So I think my freshwater vent line is plugged?-gctid808334

[tdcooper99]

Been having odd issues with my freshwater system... pump not shutting off automatically, weird fizziness at the tap... all in all, something not right. However, every time I remove the freshwater fill cap, I get a big vacuum suck of air in and everything is ok for a bit. When I close it all up again, run some taps... put my ear to the vent.... NADA. And today, filling.... every so often i get a volcano eruption from the fill pipe! Big old air bubble trapped that comes back out when it SHOULD be venting! So... how to fix it? Compressed air blast from the vent exit on the hull? Anyone experienced this?

[Mr._Darcy]

Have the same trouble on a 3270 except that the vent shoots out water when filling the tank and it just hits full. Then little if any venting when drawing from the tank. Vent fitting is clear. Can blow air through the hose. ??? Maybe the hose needs to be replaced. Another project.

Greg

[builderdude]

Cooper, it does sound like your vent is blocked. Could be at the hull fitting, could also be a kinked vent hose.

[builderdude]

Darcy, probably normal for the vent to spill water when the tank becomes full, your fill fitting is likely higher than the vent fitting.

[Ruffryder]

Yup what Dave said ...all normal

[dmcb]

put your garden hose to the vent and flush it out.

Doug

[Mr._Darcy]

Hey guys, I realize it is normal to burp water when filling the tank. My concern is that the water flows out, the fitting is clear, I can blow air through the hose, but it won't vent when pumping water. Is it possible the hose is deteriorated inside and causing a venting problem?

Greg

[MidnightSun]

"Mr. Darcy" post=808468 wrote:
Hey guys, I realize it is normal to burp water when filling the tank. My concern is that the water flows out, the fitting is clear, I can blow air through the hose, but it won't vent when pumping water. Is it possible the hose is deteriorated inside and causing a venting problem?

Greg

If you are getting any kind of burping then the vent is not working correctly. After so many years, you may want to look into replacing the vent hose as they do get quite nasty with mold and mildew. Probably got brittle and kinked. I have always put the hose directly into the filler port and opened the tap full bore, no burping or bubbling just water entering the tank. Eventually it comes out the vent but usually around the same time it overflows from the filler port.

[floatyerboat]

The vents themselves can become plugged. I know my hoses are clear because I just replaced them. I semi unplugged the vents but I am going to replace them eventually. I've been around tanks and pumps pretty much my whole career. If you have any air in the system it will continue to make the pump run. Air compresses, water will not. As someone suggested on another post open the filler cap and see if your pump primes and shuts off.

[Four_Pyrates]

"tdcooper99" post=808334 wrote:
Been having odd issues with my freshwater system... pump not shutting off automatically, weird fizziness at the tap... all in all, something not right. However, every time I remove the freshwater fill cap, I get a big vacuum suck of air in and everything is ok for a bit. When I close it all up again, run some taps... put my ear to the vent.... NADA. And today, filling.... every so often i get a volcano eruption from the fill pipe! Big old air bubble trapped that comes back out when it SHOULD be venting! So... how to fix it? Compressed air blast from the vent exit on the hull? Anyone experienced this?

If you don't already have one, you should change the vent to a stainless screened vent. Much better. Next, it sounds like you may have leaks in the system. It should be turn on the water and once off, the pump comes to pressure and stops and it should hold that pressure. Spewing and short pump runs indicates a leak in addition to blockage.

If you decide to replace the vent, you can punch out the screens on the old one and see if that relieves some pressure, but you MUST replace the screens. Why? Because if a "skeeter" gets in that tank and drops some eggs, you can get really sick from that water.

[tdcooper99]

Thanks, all good advice. I'll look at replacing the vent line and vent outlet. I do know there is some nastiness in that tank... my filter screen was getting clogged up with green crap when I flushed out the winterising antifreeze a couple weeks back. I'm in the process of sanitising at the moment. I've got a bleach solution in there (concentrations as recommended in my Shurflo pump documentation). Need to flush the bleach out next time I'm down and hopefully it's not too much work to pull a new vent hose through.

[CaptUgly]

Mine had a loop in the vent hose. The low spot on the loop would fill with water & plug it. I had to shorten the hose. It should have a spot higher than the vent but not a loop.

[Four_Pyrates]

"CaptUgly" post=808589 wrote:
Mine had a loop in the vent hose. The low spot on the loop would fill with water & plug it. I had to shorten the hose. It should have a spot higher than the vent but not a loop.

The loop has a purpose. It keep spray and such out of the tank and should be mounted high enough where the spray goes in and up and then right back out. Most people put the loop in backwards or upside down so it holds water.

[builderdude]

"Four Pyrates" post=808608 wrote:

"CaptUgly" post=808589 wrote:
Mine had a loop in the vent hose. The low spot on the loop would fill with water & plug it. I had to shorten the hose. It should have a spot higher than the vent but not a loop.

The loop has a purpose. It keep spray and such out of the tank and should be mounted high enough where the spray goes in and up and then right back out. Most people put the loop in backwards or upside down so it holds water.

Agree, an upwards loop from the hulls vent fitting is how It should be, same for the fuel vent, holding tank vent not such a big deal if ya get some exterior water in there.

[tdcooper99]

Sorted my issues yesterday. Turns out my vent WAS plugged... badly. Gave it a few blasts of high-pressure water, and it opened up a tiny bit, but still took a lot of effort to blow even a little air through it... so I just bought a new one. 10 minute job to replace and voila, airflow! Before hooking up the vent hose, I back flushed it using the freshwater hose at my slip. The hose itself is pretty nasty looking, and definitely needs replacing... but I didn't have time to get into that yesterday. It's a reasonably short run, but I suspect it's going to be a bugger to deal with since the opening it goes through is VERY tight. The other issue was the pump wasn't shutting off at pressure and I was getting some fizziness at the tap, suggesting air getting in somewhere. I had bought a new pump some time ago, so I pulled all the fittings apart at the old pump to replace it with the new one and it turns out that one of the fittings on the suction side had not been put together with any PFTE tape or compound (a non-compression fitting). It wasn't leaking any water, but being on the suction side I could see how that might suck a little air in... especially since my vent was plugged causing a large vacuum to build up on that side of the system whenever the pump was on.

Anyway, long story short, new vent, vent hose backflush and new pump has sorted the issues. I might do one more sanitize with bleach to make sure whatever nasties I flushed back into the tank are dealt with. I'll take the old pump apart and see what needs doing... might be able to service the pressure shutoff switch and keep it as a spare.