Air in water lines

[Countryboy59]

2018 International Serenity, owned since October.

Winterized with compressed air and non-alcohol antifreeze, using bypass kit in water line. Now I’m can’t get rid of air in the water lines. System works OK connected to city water. Also works OK when I put the valve in bypass and draw water from a bucket to the bypass hose. There’s a leak somewhere but I checked lines under the fridge down to the tank, no sign of any leakage. Nothing visible under the trailer. Any ideas? Anyone had this problem? Pex is easy to fix, but getting to it looks like a real pain.

[rowiebowie]

Does the air get in the lines while the pump is on, or just each time you turn it off? Have you filled the water heater (opened the bypass valves)?

While you should get all air out after a minute or so of running all lines, we often have to bleed additional air (sometimes just to get the pump running) after driving with the pump off. Only seems to happen after driving.

We too have no leaks or malfunctions we can find and pump holds pressure overnight without cycling while camping. But about 1/4th of the time, we have to bleed air after driving and don't know how it gets in there.

[Countryboy59]

Originally Posted by rowiebowie

Does the air get in the lines while the pump is on, or just each time you turn it off? Have you filled the water heater (opened the bypass valves)?

While you should get all air out after a minute or so of running all lines, we often have to bleed additional air (sometimes just to get the pump running) after driving with the pump off. Only seems to happen after driving.

We too have no leaks or malfunctions we can find and pump holds pressure overnight without cycling while camping. But about 1/4th of the time, we have to bleed air after driving and don't know how it gets in there.

Air gets in when pump is running. System holds pressure when pump shut off. Works OK when feeding through the Camco winterizing valve. I suspect an air leak somewhere, or maybe the pump itself is weak, but can’t tell for sure.

[OTRA15]

Originally Posted by Countryboy59

Air gets in when pump is running. System holds pressure when pump shut off. Works OK when feeding through the Camco winterizing valve. I suspect an air leak somewhere, or maybe the pump itself is weak, but can’t tell for sure.

Sounds like you have an air leak between the water tank and the pump IMO. Find the pump, and check all the lines leading to it, including the filter canister. Remove the filter top, and clean the strainer out, and check all hoses and hose clamps. Make sure the top of the strainer canister seats correctly and that the O-ring is OK.

First, I would fill and run the system on city water, with water heater full, and flush all the lines [both hot and cold lines] incl. outdoor shower, until every faucet/low point drain/ shower head/toilet flush run clear with no air anywhere. Air can get trapped near the low point drains sometimes.

Eliminate all other variables in other words.

Fill the water tank, with clean filtered water from a new potable water hose, and run the pump, while you can see the pump and all its hose connections. You may actually hear an air leak if the trailer and campsite/back yard are quiet.

Probably a loose hose clamp near the pump IMO.

Good luck,

Peter

[TG Twinkie]

You are sucking air at the inlet to the pump.
The inlet filter bowl may be cracked.
Loose fitting connections
Cracks in inlet hoses. Either at the tank or at the pump.
Check all the connections. Perhaps the winterizing valve is leaking. Put a plug in the end of the suction line.

[guskmg]

If you winterized through a by-pass you may not have closed it all the way when you finished. BTW, if you plumbed in your own by-pass and used a Sharkbite fitting it will suck air if installed on the suction side of the pump. Sharkbite fittting only work on a pressurized system.
guskmg

[rowiebowie]

Originally Posted by guskmg

If you winterized through a by-pass you may not have closed it all the way when you finished. BTW, if you plumbed in your own by-pass and used a Sharkbite fitting it will suck air if installed on the suction side of the pump. Sharkbite fittting only work on a pressurized system.
guskmg

Ok, I did not know that. Used one fitting on galley faucet (pressure side) so it should be ok. I also relaced a low-point drain that was leaking. Am I correct that would be suction side?

[TG Twinkie]

Low point drains are on the pressure side. Downstream from the pump.

[kenen42]

Also check the gaskets in any screw on connections (like the connection to the pump). They fall out easily when you disconnect things and disappear without you noticing. Happened to me when I de-winterized last year and gave me the exact problem you describe.