear housing cracked and broken at the base that was allowing air to get in. I guess my winterization didn't get all the water out and it froze….An education that will be remembered next Fall!
I picked up a replacement filter at the RV parts store, installed it, and I'm good to go.
Thanks to you folks. Really, thank you.