Air in Plumbing System

I take it, your pump is above the water tank like mine is. Everything between the tank and pump have to be perfectly tight. I drilled out the suction screen in the outlet of my tank and put a suction strainer right on the pump inlet and I was surprised at how tight I had to twist that strainer and bowl so it wouldn't suck any air. Another, even worse problem was a brass barb/plastic tubing connection (where it went from pex to soft tubing) just ahead of the strainer. The worm clamp was one size too big and it distorted the tube and it created a leak around the barb rather than stopping it. Craig

SaltiDawg wrote:
"The city inlet valve is under pressure, not vacuum (other post)"

Is this correct when you are not connected to city water?

Yes.......city water connection and on-board pump discharge are basically the same line

"The city inlet valve is under pressure, not vacuum (other post)"

Is this correct when you are not connected to city water?

The water pump check valve is INTERNAL.....diaphragm type

The city water check valve is inside the city water connection...plunger/spring/o-ring type (when they leak water flows out of connection when using pump....air does not get sucked back in)

Cap off that wintering valve.....
Check pump inlet strainer.........tight not sucking air
Check pump suction fitting.......not cracked sucking in air
Check connections on that winterizing hose/valve.tight not sucking in air

With water in fresh water tank turn pump on.open closet faucet hot side so air can be expelled and water heater fill up...then cold side.

Thanks all. I do have winterizing system with valve that I opened and reclosed to be sure it was closed solidly but I guess it could still be a problem. I'll cap it off and try again. I'll also look into the city water check valve and see if I can locate the check valve on the water tank side of the pump.

Larry

To answer your question yes there is a check valve between your pump and the water tank. it is right at the inlet to the pump. It's purpose is to keep water from backing up into your tank while hooked up to city water. Now as far as air getting into your system it is getting into it some place on the inlet side of your pump. Make sure all fittings are tight, do you have a antifreeze syphon valve attached to your pump? is so make sure the cap in on tight, I had mine leak air into the pump and yet it did not leak water when not in use.

You let it run out of water, and pumped your lines full of air.
So just let it run till you get solid water w/o air.

The city inlet valve is under pressure, not vacuum (other post)

If its taking on air, it has to be between the tank and the pump.
Only problem I see w/ that happening, is that if there is a leak on the intake, it is going to be visible when the pump is not on. IOWs, if air can get in, water can get out.

Is there a winterization inlet tap/valve installed between the fresh water tank and the pump inlet that is still in the winterize position?

Your city water hook up check valve is not working properly
It is not sealing and allow air in the system that will cause your water system not pressure up